Accepted Abstracts of the 9 International Conference ...

th

Accepted Abstracts of the 9 International Conference on Dendrochronology 2014

WorldDendro2014 Accepted Abstracts A RECONSTRUCTION OF TEMPERATURES USING TREE RINGS FROM GILGIT AND HUNZA VALLEYS OF KARAKORUM RANGE OF PAKISTAN 1

1

Moinuddin Ahmed* , Muhammad Usama Zafar , 1

Federal Urdu University of Arts, Science and Technology, Karachi-Pakistan

Abstract This Dendrocliamatological study used three species (Picea smithiana, Juniperus excelsa and Pinus gerardiana) ring-width chronologies to investigate palaeo-temperature history in Gilgit and Hunza valleys of Northern Pakistan. The resultant reconstruction is among the first palaeo temp. series using Picea smithiana. Picea smithiana Jutial chronology was used to reconstruct March-June temperatures back to A.D. 1523. The calibration model explained 38.16% of the variance in temperature. The reconstructed temperature was tested over decadal and century time-scale. The coolest decadal time scale period revealed that 17th century experienced lowest degree of temperature and ensuing the period of “Little Ice Age” (LIA). The temperatures reached their maximum in 19th century over century time-scale. As Pinus gerardiana Chaprot chronology exhibited strongest temperature signal among all chronologies therefore, separate exercise was performed where Jutial chronology reconstruction was compared with Chaprot reconstruction. Two species demonstrated the common pattern in spring temperatures. However, the temperature reconstruction from Chaprot was insufficient to produce a long term proxy temperature. The current reconstruction added similar trend of temperature in comparison with the other studies throughout central Asia. Theme: General Session Presentation Type: Oral USING WOOD PROPERTY CHRONOLOGIES TO DETECT CLIMATE SIGNALS 1

2

3

4

5

6

Kathryn Allen* , David Drew , Rob Evans , Michael Goddard , Geoff Downes , Patrick Baker 1

Melbourne School of Land and Environment, University of Melbourne, Richmond VIC CSIRO Ecosystems Sciences, College Rd, Sandy Bay, TAS 7005, Australia 3 Silviscan Pty Ltd, Doncaster East, VIC 3109, Australia 4 School of Biological Sciences, Monash University, 310 Blackburn Rd, Clayton 3800 5 Forest Quality, Franklin, TAS 7109, Australia 6 Melbourne School of Land and Environment, University of Melbourne, Richmond VIC 2

The Mt Read Lagarostrobos franklinii (Huon pine) ring-width chronology is one of the longest temperaturesensitive Southern Hemisphere chronologies. Yet, the occurrence of Huon pine at such a high elevation site is an ecological anomaly the majority of Huon pine grows at low elevation. Consequently, there is much more old material at low elevation sites. Unfortunately, ring widths of low elevation Huon pine do not crossdate well and exhibit a complex climate signal, therefore limiting further extension of the Australian treering-based climate record. Recently, however, we have developed well cross-dated chronologies from low elevation Huon pine using wood properties such as tracheid radial diameter, microfibril angles and cell wall thickness. These wood properties chronologies contain strong local and regional climate signals that rival the strength and spatial extent of the temperature signal contained in the high elevation Mt Read ring-width chronology. The regional temperature signal contained in the low elevation tracheid radial diameter chronology also appears more temporally stable than that in the Mt Read ring-widths. Wood property chronologies based on other sites and species in Tasmania are similarly promising and contain a clear climate signal where ring-widths do not. Our results strongly suggest further investigation of the value of wood properties chronologies is required, particularly in data-sparse areas where a clear climate signal in ring-widths has not been detected. The relative temporal stability of relationships between climate variables and wood properties chronologies may make them particularly important given ongoing concerns about divergence in some existing ring-width chronologies.

*Indicates presenting author.

2

WorldDendro2014 Accepted Abstracts Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Oral DYNAMICS OF NATURAL OLD-GROWTH FOREST ECOSYSTEM: SPATIAL AND TIME SCALE CONNECTIVITY OF PAST DISTURBANCES AND TREE ESTABLISHMENT OVER TWO CENTURIES 1, 2

1, 2

2

Jan Altman* , Jiri Dolezal , Pavel Fibich , Toshihiko Hara

3

1

Institute of Botany of the AS CR, Z¡mek 1, 25243 Prihonice, Czech Republic Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic 3 Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan 2

The globally observed trend of changing intensity of tropical cyclones over the past few decades emphasizes the need for a better understanding of the effects of such disturbance events. Tree-rings offer an excellent opportunity to investigate forest history; dendroecological methods provide high spatial and temporal resolution. Most of our knowledge about the influence of disturbances on forest stands was derived from studies in North America and Europe, whereas Asia remains less explored. Our objective in presented study was to determine the forest site disturbance history for conifer-hardwood mixed forest dominated by Quercus mongolica, Acer mono, Acer japonicum and Abies sachalinensis in Japan. We applied methods of dendrochronology for disturbance reconstruction over more than 200 years. In total, we measured and analysed more than 45,500 tree-rings from 385 trees of 15 species. We identified altogether 603 releases (293 moderate, 310 major) across all tree-rings. The average number of release events per tree was 1.6. Higher proportion of release events was identified for four periods: 1775-1784, 1815-1839, 1880-1909, and 19501984. Together in these four periods was detected 80% of all release events. In average, 19 trees was established (and survived up to 1998) in 5 year period in last 230 years. The rate of tree recruitment (at coring height) was noticeably higher in three periods: 1785-1834, 1910-1959, and 1985-1998. Finally, impact of past disturbances of different intensity on forest structure was studied on different spatial scales by spatial pattern analysis connected with the results of dendrochronological methods. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral RESPONSE OF TREES ON CHANGES IN FOREST MANAGEMENT: OAK REACTION ON CANOPY CLOSURE AND FLOOD CONTROL SYSTEM 1, 2

1, 2

2

Jan Altman* , Jiri Dolezal , Eliska Janska , Lukas Cizek

3

1

Institute of Botany of the AS CR, Z¡mek 1, 25243 Prihonice, Czech Republic Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic 3 Institute of Entomology, Biology Centre of the AS CR, Ceske Budejovice, CZ 2

Woodlands have been extensively managed all over Europe for centuries. The three most important management forms were coppicing, pollarding and wood-pasture. The intensification of forestry and agriculture and the abandonment of traditional silvicultural practices in the mid-20th century have resulted in an increase in the size of landscape mosaic grain, increased canopy closure, and a decline in the number of old and open-grown trees in both forested and agricultural landscapes. In addition, the abandonment of traditional management techniques has significantly influenced forest biodiversity. Succession from opencanopy forests and forests with frequent alterations of light and dark phases resulted in the decline of entire herb layer communities and species as well as critically endangered invertebrates. In the presented study, we focused on the growth of old oaks in the riparian forests in southern Moravia, Czech Republic. Our aims were to 1) detect the effects of canopy closure on previously solitary oaks, and 2) determine the impact of the levee construction on oak growth in regularly flooded area. We took increment cores from more than 200 oaks. Oaks from closed canopy forest, which were previously solitary trees (determined on characteristic features of solitary trees) were cored as well as oaks, which stayed solitary until nowadays. Time of the levee construction is known from archives. Presented study contributes to the discussion about oak decline in European woodlands. Due to low cutting intensity and subsequent competitive exclusion by shade-tolerant species oak is becoming unable to reach the mature phase. *Indicates presenting author.

3

WorldDendro2014 Accepted Abstracts Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Poster AUSTROCEDRUS CHILENSIS RESPONSE TO MEAN AND EXTREME CLIMATIC VARIABILITY ALONG A PRECIPITATION GRADIENT IN NORTHERN PATAGONIA, ARGENTINA. 1

1

1

Mariano Amoroso* , Eugenia Marcotti , Ricardo Villalba , Ignacio Mundo

1

1

Argentine Institute for Snow, Ice and Environmental Research, Mendoza, Argentina

The steep west-to-east precipitation gradient in the rain shadow of the Andes drives dramatic changes in vegetation patterns. As a result of this abrupt gradient, Austrocedrus chilensis populations develop at sites widely ranging in moisture, receiving as much as 2000 mm in the western limit and as little as 600 mm in the eastern limit of its distribution in the forest-steppe ecotono. This remarkable change occurs in a narrow strip of only 40 kilometers making this precipitation gradient one of the most abrupt in the globe. We conducted a dendroclimatological study to quantify and compare the influence of mean and extreme climatic variability on the radial growth of A. chilensis populations growing across this precipitation gradient. We sampled sites along the gradient to build tree ring chronologies to study climate-growth relationships. Correlation function analyses were used to study the influence of macroclimatic factors on tree growth. The effect of extreme climatic events (droughts) was studied by comparing tree growth during drought and post-drought years with the mean growth of the previous decade. Preliminary analyses indicate a strong relationship between radial growth and precipitation but this might vary across the gradient. While the growth response to the past major droughts varied across the gradient depending on the drought type and the site conditions, stands at high precipitation sites appeared to be the most affected. Studies on such dramatic precipitation gradients are of great importance as these areas will be strongly affected under the future climate scenarios. Theme: Z01. Other Presentation Type: Poster STAND RECOVERY AND SELF-ORGANIZATION FOLLOWING LARGE-SCALE MOUNTAIN PINE BEETLE INDUCED CANOPY MORTALITY IN NORTHERN FORESTS. 1

2

Mariano Amoroso* , K. Dave Coates , Rasmus Astrup

3

1

Argentine Institute for Snow, Ice and Environmental Research, Mendoza, Argentina Ministry of Forests, Lands and Natural Resource Operations, Smithers, Canada 3 Norwegian Institute for Forest and Landscape, Norway 2

A mountain pine beetle (MPB) epidemic is currently ravaging large areas of interior British Columbia (BC), Canada with significant implications for ecosystem services including future timber supply and community economic stability. Information is needed on future stand dynamics in areas of impacted forests that are unlikely to be salvaged logged. Predicting how surviving trees in these areas respond and grow and the timing and species composition of natural regeneration ingress is of critical importance for multiple forest values. We undertook a retrospective study in southeastern BC where an intense MPB epidemic peaked in 1979-1980. Our objective was to gain insight into stand recovery and stand self-organization as influenced by species-specific growth responses of different sized secondary structure trees (seedlings, saplings, and canopy trees surviving the epidemic) and post-beetle regeneration dynamics. MPB mortality rates, the percent of basal area killed by beetles, varied from 42 to 100%. In general, all surviving secondary structure released but the extent of growth release exhibited species variability. Ingress of natural regeneration was slow in the first few years after MPB attack but there was a strong pulse of recruitment 10-20 years post disturbance which then slowed considerably. Nearly 30 years after the MPB attack, the stocking and composition of the understories have changed dramatically. Overall, the occurrence of the MPB epidemic resulted in more structurally and compositionally diverse stands leading to multiple successional pathways different from those of even-age pine dominated stands. Theme: O09. Insect outbreaks *Indicates presenting author.

4

WorldDendro2014 Accepted Abstracts Presentation Type: Oral SMALL-SCALE INTERACTIONS BETWEEN WIND BLOWDOWN AND AVALANCHES SHAPE NOTHOFAGUS FORESTS IN SOUTHERN PATAGONIA. 1

1

1

2

2

Mariano Amoroso* , Ricardo Villalba , Marcos Radins , Ana Blazina , Matias Ruiz , Ana Srur

1

1

Argentine Institute for Snow, Ice and Environmental Research, Mendoza, Argentina Universidad Nacional de Cuyo, Mendoza, Argentina

2

Wind blowdowns and avalanches are important disturbances affecting the temperate mountain forests of southern Patagonia. In previous research, we reported for the first time the occurrence of wave regeneration after wind blowdowns in continental Nothofagus pumilio forests. Furthermore, we identified the presence of avalanche channels and debris in several blowdown patches, but it is unknown how these two disturbances may interact. We undertook a retrospective study to date wind blowdown and avalanche events to study the disturbance’s interaction and to reconstruct the overall forest structure and dynamics in Nothofagus pumilio forests in Santa Cruz, Argentina. We used (i) vegetation transects along the regenerating patches and adjacent undisturbed forests to reconstruct wind blowdown events, (ii) standard avalanche reconstruction methodology to date avalanche events, and (iii) transects along the entire study area to reconstruct overall forest structure and dynamics. Mortality and establishment dates, growth patterns, and scar dates were used in each case. The frequency and magnitude of wind blowdown events was highly variable. Pre-blowdown structure of the forest and wind intensity determined disturbance severity, leading to diverse post-blowdown structures in the regeneration patches. Avalanches followed blowdown events, but older events might have taken place as well. Their impact was larger at the highest elevation blowdown patches. The resulting stand structure exhibited a multimodal age distribution with many release events depicting the past multiple disturbance events. This study represents the first report of wind blowdown avalanche interaction for Nothofagus forests in Patagonia. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral STATISTICS AND MODELING OF DIVERGENCE IN NORTHWESTERN NORTH AMERICA 1

2

Kevin Anchukaitis* , Rosanne D'Arrigo , Laia Andreu-Hayles

2

1

Woods Hole Oceanographic Institution, Woods Hole, MA, USA Lamont Doherty Earth Observatory of Columbia University, Palisades, NY, USA

2

The Divergence Problem encompasses two, potentially non-exclusive, phenomena. 'Low frequency' divergence, where trends in temperature and tree-ring metrics over the last several decades differ, and 'high frequency' divergence, where the year-to-year correlation between climate and tree growth weakens or becomes insignificant. Neither phenomenon is ubiquitous. Here, we explore the spatial and temporal expression of high-frequency divergence in a new and updated set of Picea glauca tree-ring width chronologies from Alaska. Although temperature-growth relationships across our study region deteriorated through the 1980s and 1990s, in the 21st century the association reappears. Preliminary data suggest that divergence was most clearly associated with moisture stress. In order to provide mechanistic support for statistical interpretations of divergence, we use process-based models of tree-ring formation to investigate potential changes in limiting factors over time. Although the apparent and recent recovery of climate-tree growth relationships provides additional evidence for understanding the causes of divergence in this species and region, it does not alleviate concerns about the potential for divergence prior to the instrumental period. Maximum latewood density in this species in our study region does not appear to be subject to divergence, either high or low frequency. Theme: S01. Divergence and dendroclimatology Presentation Type: Oral


5

WorldDendro2014 Accepted Abstracts PROXY AND MODEL EVIDENCE FOR COUPLED PAN-PACIFIC DROUGHT MODES IN NORTH AMERICA AND ASIA 1

Kevin Anchukaitis* , Edward Cook

2

1

Woods Hole Oceanographic Institution, Woods Hole, MA, USA Lamont Doherty Earth Observatory of Columbia University, Palisades, NY, USA

2

A network of more than a thousand tree-ring chronologies across the Northern Hemisphere provides precisely dated annual resolution data on past droughts and pluvials spanning the last two thousand years (the Common Era). Hydroclimate reconstructions using these proxies consistently reveal epochs of anomalously dry and wet conditions of substantially greater magnitude and duration than those recorded over the last century of direct observations. Using networks of tree-ring chronologies from North America and Asia, in combination with long control simulations from general circulation models (GCMs) and other independent proxy records, we identify the extent and duration of these events and link their spatiotemporal fingerprint to large-scale modes of ocean-atmosphere variability. In particular, Pan-Pacific drought and pluvial patterns are linked to interannual and decadal variability in the El Nino-Southern Oscillation, while proxy and climate model evidence show that periods of weak interannual variability in the tropical Pacific coincide with rare but severe periods of synchronous North American and Monsoon Asian 'megadrought' and reveal additional influences. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral APPLICATIONS OF PROXY SYSTEM MODELING IN DENDROCLIMATOLOGY 1

2

3

1

Michael Evans , Susan Tolwinski-Ward , Kevin Anchukaitis* , Grace Duke , Malcolm Hughes

4

1

University of Maryland, College Park, MD USA Woods Hole Oceanographic Institution, Woods Hole, MA USA 3 National Center for Atmospheric Research, Boulder, CO USA 4 University of Arizona, Tucson, AZ USA 2

A proxy system model may be defined as the complete set of forward and mechanistic processes by which the response of a sensor to environmental forcing is recorded and subsequently observed in a material archive. Proxy system modeling complements and sharpens signal interpretations based solely on statistical analyses and transformations; provides the basis for observing network optimization, hypothesis testing, and datamodel comparisons for uncertainty estimation; and may be incorporated as weak but mechanistically-plausible constraints into paleoclimatic reconstruction algorithms. We review illustrations of these applications in treering research, and discuss emerging research directions. Theme: O02. Measuring and modelling wood formation Presentation Type: Oral ASIAN MONSOON CIRCULATION STRENGTH INFERRED FROM MULTICENTURY TREE-RING STABLE ISOTOPE CHRONOLOGIES FROM SOUTHEAST ASIA 1

2

3

4

5

Kevin Anchukaitis* , Mary Gagen , Dario Martin-Benito , Mariel Herzog , Manuel Hernandez , Allegra 6 1 3 LeGrande , Caroline Ummenhofer , Brendan Buckley 1

Woods Hole Oceanographic Institution, Woods Hole, MA, USA Department of Geography, Swansea University, Wales UK 3 Lamont Doherty Earth Observatory of Columbia University, Palisades, NY, USA 4 University of Colorado, Boulder, CO, USA 5 Texas A&M University, College Station, TX, USA 6 NASA Goddard Institute for Space Studies, New York, NY, USA 2

The large-scale dynamic circulation of the Asian monsoon over the last several centuries can be inferred from the oxygen isotope ratios of the annual rings of long-lived tropical conifer species from southeast Asia. Here, *Indicates presenting author.

6

WorldDendro2014 Accepted Abstracts we present replicated, multicentury stable isotope series from Fokienia hodginsii growing in the Bidoup Nui Ba National Park site in the southern highlands of Vietnam. This isotope chronology is significantly negatively correlated with summer monsoon surface wind speeds over the Bay of Bengal and the adjacent region, indicating that stronger (weaker) onshore winds are associated with lower (higher) oxygen isotope values. Ring width and isotopes show particular coherence at multidecadal time scales, and together allow past precipitation amount and circulation strength to be disentangled. Estimates of the strength of past monsoon circulation provide data for validating general circulation model simulations of the response of the Asian monsoon to changes in radiative forcing and an independent estimate against which to evaluate long-term changes in the Asian monsoon as reflected in other terrestrial and marine proxies as well as forced last millennium general circulation model simulations. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Poster HOW TO IDENTIFY DISTINCT REGIONAL AND SEASONAL PATTERNS OF ATMOSPHERIC VARIABILITY USING TREE RINGS AND STABLE ISOTOPES FROM THE IBERIAN PENINSULA AND LINKS TO HISTORICAL ARCHIVES 1,2

3

2,4

5

5

Laia Andreu-Hayles* , Caroline Ummenhofer , Mariano Barriendos , Gerhard Helle , Gerhard H. Schleser , 6 4 1 Markus Leuenberger , Emilia Gutierrez , Edward R. Cook 1

Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA Institut Catalo de Cio ncies del Clima (IC3), Barcelona, Catalonia, Spain 3 Woods Hole Oceanographic Institution, Woods Hole, MA, USA 4 University of Barcelona, Catalonia, Spain 5 German Centre for Geosciences, Potsdam, Germany 6 University of Bern, Bern, Switzerland 2

This work seeks to validate different approaches to understand the relative contribution of Mediterranean and Atlantic atmospheric influences on several sites across the Iberian Peninsula for the last 400 years combining the information recorded by both tree rings and historical archives with field correlation and climate dynamical analyses. We found that measuring stable carbon (Î´13C) and oxygen (Î´18O) isotope ratios, which is more expensive and time-consuming than measuring the classical ring-width parameter, provides an added value by better capturing large-scale climatic features than ring-width, which is often more dependent on local conditions. Spatial correlations between tree rings and gridded climate products demonstrate that the isotope signatures in the targeted Iberian pine forests are very sensitive to water availability during the summer period because they are strongly dominated by stomatal conductance. In agreement, composite anomalies during years with extreme high (low) stable isotopic values in the tree-ring records displayed coherent large-scale atmospheric circulation patterns with reduced (enhanced) moisture flux for the different sites. Moreover, these analyses of extremes revealed that high/low proxy values do not necessarily correspond to mirror images in the atmospheric anomaly patterns, suggesting different drivers of these patterns and the corresponding signature recorded in the proxies. Therefore, this non-linear approach provides information not available with standard techniques. We used this approach in multiple comparisons among tree rings, instrumental/reanalysis products, and historical archives to extend our analyses for different seasons to past centuries. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral A PRIORIA COPAIFERA TREE-RING WIDTH CHRONOLOGY FROM THE COLOMBIAN TROPICAL PACIFIC 1

1

2

David Herrera , Jorge Ignacio del Valle , Laia Andreu-Hayles* 1

Universidad Nacional de Colombia sede Medella-n, Colombia Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA

2

The Tropical Pacific region in Colombia is the rainiest in America and one of the most important biogeographically hotspots worldwide. Tropical dendrochronology can potentially provide long-term climatic *Indicates presenting author.

7

WorldDendro2014 Accepted Abstracts records extremely needed considering first, the lack of climatic data for this region, and second, the high ecosystem and population vulnerability to the ongoing climatic change. Our study site (7°20' N, 77°57' W) is located at the low Atrato river that has very high levels of streamflow during almost 9 months usually from May to December causing strong flooding over large areas. Prioria copaifera, known as cativo, is a tropical tree-legume species growing in the Atrato floodplains that forms tree rings defined by marginal lines of parenchyma. Fifteen cross-sections were visually cross-dated and measured, and as a result a tree-ring width chronology was successfully established for P. copaifera spanning from 1830 to 2006. The annuality of the tree rings was confirmed by several 14C dates and significant correlations were found between this chronology and hydroclimatic variables. P. copaifera radial growth correlates strongly with fluctuations of water levels and streamflow of the Atrato river. Other significant relationships were also found with precipitation, Sea Surface Temperatures (SST), and global circulation indices such as the Pacific Decadal Oscillation (PDO), the Oceanic Niño Index (ONI), the Southern Oscillation Index (SOI) and the low-level westerly jet stream of the Pacific coast of Colombia (Choco jet). Our next challenge will be to reconstruct past hydroclimate conditions in this region based on our treering records. Theme: O01. Tropical dendrochronology Presentation Type: Poster DIFFERENTIATING BETWEEN MOUNTAIN PINE BEETLE AND FIRE SCARS IN LODGEPOLE PINE 1

Estelle Arbellay* , Lori D. Daniels

1

1

University of British Columbia, Vancouver, Canada

The mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) and fire are two major disturbance agents in forests of British Columbia. As both agents leave scars on lodgepole pine (Pinus contorta Douglas) trees, some difficulty may arise in differentiating between the types of scars on samples. Scars may occur on the same sample in different years or, in some cases, there may be simultaneous activity of the two agents within the same year. While fire scars have been described and have recently started to be analyzed for changes in wood anatomy and wood chemistry, little information exists on the fine-scale attributes of scars resulting from insect strip attack. The identification of scars as either MPB or fire origin mostly relies on basic qualitative characteristics cited in pioneer studies on the topic, such as scar morphology, bark presence and fungal stains in the wood. Therefore, we intend to conduct research on both types of scar using a multi-proxy approach of various features in wood anatomy and wood chemistry. The aim is to study radial variations of wood traits and determine which ones significantly change as a result of scarring (of either origin). Here we outline some considerations in sample selection for fine-scale analysis at the wound margin and present some preliminary results on wood anatomy and/or wood chemistry. The ultimate goal of differentiating MPBinduced wounding from that induced by fire is to improve the reconstruction of insect outbreaks and forest fires. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Poster FIRE SCARRING AFFECTS WOOD FORMATION IN NORTH AMERICAN CONIFERS: ANATOMICAL EVIDENCE FROM TRACHEIDS, RAYS AND RESIN DUCTS 1

2,3

4

5

Estelle Arbellay* , Markus Stoffel , Elaine K. Sutherland , Kevin T. Smith , Donald A. Falk

6,7

1

Tree-Ring Lab at UBC, University of British Columbia, Vancouver, Canada Laboratory of Dendrogeomorphology, University of Berne, Switzerland 3 Department for Environmental Sciences, University of Geneva, Switzerland 4 USDA Forest Service, Forestry Sciences Laboratory, Missoula, USA 5 USDA Forest Service, Northern Research Station, Durham, USA 6 School of Natural Resources and the Environment, University of Arizona, Tucson, 7 Laboratory of Tree-Ring Research, University of Arizona, Tucson, USA 2


8

WorldDendro2014 Accepted Abstracts Fire is a major disturbance agent in North American forests. Fires injure trees when heat transfer through the bark partially kills the cambium and the compartmentalization process results in a fire scar. Dendrochronologists use these scars in the xylem to reconstruct fire regimes. However, little information exists on the wood microanatomy of fire scars. This study investigated regular xylem and wound xylem of Pseudotsuga menziesii, Larix occidentalis and Pinus ponderosa in order to quantify anatomical changes caused by fire-induced wounding. Transverse and tangential microsections were cut from samples for light microscopy. Anatomical measurements of tracheids, rays and resin ducts were performed in the three spatial dimensions: axially - at 4 different heights along the fire scar; radially - in pre-fire and post-fire rings; and tangentially - within 4 cm from the wound margin. All three species produced a first post-fire ring made of narrower and more numerous tracheids, reaction that was more marked closest to the scar. In P. menziesii and L. occidentalis, increases in ray size and ray density were also observed. In P. ponderosa, however, no such patterns were identified. Moreover, P. menziesii formed narrower axial resin ducts, whereas L. occidentalis displayed wider resin ducts in both the axial and radial directions. P. menziesii did not adjust the size of radial resin ducts to adapt to fire disturbance. These results provide new insights into the spatio-temporal extent of fire-induced wound effects in the xylem of conifers, which will be useful in perfecting the identification and dating of fire scars. Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Poster A CROSS-BORDER ANALYSIS OF FIRE REGIMES IN THE US-MEXICO BORDERLANDS 1

1

Alexis Arizpe* , Donald Falk , Mark Kaib

2

1

University of Arizona, Tucson, USA US Fish and Wildlife Services, Albuquerque , USA

2

Pine forests of the Southwestern United States were characterized historically by high-frequency, low-severity surface fire events evident in the tree-ring record. Twentieth century fire suppression has disrupted these fire regimes in US forests leading to recent unprecedented fire severity and behavior across the Western US. Forests of Northwestern Mexico are similar in both species composition and climate to Southwestern US forests, however land management and historical practices are different. We have characterized fire regimes across five sites ranging from the northern extent of the Sierra Madre in Eastern Sonora, to the Madrean Archipelago of sky islands across the US-Mexico border. Synchronous fires are seen across sites, although not across all sites. The 20th century in US fire regimes is marked by a decrease in fire frequency seen in other studies. The presence of frequent 20th century fires in Mexico provides a unique opportunity to characterize modern surface fire regimes under changing climate, and to look at fire climate interactions of surface fires with instrumental records. These sites provide a needed proxy for understanding fire regimes, forest resilience and climate change across the western US in forests analogous to historic ecosystems. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral 2000 YEARS OF CLIMATE FROM PINE TREE-RING δ13C AND GROWTH RATES FROM NORTHERN FINLAND 1

2

3

1

Laura Arppe* , Samuli Helama , Kari Mielikainen , Markku Oinonen , Mauri Timonen

2

1

Finnish Museum of Natural History Laboratory of Chronology, Helsinki, Finland Finnish Forest Research Institute, Rovaniemi, Finland 3 Finnish Forest Research Institute, Vantaa, Finland 2

Tree-ring archives of stable carbon isotopes (δ13C) have proven to be an excellent source of palaeoecological and palaecoclimatic information about photosythesis, the data thus yielding indirect estimations of temperature, moisture and cloudiness. Here we use a collection of modern and subfossil pinewood from northern Finnish Lapland for extracting of δ13C variations on an absolute decadal timescale for the Common Era (AD/CE 1-2012). Dendrochronologically cross-dated tree-ring material was dissected from living-tree and megafossil samples and the pinewood cellulose was analysed for δ13C. The combined dataset comprises 1454 *Indicates presenting author.

9

WorldDendro2014 Accepted Abstracts decadal samples (433 of modern wood and 1021 of subfossil wood), ensuring a sample replication of n=5. The time series of individual stems were combined to construct mean chronologies. Our new δ13C record shows new evidence for palaeoecological and palaecoclimatic anomalies through the little ice age, medieval warm period, as well as the pre-medieval anomalies, with comparisons to the 20th century δ13C levels. The lowfrequency variations of the δ13C chronology can also be used for discussing the Milankovitch scale trends in climate and sub-arctic environment. Our work continues to produce the δ13C chronology for mid Holocene (5500 BC/ BCE through AD/CE 2010). Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral

B DIVERGENCE IN THE SOUTHERN HEMISPHERE 1

1

2

3

4

4

Patrick Baker* , Kathy Allen , Edward Cook , David Drew , Pavla Fenwick , Jonathan Palmer , Ricardo Villalba

5

1

University of Melbourne, Melbourne, Australia Lamont-Doherty Earth Observatory, Palisades, USA 3 CSIRO, Hobart, Australia 4 Gondwana Dendro, Christchurch, New Zealand 5 Ianigla-Conicet, Mendoza, Argentina 2

The relative paucity of climate-sensitive, multi-millennial tree-ring chronologies in the Southern Hemisphere makes it particularly important to examine whether the existing chronologies exhibit signs of the Divergence Problem (DP) identified in the Northern Hemisphere. Identification of potential divergence in Southern Hemisphere tree-ring chronologies has been hampered by the fact that most have not been updated to include the 1990s and 2000s. We are currently updating climate-sensitive chronologies from Australia, New Zealand and South America and examining both low- and high-frequency components of the chronologies for divergence. Our investigation includes examination of standardisation issues and the potential impact of signal-free processing in chronology development. A recently developed signal-free Huon pine chronology from Mt Read in Tasmania shows no evidence of decreasing ring widths with increasing temperatures. Rather, the chronology appears to be growing faster than expected based on temperatures for the site. We are also assessing whether relationships between climate and wood properties chronologies (e.g., based on tracheid radial diameter, density, microfibril angle) may be more temporally stable than for ring-width chronologies. The use of high-resolution dendrometer data to assist us to better understand the climate response of trees at key sites is a critical component of our study and extends it beyond simple identification of divergence. This high-resolution data has highlighted the complexity of the cambial response to climate even at the high elevation and temperature-sensitive Mt Read site. Theme: S01. Divergence and dendroclimatology Presentation Type: Oral ANALYZING THE IMPACT OF MECHANICAL DAMAGE CAUSED BY FLOODS THROUGH X-RAY COMPUTED TOMOGRAPHY AND VARIOGRAM TOOLS 1

1

2

Juan Antonio Ballesteros Canovas* , Markus Stoffel , Carolina Guardiola-Albert , Andres Do-ez-Herrero

2

1

Lab. of Dendrogeomorphology, University of Berne, CH-3012, Berne, Switzerland Geological Survey of Spain (IGME), Ro-os Rosas 23, Madrid E-28003, Spain

2

Anatomical responses of trees following mechanical wounding have been described widely in the literature. As a result of time consuming analysis, however, only limited data is available the on the spatial extent of wound responses as well as on factors controlling wound closure. Here we combine XRCT imagery and geostatistics (variogram analyses) to document the response of riparian trees to wounding by floods and their subsequent


10

WorldDendro2014 Accepted Abstracts recovery. We document 3D wood density changes in 37 trees from three Mediterranean riparian species (Alnus glutinosa, Fraxinus angustifolia and Salix atrocinerea). In addition, we quantify tree and wound characteristics (e.g. wound size, decayed area, callus length and callus mark, tree characteristics and growth patterns) and the reaction of trees to wounding as a function of their health state. Based on non-parametric statistical tests and principal component analysis we describe possible controls of macroscopic variables on the radial affected area, the decay process and recovery capacity of trees after cambial wounding. Reactions in trees are controlled differently between species, but are driven above all by the tree’s health state prior to wounding. Results of this study are relevant for Mediterranean ecosystems, and in particular in terms of the cycle-of-life of riparian vegetation under climate change scenarios where an increase in the frequency of hydrogeomorphic processes may result in a decrease the health status of riparian trees Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral FLOODS PEAK DISCHARGE ESTIMATION BASED ON DEFORMATION OF TILTED TREES 1

2

2

2

Juan Antonio Ballesteros Canovas* , Mauricio Sanchez-Silva , Fernando Márquez , Andres Do-ez-Herrero , Jose 3 1 1 4 Maria Bodoque , Virginia Ruiz , Markus Stoffel , Eguibar Miguel Angel 1

Lab. of Dendrogeomorphology, University of Berne, CH-3012, Berne, Switzerland Universidad de los Andres, Bogota, Colombia 3 Geological Survey of Spain (IGME), Rao os Rosas 23, Madrid E-28003, Spain 4 Universidad de Valencia, Valencia, Spain 2

Tilted trees are one of the most common dendrogeomorphological evidence of past flood events. They have been widely used to reconstruct flood frequency by means reaction wood, but their usefulness for discharge estimation has never been studied. In this communication, we present a new approach based on mechanical tree deformation-flood depth model to study the relationship between observed deformation and flow discharges. Therefore, we combine theories from dendrogeomorphology, dendrometric, mechanical structures and hydraulic sciences to model the elastic and plastic behavior of roots anchorage in the process. Needed input data that were measured in the field are: stand forest characteristic, tilted tree characteristic, results from reaction wood analysis; results from 2-D hydraulic model and soils characteristic description. In addition, a 3D georadar work has been carried out to define root-plate architecture. Model validation has been carried out in three reach rivers with available gauge data in the central part of Spain. Results from 34 analyzed tilted trees showed a moderate correlation between observed and modeled discharges (~0.65). Controls on this variability have been determined and related with the tree age in which the tree when was tilted as well as the signal-noise in deformation due to subsequent events and the likely increase of the exposed surface by ephemeral woody jumps. Model limitations and usefulness are deeply discussed, but certainly results may be used as censored data for flood hazard definition as well as for flood frequency analysis that can be extended to ungauged or poorly gauged catchments. Theme: O07. Dendrogeomorphology Presentation Type: Poster 250 YEARS OF FLASH-FLOOD ACTIVITY IN AN UNGAUGED, MANAGED MOUNTAIN FOREST CATCHMENT (VALSAÍN, CENTRAL SPAIN) 1

2

3

Juan Antonio Ballesteros Canovas* , Clara Rodríguez-Morata , Virgina Garofano-Gomez , Juan Manuel 4 5 6 6 1 7 Rubiales , Raul Sa¡nchez-Salguero , Ramzi Touchan , Dave Meko , Markus Stoffel , Andres Diez-Herreo , Jose 8 Maria Bodoque 1

Lab. of Dendrogeomorphology, University of Berne, CH-3012, Berne, Switzerland Complutense University of Madrid, Madrid, Spain 3 University of Valencia, Valencia, Spain 4 Technical University of Madrid, Madrid, Spain 5 University of Cordoba, Cordoba,Spain 6 Laboratory of Tree-Ring Research, University of Arizona, Tucson, USA 2


11

WorldDendro2014 Accepted Abstracts 7

Geological Survey of Spain (IGME), Ra-os Rosas 23, Madrid E-28003, Spain University of Castilla-La Mancha, Toledo, Spain

8

Past flash-flood activity was assessed in a historically managed mountain forest catchment located in the Central part of Spain using growth disturbances in old Pinus sylvestris L. trees. The objective of the research is to present a case study on the role of dendrogeomorphology in reconstructing and understanding flash floods in this region that was heavily managed in the past.. The high gradient mountain stream analysed is known as Arroyo de los Puentes; it starts at 2258 masl and joins the Arroyo de Pintadas at 1500 masl, creating a relatively wide alluvial cone covered by well-preserved pine tree woodlands. A total of 235 disturbed trees (with scars on their main stem, tilted, decapitated and uprooted trunk) were sampled within the area of the stream influenced by floods. wo additional reference chronologies were evaluated from the upper and lower parts of the catchment to incorporate the signal related to forest management practices into the analysis. An index was calculated considering the type of growth disturbance, replication and sample depth. The tree-ring sequences sampled allowed reconstruction of several flash-flood events since AD 1700. Climatological triggers of two extreme floods of the last 77 years were compared. . Further research will be oriented to the definition of the frequency and magnitude of specific flash floods in the Sierra de Guadarrama with the aim to improve hazard and risk analysis. Theme: O07. Dendrogeomorphology Presentation Type: Oral A NEW TREE-RING NETWORK REVEALS PECULIAR CLIMATE MODES IN PREHISTORIC LAKE BONNEVILLE AND MODERN-DAY GREAT SALT LAKE, USA 1

2

3

Matt Bekker* , Shih-Yu (Simon) Wang , Justin DeRose , Brendan Buckley

4

1

Brigham Young University, Provo, USA Utah State University, Logan, USA 3 US Forest Service Rocky Mountain Research Station, Ogden, USA 4 Lamont Doherty Earth Observatory, New York, USA 2

Climate in the western United States exhibits marked low-frequency variability influenced by such climate modes as PDO and AMO, and complex interactions with terrain makes long-term forecasts difficult. Recent research has indicated that a peculiar climate mode called the Pacific Quasi-Decadal Oscillation (QDO) has a dominant effect on climate in the Intermountain West, producing a distinct quasi-decadal fluctuation revealed in many hydroclimatic variables. These fluctuations are recorded by the elevation of the Great Salt Lake (GSL) and regional tree-ring records. Over the past 4 years, the Wasatch Dendroclimatology Research (WADR) Group has developed an extensive network of tree-ring chronologies covering the entire GSL watershed. These chronologies were used to reconstruct hydrologic variables such as streamflow, and teleconnections such as the QDO. Moreover, we reconstructed the GSL elevation back to A.D. 1429 and up to 2005. The reconstruction indicated three pre-instrumental extreme wet events rivaling the flood years 1983 -1986, and two drought events that were much greater in magnitude than anything during the post-1900 record. Based upon the close association between the GSL elevation and the Pacific QDO, a statistical model was developed to predict the GSL elevation. The model was able to replicate and forecast turnarounds in the GSL elevation, i.e. where prolonged increasing trends were followed by persistent decreases and vice versa. A forecast of the GSL elevation out to 6 years was shown to verify well with the post-2005 observations. This work represents a successful example in the combination of tree-ring data, climate dynamics, and empirical forecasting. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral THE (VERY GOOD) DENDROCHRONOLOGICAL POTENTIAL OF UTAH JUNIPER (JUNIPERUS OSTEOSPERMA) IN NORTHERN UTAH 1

2

3

Matt Bekker* , Justin DeRose , Roger Kjelgren , Brendan Buckley

4

1

Brigham Young University, Provo, USA


12


US Forest Service Rocky Mountain Research Station, Ogden, USA Utah State University, Logan, USA 4 Lamont Doherty Earth Observatory, New York, USA 3

Utah juniper (Juniperus osteosperma) is used rarely in dendrochronological studies and has not been previously shown to crossdate across sites. We introduce two newly-collected Utah juniper chronologies in northern Utah with very strong internal crossdating, and moderate correlations between the sites. They also crossdate very well with a previously developed Utah juniper chronology in southwestern Wyoming, and with pinyon pine (Pinus edulis) chronologies in the region. The tree-ring indices correlate positively to early summer rainfall but negatively to summer temperature, suggesting a direct climate impact on growth rather than a proxy relationship. They are also strongly correlated with local and regional streamflow, and preliminary results suggest that the species may also be useful in reconstructing water demand as well as supply; yearly ring increment tracks May-June water deficit (precipitation minus evapotranspiration) quite well during some periods. Utah juniper and Rocky Mountain juniper (Juniperus scopulorum) hybridize, which may have contributed to crossdating success, but most trees sampled are undoubtedly Utah juniper, and our results suggest that this species should be given more serious consideration in future dendrochronological studies, particularly outside the range of more traditionally used species such as pinyon and ponderosa pine and Douglas-fir. Theme: Z01. Other Presentation Type: Poster HIGH RESOLUTION ANALYSIS OF STEM RADIUS VARIATIONS IN BLACK SPRUCE SUBJECTED REPEATED DROUGHT 1

1

1

Evelyn Belien* , Hubert Morin , Sergio Rossi , Annie Deslauriers

1

1

Universite du Quebec Chicoutimi

In the near future, climate warming is expected to produce more severe and frequent periods of drought with consequent water stresses for boreal species. The effect of drought on plant growth and survival are frequently studied in tropical and European regions and often shown to be disastrous. In this study, we are looking at the consequences of summer drought on mature black spruce trees in the boreal environment. We present a high resolution analysis of chronologies of stem radius variations in black spruce under rain exclusion. Prolonged rain exclusions were applied for three consecutive summers to trees on four sites along a latitudinal gradient. The stem radius variations of control and treated trees were monitored year-round at an hourly resolution with automatic point dendrometers. The seasonal patterns of shrinking and swelling were analyzed using a sequential analysis technique and the daily patterns of contraction and expansion were extracted. Overall, the treated trees followed their daily cycles of contraction and expansion during the rain exclusions and no cumulative difference in stem expansion was observed over the three years. Trees subjected to rain exclusion showed larger stem contractions in summer on three out of four sites and larger winter contractions were observed on the northern sites. This study shows that a repeated summer drought does not necessarily lead to a direct evident stress reaction, showing the resilience of the boreal forest. Theme: O08. Drought and mortality Presentation Type: Oral TREE-RING ANALYSIS OF TEAK (TECTONA GRANDIS L.) FOR CLIMATE AND ECOLOGICAL STUDIES FROM PENINSULAR REGION OF INDIA 1

1

Amalava Bhattacharyya* , Santosh K. Shah* 1

Birbal Sahni Institute of Palaeobotany,53- University Road-226 007, Lucknow, Ind

Tree-ring analysis of Teak (Tectona grandis L.) for climate and ecological studies from peninsular region of India Analysis of tree ring data Teak (Tectona grandis L.) growing under tropical deciduous and semi evergreen forest of peninsular region of India from the central and southern part of India respectively signify its *Indicates presenting author.

13

WorldDendro2014 Accepted Abstracts importance in ecological and climatic studies. The study from central India showed potentiality of the teak in the reconstruction of monsoon precipitation of June-September which goes back to AD 1835. Teak analyzed from semi evergreen forest at Perambiculum,Kerala southern India exhibits positive tree growth/climate relationship with precipitation during May of current year, and October and November of the prior year which suggest that both pre-monsoon and post monsoon play important role in controlling growth of this tree. Reconstruction of May precipitation during AD 1590-2000 based on tree ring data of this region and its correlation with other global climate parameters El.Nino/ENSO has been made. The study also shows that apart from ring-width, the other parameter of tree ring ie., Mean Vessel Area (MVA) of early wood is also found suitable for climatic reconstruction. The climate reconstruction based on the teak tree-ring width and mean vessel area showed several alternating periods of high and low monsoon episodes. Many of these low monsoon years have been recorded to coincide with most of the known principal drought years of India. Theme: O01. Tropical dendrochronology Presentation Type: Oral HAS DROUGHT ANY INFLUENCE ON OAK DECLINE IN POLAND? 1

Mirela Tulik , Szymon Bijak*

1

1

Warsaw University of Life Sciences-SGGW, Warszawa, Poland

Oak decline is a complex process leading to increased mortality of this species. It has been observed in Europe for many years. So-far researches suggest that drought might be one of the most important causing factors. Study investigates radial growth of pedunculate oak (Quercus robur) of various health status as well as its response to climate conditions, especially of water shortage. Sample material comprised of increment cores taken at two sites (western and central Poland, 15 trees each). Three health classes (healthy, weakened and dead) were distinguished basing on the defoliation level. Transverse sections were prepared from cores with sliding microtome and Cell P image analysis software was used for measurements. We investigated following tree-ring features: ring width (TRW), vessels density (VD), nonweighted and hydraulically weighted vessels diameter (HWVD and HNVD, respectively), and theoretical hydraulic conductivity based on Hagen-Poisseuille law (HC). We correlate them with mean monthly temperature (T), precipitation (P), PDSI values and water availability index (WAI=P/T) for 1980-2008 period. Radial increments and anatomical parameters values were significantly higher for healthy oaks than weakened and dead trees. TRW showed smaller dependence on climate than analysed anatomical attributes. All these features correlated significantly with temperature in April-August and precipitation in February-June period regardless the health conditions. No relationship was found between oak radial growth and PDSI values, while correlation with April and June WAI was significant for anatomical attributes. Our results revealed that drought had not direct impact on the process of oak decline on investigated plots. Theme: O08. Drought and mortality Presentation Type: Oral IS BLUE INTENSITY READY TO REPLACE MXD IN CLIMATE RECONSTRUCTIONS? 1

1

1

Jesper Björklund* , Kristina Seftigen , Hans Linderholm 1

Gothenburg University, Gothenburg, Sweden

Where tree-growth is mainly limited by temperature, Maximum Latewood Density (MXD) derived from x-ray measurements has on several occasions been shown to be a superior proxy to that of tree-ring widths. X-ray analyses are however expensive and laborious, which have triggered experimentation with other methods of deriving similar information from tree-rings, e.g. optical flatbed scanners to produce Minimum Blue Intensity (BImin). Previous studies have shown that BImin is an excellent proxy for MXD on annual to decadal scales. Here we present the first test that truly investigates the skill of BImin on chronologies consisting of multiple generations of trees. The results from analyses on a new 800-year long Scots pine chronology from Northern Sweden corroborates previous studies, but also show that BImin is very limited on decadal and longer timescales. Discolouration between samples is curbing BImin, where a specific brightness can have different *Indicates presenting author.

14

WorldDendro2014 Accepted Abstracts densities. A new density parameter was investigated which could possibly overcome this issue: δ blue intensity (δ BI), defined as BImin - BIEW = δ BI where BIEW is the blue intensity in the earlywood which is used to provide a brightness baseline to the BImin measurements. The methodology was previously explored on x-ray material and showed great promise. We here attempt to test this methodology also on blue intensity material. If the new Î” BI parameter can match MXD in skill on multiple generation chronologies, it will be of great value since blue intensity is far less expensive than the x-ray methodology. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral TREE GROWTH IN RELATION TO GROWING SEASON CHANGES – COMBINING DENDROCHRONOLOGICAL AND PHENOLOGICAL DATA 1

1

1

1

1

Jesper Björklund* , Petter Stridbeck , Mauricio Fuentes , Kristina Seftigen , Hans Linderholm 1

Gothenburg University, Gothenburg, Sweden

An increasing number of studies have reported on shifts in timing and length of the growing season (GS), based on phenological, satellite and climatological data. The growing season has been lengthened by ca. 10-20 days in Fennoscandia in the last few decades, associated with recent global warming. Changes in the timing and length of the GS may have far-reaching consequences for plant and animal ecosystems, but persistent increases may also lead to long-term increases in carbon storage and changes in vegetation cover which may affect the climate system. The growth of commercial tree species in Sweden are of important environmental and economic interests, and it is central to understand how changes in GS parameters (beginning, end, duration, and the weather characterizing it) may affect the growth of trees to calculate future yields. This study is mainly based on phenological observations (timing of the year of budding and leaf senescence etc.) and dendroclimatological climate response analyses of a network of Scots pine and Downy birch chronologies from northern Sweden. The dendroclimatological approach will make use of daily data where moving window correlations between annual tree-growth and climate will be performed to reveal more precisely the timing of the GS. This analysis can determine stability and possible changes in responses over time. The availability of high-quality dendrochronological and daily meteorological data for the last century across this region makes Sweden an excellent location for these kinds of studies. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Poster TREE-RING POTENTIAL OF SOME CONIFER SPECIES FROM AZAD JAMMU AND KASHMIR-PAKISTAN 1

2

Tasveer Bokhari* , Moinuddin Ahmed , Saeed Malik

1

1

Institute of Biology, Bahauddin Zakariya University, Multan-Pakistan Department of Botany, Fuuast, Karachi-Pakistan

2

The Tree-ring study of fifteen conifer forests from seven sites of Azad Jammu and Kashmir-Pakistan was conducted. Core samples from five conifer tree species were taken. Those species were Abies pindrow (Royle ex D.Don) Royle, Cedrus deodara (Roxb.) G. Don., Picea smithiana (Wall.) Boiss., Pinus roxburghii Sargent and Pinus wallichiana A.B. Jackson. Abies pindrow and Cedrus deodara gave long series with sensitive ring sequences from four sites (Pir Chinasi, Sudhan Gali, Kail and Keran) which were cross matched successfully. These two species showed signs of past disturbances like scars, wounds, cracks and sensitive rings due to earthquakes, landslides, fire etc. Raw and standardized versions of tree ring chronologies of these species from four sites were developed. Abies pindrow chronology extended back to 1697-2009 A.D. for 312 years from Sudhan Gali. Among all the species, Abies pindrow showed the maximum age of 336 years. However, other species attained more than hundred years of age. The maximum radial growth was also observed in Abies pindrow with the value of 0.47cm per year respectively. On the other hand the growth rate of Cedrus deodara was slow i.e. about 0.30 cm per year respectively. The dbh and growth rate of most of the trees from sampled forests were negatively while dbh and age were positively correlated.


15

WorldDendro2014 Accepted Abstracts Theme: Z01. Other Presentation Type: Poster WHERE DID THE KAURI FOREST GO? DENDROARCHAEOLOGY AND THE KAURI TIMBER TRADE 1

2

Gretel Boswijk* , Martin Jones 1

School of Environment, The University of Auckland, Auckland, New Zealand New Zealand Historic Places Trust Pouhere Taonga, Auckland, New Zealand

2

As European settler societies developed in the New World, forests were exploited to compensate for timber deficits elsewhere, as well as meet growing local demand. Initially connected to the global timber trade in the late eighteenth century, New Zealand (NZ) both exported and imported significant quantities of timber during the nineteenth and early twentieth centuries. The primary export timber species was kauri (Agathis australis), which grows naturally only in the northern part of the country. Between 1820 and 1920 the kauri forests were heavily exploited, providing timber and capital for the colony, and opening up land for pastoral farming. Large quantities of timber were shipped from harbours in the upper North Island to destinations elsewhere in NZ and overseas. In particular, Australia was an important market for baulk and sawn timber, but kauri was also dispatched elsewhere including America and Britain. In this paper, we aim to show how the dendroarchaeological investigation of the fabric of standing structures can provide insight into the kauri timber trade by providing physical evidence of where, how and when kauri timber was employed. In turn, this extends our knowledge of where the kauri forest went; some of the demands that stimulated its destruction; and how these aspects changed over time. Because kauri are large and long-lived, the tree ring data generated from archaeological wood also informs understanding of the ecology of pre-European (and potentially preMāori) kauri forest and is an important component of data sets used to reconstruct climate during the second millennium CE. Theme: General Session Presentation Type: Oral THE 4500-YEAR KAURI CHRONOLOGY: A BIT FATTER AND A BIT LONGER, BUT IS IT A BIT MORE USEFUL? 1

1

Gretel Boswijk* , Anthony Fowler , Jonathan Palmer

2

1

School of Environment, The University of Auckland, Auckland, New Zealand Climate Change Research Centre, University of New South Wales, Sydney, Australia

2

Long, high resolution proxy records, such as those provided by tree rings, provide essential context for contemporary variability in climate, and for investigating forcing mechanisms of change. Constructing long tree ring records requires living species and preserved wood that ideally grew in similar ecological environments and which are assumed to express a common climate response. Whilst supra-long chronologies have been built from living trees, historical and archaeological timbers, and sub-fossil wood, there is uncertainty about the utility of such records for palaeoclimate reconstruction due to the changing sources of material. A 4491year composite tree ring chronology has been built from New Zealand kauri (Agathis australis), providing a potentially valuable ENSO sensitive proxy from the south-western Pacific. However, the late-Holocene kauri chronology (LHKC) is a composite record based on modern and archaeological (= historical) material (911-2002 CE) and sub-fossil (swamp) material (2488 BCE-1286 CE). The modern and swamp trees grew in different environments, potentially affecting the usefulness of the entire LHKC as a climate proxy. To establish utility it is important to know the data set. Therefore, this paper: (a) describes the composition of the LHKC, including recent additions and extensions; (b) outlines differences in the character of the three sub-groups; (c) assesses the strengths and weakness of the composite chronology; and (d) identifies current uncertainties and potential biases associated with the complex composition of the LHKC that may affect climate reconstructions. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Poster


16

WorldDendro2014 Accepted Abstracts DROUGHT IMPACT ON BEECH (FAGUS SYLVATICA L.) FORESTS IN THE NORTH-WEST OF ITALY. A DRIVER OF FUTURE FOREST GROWTH REDUCTION? 1

2

3

1

Alessandra Bottero* , Daniele Castagneri , Paola Nola , Giorgio Vacchiano , Renzo Motta

1

1

Department of Agriculture, Forest and Food Sciences - University of Torino Department of Land, Environment, Agriculture and Forestry - University of Padua 3 Department of Earth and Environmental Sciences - University of Pavia 2

Drought events have become more frequent in the Mediterranean Basin since the 1970s, and natural forest productivity in the northern portion of the basin shows a declining trend. Among European regions, the Mediterranean Basin could be severely affected by climate change linked to global warming in the 21st century, undergoing drier conditions and an increase in the frequency and duration of extreme drought events. Dendroecology is a valuable tool to describe climate impacts on tree species and forests. It provides information on long-term forest-climate interactions by retrospectively analyzing the response of tree performance to past climatic conditions. This study aims to assess the response of European beech (Fagus sylvatica) forests to present and past climatic changes in northwestern Italy. A network approach will be used, by sampling stands at different elevations and sites, for a better understanding of plant-climate interactions under both geographic and climatic gradients. Analyses will be carried out at different spatial and temporal scales; we will try to understand which are the most important climatic factors for beech tree growth, and whether these factors are stable in time. Short-term (e.g., drought events) and long-term (e.g., management effects) responses of beech to climatic and land-use changes will be assessed. Finally, potential changes in habitat for beech will be assessed by fitting species distribution models under current and future climate. Climatic responses from dendroecology and models will be compared and integrated to provide insights on future trends of beech populations in the study area. Theme: O08. Drought and mortality Presentation Type: Poster INVERTING ECOPHYSIOLOGICAL MODELS TO RECONSTRUCT PAST CLIMATIC VARIATIONS: AN EXAMPLE FROM THE FONTAINEBLEAU FOREST, FRANCE 1

2

3

4

5

Etienne Boucher* , Joel Guiot , Christine Hatte , Pierre-Alain Danis , Valerie Daux , Philippe Dussouillez

6

1

UQAM-GEOTOP, Monteal, Canada CNRS-CEREGE, Europole Mediterraneen de l'Arbois, France 3 LSCE-CEA, Paris, France 4 LSCE, Paris, France 5 IRSTEA, Aix-en-Provence, France 6 CEREGE, Europole Mediterraneen de l'Arbois, France 2

We present the first reconstruction performed from an inverse modeling approach in dendroclimatology. We capitalize on the set of mathematical functions implemented within the MAIDENiso ecophysiological model to account for non-linear, complex, and non-stationary relationships that exist between climate variables (e.g. temperatures, precipitation) and tree growth parameters (tree ring increments and stable isotopes of tree ring cellulose). We exemplify our methodology by reconstructing precipitation and temperature fluctuations over the last 150 years in Fontainebleau, France, using isotopic and tree ring oak chronologies. We compare our reconstructions with conventional regression-based methods and with CRU data. The results presented here suggest that such an inverse modeling approach can produce reconstructions that are at least as good, if not better, then those performed by standard regression analysis. Moreover, inverting mechanistic models has significant advantages over traditional methods. The most important is perhaps their ability to distinguish between CO2 fertilization and climatic effects on tree growth, therefore producing paleoclimatic trends that are exempt of anthropogenic trends. The second advantage is that complex interactions between temperature and precipitation are accounted for directly by the model and thus, the approach holds great promise, especially in the context where tree growth is limited by a combination of multiple factors. Theme: O02. Measuring and modelling wood formation *Indicates presenting author.

17

WorldDendro2014 Accepted Abstracts Presentation Type: Oral OXYGEN ISOTOPIC COMPOSITION IN THE TROPICAL CONIFER AGATHIS ROBUSTA RECORDS ENSO-RELATED PRECIPITATION VARIATIONS 1

2

Bjorn Boysen* , Michael Evans , Patrick Baker

3

1

Department of Sustainability and Environment, East Melbourne, Vic Australia University of Maryland, College Park, MD USA 3 University of Melbourne, Melbourne, Vic Australia 2

Observations related to precipitation variability in northeastern tropical Australia are associated with El NinoSouthern Oscillation (ENSO) activity. We measured tree-ring width and oxygen isotopic composition of alphacellulose from crossdated sections of Agathis robusta collected from Dinden and Danbulla National Parks, tropical Far North Queensland, Australia. Standard ring-width chronologies yielded low internal consistency due to the frequent presence of false ring-like anatomical features. However, in a pilot study of the most recent 15 years of growth (1995-2010), we found significant correlation between oxygen isotopic compositions and local precipitation, the latter associated with ENSO activity. The results are consistent with process-based forward modeling of the oxygen isotopic composition of alpha-cellulose. The oxygen isotopic record also enabled us to confirm the presence of a false growth ring, and determine that it occurred as a consequence of anomalously low rainfall in the middle of the 2004/5 rainy season. The combination of incremental growth and isotopic measures may be a powerful approach to development of long-term (150+ year) ENSO reconstructions from the terrestrial tropics of Australasia. Theme: O01. Tropical dendrochronology Presentation Type: Poster SPATIO-TEMPORAL ANALYSES OF ASIAN SUMMER MONSOON VARIABILITY OVER THE TIBETAN PLATEAU BY A NETWORK OF TREE-RING STABLE OXYGEN ISOTOPE CHRONOLOGIES 1

1

1

1

1

Achim Brauning* , Jussi Griessinger , Christina Dennerlein , Jakob Wernicke , Philipp Hochreuther , Jurgen 2 3 3 3 Bohner , Haifeng Zhu , Liang Eryuan , Lily Wang 1

University Erlangen-Nuremberg, Erlangen, Germany University of Hamburg, Hamburg, Germany 3 Institute of Tibetan Plateau Research, Beijing, China 2

The spatial pattern of stable oxygen composition in current precipitation on the Tibetan plateau mirrors the pathways of air masses from the surrounding oceans into the continent and the amount of rainfall during the summer monsoon season. The oxygen isotope composition in wood cellulose reflects the isotope source value of soil water and is thus an indicator of past hydroclimate. We established a network of twenty stable oxygen isotope chronologies from trees covering the complete eastern Tibetan plateau to analyze the spatial variations of isotope composition of precipitation during the past thirty years. We compare these patterns with present-day isotope distribution in precipitation derived from field measurements and modeling results and interpret the results as a change in the dominant atmospheric circulation patterns bringing monsoon precipitation to the Tibetan plateau. Furthermore, we established a number of multicentury stable isotope chronologies for reconstructing long-term changes in regional hydroclimate. For calibration of tree-ring isotope-climate relationships, we use various sets of climatic data, including modeled data with a high spatial resolution considering modifications of available instrumental and reanalysis data by the extreme topography. Wavelet analyses reveal regional differences in dominant frequency components along a climatic gradient which points to changes in the dominant climatic forcing mechanisms over the Tibetan plateau during the past 800 years. Finally, we discuss the impact of changing hydroclimate on glacier fluctuations triggered by climate variations since the Little Ice Age maximum glacier advance on the eastern Tibetan plateau. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral


18

WorldDendro2014 Accepted Abstracts INTER-ANNUAL VARIABILITY OF TREE-GROWTH PERIODICITY AND PRECIPITATION RECONSTRUCTION IN A TROPICAL DRY FOREST IN ECUADOR 1

1

1

2

2

Achim Brauning* , Susanne Spannl , Darwin Pucha , Oswaldo Ganzhi , Hector Maza , Eduardo Cueva

3

1

University Erlangen-Nuremberg, Erlangen, Germany Universidad Nacional de Loja, Loja, Ecuador 3 Naturaleza y Cultura International, Loja, Ecuador 2

Tropical dry forests host a considerable part of tropical tree biodiversity and strongly contribute to the biomass and carbon sequestration of tropical forest ecosystems. We present high-resolution dendrometer measurements combined with wood anatomical thin sections gained by micro-coring of several tree species from the dry forest ecosystem ‘Laipuna’ in southern Ecuador. Our dendrometer series cover the past six years and document species-specific tree response to the high inter-annual variability of precipitation and length of the growing season that varies between 2-4 months per year. Daily amplitudes of stem diameter variation of Loxopterygium huasango show four distinct periods of stem diameter variations linked to phonological phases I-IV and climate forcing: In the leafless phase I, stem swelling occurs at the onset of the wet season by water uptake without cambial growth to compensate stem shrinkage during the previous dry season; phase II is the period of active growth during the wet season, this period is very variable in length. In phase III, the stems start to shrink after the termination of the wet season. During the dry period (IV), the trees are leafless and stem diameters remain on a plateau of low values. Stable carbon and oxygen isotope analyses of annually formed growth rings show a strong correlation with sea surface temperature variations in the equatorial Pacific and to the El Nino-Southern Oscillation (ENSO) index and thus prove the suitability of tropical tree species to reconstruct large-scale climate patterns. Theme: O01. Tropical dendrochronology Presentation Type: Poster QUANTITATIVE ANATOMY OF CELL PARAMETERS FROM SURFACE IMAGES REVEAL CLIMATIC FORCING ON LATEWOOD FORMATION OF CORSICAN PINE (PINUS NIGRA SSP. LARICIO) 1

1

Achim Brauning* , Timo Hetzer , Hanns Hubert Leuschner

2

1

University Erlangen-Nuremberg, Erlangen, Germany Institute Plant Sciences, University of Gottingen, Germany

2

Numerical cell analysis of wood is constrained by the time-consuming preparation of high-quality microsections. We applied a time-efficient surface preparation technique which allows the production of highquality digital images by fast reflected light microscopy. In addition, a high-efficient data processing and analysis procedure for xylem cell data is presented that allows the quantitative analysis of wood-anatomical features of consecutive series of tree rings. The methods were tested on a dataset of cell dimensions of latewood of Pinus nigra ssp. laricio trees from the upper tree line in Corsica (France). Intra-annual cell profiles of consecutive growth rings were investigated. Lumen area, cell wall thickness, and radial cell width were measured for a period from AD1950-2008. In addition, wood density was modeled based on numerical cell properties. Cellular profiles of latewood formed in climatic extreme years were analyzed by linking climatic variability to intra-annual cell variability. Cell parameter profiles of cell lumen area, cell length and modeled wood density were classified by using multivariate statistics. Linear modeling using climatic variables (monthly mean values of temperature and monthly precipitation sums) revealed a strong climatic influence on intraannual cell variability. The analysis of cell profiles provides a better understanding of the commonly used parameter ‘wood density’ and the climatic forcing of the xylogenesis of intra-annual density fluctuations. Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Poster


19

WorldDendro2014 Accepted Abstracts EL NINO-SOUTHERN OSCILLATION AND RADIAL GROWTH OF CORDIA ALLIODORA IN DRY FORESTS OF COLOMBIA 1

2

Ana Briceno* , Stella Bogino , Orlando Rangel

1

1

National University of Colombia, Bogota¡, Colombia State University of San Luis, Argentina

2

Dry tropical forests covered about 9,955 km2 in Colombia and are of critical ecological, conservational and social interest. Presently, these forest are, in Colombia, the most vulnerable to changing climatic conditions. In this contribution we document the impact of El Nino - Southern Oscillation; which has a drought period (El Nino events) and a wet period (La Nina events) on the growth rings of Cordia alliodora (Ruiz & Pav.). Standard dendrochronological techniques were applied on 12 samples at Guayabal - Armero sampling sites that belong to warm lowland forests in the tropical region of Colombia between 0 and 1000 m asl. Results show a significant correlation between series (0.313). Residual chronologies and El Nino events show a negative association. During wet years or La Nina events (1999, 2008), growth rates were higher than the average of the series. Therefore, the growth dynamic of C. alliodora is sensitive to dry as well as wet years being an accurate tool for dendroclimatological studies in dry tropical forests. Theme: O01. Tropical dendrochronology Presentation Type: Oral PRELIMINARY RESULTS OF DENDROPROVENANCING IN THE EASTERN UNITED STATES Martin Bridge*

1,2

1

Oxford Dendrochronology Laboratory, United Kingdom Institute of Archaeology, University College London, London, UK

2

A large amount of historical data relating to individual sites has been accumulated for several species across a large area of the eastern United States. The inter-relationships between the raw tree-ring width data for these sites will be investigated, giving clues as to what may constitute a good match between sites, and species. Some sites have already given evidence of the sourcing of timber from trees grown at large distances from the end user point, but most are probably of local origin. Dendroprovenancing traditionally uses the strength of a tree-ring match (for example a t-value) as a means of identifying the source area of the trees used. This simple method can be shown to be inadequate at small scales because studies of living trees show that ecologically similar sites at greater distances often give stronger matches than geographically closer sites - although the system works well over greater distances, e.g. for detecting imported timber from the Baltic area into western Europe. This 'arm-chair' exercise will look at the relationships between historic data sets in a different geographical area (USA) to see what may be determined about distance/similarity features. Well-replicated regional chronologies constructed for dating determinations are proving useful in climatic reconstruction, even though this was not their primary purpose. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral XYLEM REPAIR BY WOOD GROWTH DETERMINES TREE RECOVERY RATES AFTER EXPOSURE TO EXTREME WATER STRESS 1

1

Tim Brodribb* , David Bowman , Sylvain Delzon

2

1

University of Tasmania, Hobart, Australia University of Bordeaux, Talance, France

2

Motivated by the urgent need to understand how water stress-induced embolism limits the growth and survival of plants during drought, we examined the linkage between water-stress tolerance and xylem cavitation resistance in one of the world’s most drought resistant conifer genera, Callitris. Four species were *Indicates presenting author.

20

WorldDendro2014 Accepted Abstracts subjected to drought treatments for a period of 3-4 weeks, after which plants were re-watered. Transpiration, basal growth and leaf water potential were monitored during and after drought. Lethal water potential was correlated with the tension producing a 50% loss of stem hydraulic conductivity. The most resilient species suffered minimal embolism and recovered gas exchange within days of re-watering, while the most sensitive species suffered major embolism and recovered very slowly. The rate of repair of water transport in the latter case was equal to the rate of basal area growth, indicating xylem reiteration as the primary means of hydraulic repair. The survival of, and recovery from, water stress in Callitris are accurately predicted by the physiology of the stem water-transport system. As the only apparent means of xylem repair after embolism, basal area growth is a critical part of this equation. Theme: O08. Drought and mortality Presentation Type: Oral DENDROECOLOGICAL CHARACTERISTICS OF PEDUNCULATE OAK (QUERCUS ROBUR L.) AND SESSILE OAK (QUERCUS PETRAEA LIEBL.) IN POLAND 1

Agnieszka Bronisz* , Karol Bronisz

1

1

Warsaw University of Life Sciences, Warszawa, Poland

Pedunculate and sessile oaks are species important from the ecological and economical point of view and are widely used in forest production in Poland. Those species cover 7,5% (535 thousand hectares) of the total forest area of the country. In order to ensure the sustainability of forest ecosystems, each study that contributes to better knowledge of their ecology are considered to be important. The presented study investigates the influence of climate and habitat conditions into oaks radial growth and wood density. Wood density was determined using the blue light intensity and differences in response between two species. Treering widths and blue light intensity were measured using CDendro&CooRecorder (www.cybis.se) software. The dendrochronological package 'dplR' and statistical methods (two-way analysis of variance, stepwise regression analysis and Tukey post-hoc test) were used during analyses. The obtained results indicated that such environmental factors as temperature, precipitation and habitat have a significant impact on tree-ring widths and wood density. Theme: Z01. Other Presentation Type: Poster PRELIMINARY RESULTS FROM AN EMERGING NETWORK OF ALPINE CHRONOLOGIES IN SOUTH-EAST AUSTRALIA 1

1

1

Matthew Brookhouse* , Rochelle Campbell , Camille Couralet , Sarah Goldin

1

1

Australian National University, Canberra, Australia

Recent Australian dendroclimatological studies have placed considerable emphasis upon constructing proxyrainfall and -drought histories. This is understandable iven the limiting role played by precipitation in Australia. However the putative role played by temperature in exacerbating recent droughts demonstrates that longterm temperature variability, especially in south-eastern Australia, also deserves attention. Few dendrochronological sources of multi-centennial proxy-temperature data exist in the Australian region. Until recently none were reported for growing-season temperatures on the Australian mainland. The Australian mainland's only alpine conifer, Podocarpus lawrencei, is of key importance in this regard. The species is long lived (>500yrs) and growth is sensitive to variation in growing season temperature. However, the species' dendroclimatological potential remains only partially explored. In particular, opportunities presented by variables other than width have not been tested. Furthermore, although the species is widespread throughout the Australian Alps, no attempt to develop and test a network of tree-ring chronologies has been reported. In this presentation, I will discuss recent results from the application of the minimum blue-intensity technique and highlight the progress towards, and preliminary results from, an emerging network of P. lawrencei chronologies. As observed elsewhere, the minimum blue-intensity technique has proven to be an effective


21

WorldDendro2014 Accepted Abstracts proxy for growing-season temperature. In addition, application of a principle-component based analysis of the emerging network has generated powerful regional climatological results. Theme: General Session Presentation Type: Oral TREE RINGS, MONSOON CLIMATE AND THE RISE AND FALL OF SOUTHEAST ASIA'S KINGDOMS OVER THE PAST MILLENNIUM 1

2

3

4

Brendan M. Buckley* , Brian Zottoli , S.-Y. Simon Wang , Roland Fletcher , Christophe Pottier

5

1

Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University Postodoctoral Fellow for Transregional Research, Social Science Research Council 3 Utah Climate Center and the Department of Plants, Soils and Climate, Utah State 4 Department of Archaeology, University of Sydney, NWS 2006 Australia 5 Ecole francaise d'Extreme-Orient (EFEO) - Princess Maha Chakri Sirindhorn Anthro 2

Recent interest in the Asian Monsoon and its dynamic evolution has led to significant development of paleoproxies of monsoon strength from tree rings and speleothems. A story has emerged of a variable monsoon over the latter Holocene, with extended droughts and pluvials that occasionally and profoundly influenced the course of human history. We focus on Southeast Asia where an anomalous period of unstable climate coincided with the demise of the capital of the Khmer Empire at Angkor between the 14th and the 16th centuries. Protracted periods of drought and deluge rain events that deleteriously impacted Angkor's extensive water management infrastructure may have prompted the transfer of the political capital away from Angkor. The late 16th and early 17th century experienced climate instability and the collapse of China's Ming Dynasty, and although floods and droughts were experienced from Tonkin to the Bay of Bengal throughout the 17th century, only some were associated with collapse. The latter half of the 18th century was a period of great climatic and societal turmoil across Southeast Asia, when all of the region's polities saw great unrest and rapid realignment during one of the most extended periods of drought of the past millennium, and drought and famine wreaked havoc across India. In this paper we combine proxy data from tree rings with historical documentation to analyze the role that climate extremes may have played in the collapse or disruption of regional societies over the past millennium, a subject of increasing concern under an uncertain future climate. Theme: S02. Civilisations, climate and tree rings Presentation Type: Oral CLIMATIC SENSITIVITY OF TREES IN HIGH BIODIVERSITY FORESTS IN MONGOLIA 1,2

2

3

4

Oyunsanaa Byambasuren* , Baatarbileg Nachin* , Neil Pederson , Johann Georg Goldammer , Michael 5 5 Muehlenberg , Martin Worbes 1

Global Fire Monitoring Center (GFMC), Germany National University of Mongolia, Mongolia 3 Columbia University, USA 4 Global Fire Monitoring Center (GFMC), Germany 5 University of Goettingen, Germany 2

Many climatic factors play a strong role in the growth of trees and dynamics of forest ecosystems. Among these, temperature, precipitation, and snowpack may be among the most important in mountain environments. It is important to understand past and future effects of these individual factors on forest growth and its dynamics. In this study we aim to understand the climatic sensitivity of the most biodiversitydiverse forests in Mongolia, the Khentii Mountains of northern-central Mongolia. Mongolia has experienced significant changes in climate over the last few decades, including rapid warming over the last 30 years and a strong pluvial and two droughts during that same time period. Notably, the most recent drought episode, lasting from the late 1990s to the early 2000s, might have been exacerbated by significant warming over Asia. By examining tree ring records of all dominant tree species from a wide range of sizes and ages in two forest types above 1000 m.a.s.l., we will have significant insight into the sensitivity of this diverse ecosystem to *Indicates presenting author.

22

WorldDendro2014 Accepted Abstracts climatic change. Using tree-ring chronologies of five main tree species, we found that trees display distinct correlation features with climatic variables, although the growth of all species are generally correlated with one another. Among the tree species examined here, Pinus sylvestris was strongly associated with annual stream flow variability, which is a large-scale indicator of moisture availability. Information obtained from this study can expand knowledge about forests growing in such extreme conditions. Our findings will also help guide forest management decisions under changing climate. Theme: General Session Presentation Type: Oral

C MAY-JUNE MEAN TEMPERATURE RECONSTRUCTION INFERRED FROM TREE RINGS IN NORTH CHINA SINCE 1767 AD 1

1,2

Qiufang Cai* , Yu Liu , Hua Tian

1

1

The Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China Jiaotong University, Xi'an, China

2

High-resolution tree-ring records covering the last hundreds years in north China are very scarce, yet essential for understanding the process and pattern of climate change and designing climate model. In the present work, a Chinese pine (Pinus tabulaformis Carr.) ring-width chronology spanning 1767-2008 AD was developed using standard dendroclimatological methods in the Heng Mountains, north China. Strongly negative relationships were detected between the ring-width chronology and the monthly mean temperatures (minimum, mean, and maximum) from April to September during the growing season. Based on correlation analysis, the mean temperature from May to June was reconstructed back to 1767 AD. Both spatial correlation analysis with CRU grid dataset and comparisons with other tree-ring based temperature reconstructions from surrounding areas revealed that this reconstruction represented a larger-scale regional temperature variation for north-central China. Significant spectral peaks were found at 2.04-, 2.05-, 2.22-, 7.69-, 75- and 100- year, implying the possible influence of ENSO and solar activity on the local climate. Considering the strong and negative relationship between tree growth and temperature, the future warming will possibly bring increasing drought stress for the tree growth, as shown by the recent warming since the 1950s. However, due to the limit of tree age, this reconstruction did not capture the multi-century scale variations which presents the necessity for developing more and longer tree-ring chronologies in the future in north-central China. Theme: General Session Presentation Type: Oral QUANTITATIVE WOOD ANATOMY IN MULTI-CENTURY NORWAY SPRUCE CHRONOLOGIES. NEW METHODS AND PROMISING RESULTS 1

1

Daniele Castagneri* , Giai Petit , Marco Carrer

1

1

Dept. TESAF, Universita di Padova, Legnaro (PD), Italy

For several decades, dendrochronologists have analyzed tree ring widths to assess climate effect on tree growth. Thanks to technology improvements, today it is possible to look at the elements that compose the ring, i.e. to quantitatively analyze wood cells and to investigate what influences their characteristics. We built multi-century tracheid size chronologies of Norway spruce to test whether cell features provide stable and valuable information on the tree response to climate. Increment cores were collected in three sites at 1200, 1600 and 2000 m a.s.l. at Croda da Lago, Eastern Italian Alps. Thin sections were cut with a rotary microtome, stained with safranin and observed under the microscope at 40X. Images were processed with Roxas software to calculate parameters of size distribution from hundreds to thousands of cells for each ring. Using daily records of temperature and precipitations from a nearby weather station, tree response to climate was


23

WorldDendro2014 Accepted Abstracts assessed for different time windows over 80 years. Response to monthly climate has been assessed over a longer time span. At high elevation, ring width was more affected by summer temperature, while cell size was more influenced by previous winter and spring climate. At intermediate and low elevation, cell size was negatively affected by warm and dry summers, while ring width was not. Quantitative wood anatomy in conifer can increase our understanding on climate effect on trees, and with new methodologies such relationships can be analyzed over long time periods. Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Oral DENDROCLIMATIC INTERPRETATION OF TREE-RING WIDTH OF SORBUS TORMINALIS FROM NORTH PART OF POLAND 1

Anna Cedro* 1

Szczecin University, Szczecin, Poland

Wild service tree (Sorbus torminalis L. Crantz.) is non-dominant sub-canopy and rare tree species in Polish forests, occurring in deciduous and mixed forests. The study area covers north-western part of Poland, representing the eastern distribution limit of the species. Actually, Sorbus torminalis is a protected species in the whole area of Poland, but still it is found in small fragmented populations consisting of 3-few hundred individuals. In this study dendrochronology methods are used to find the age of trees, effects of climate (air temperature, precipitation and insolation) and habitat conditions. More than 120 trees from natural reserves and forest plantations were sampled for analyses. The wood of Wild service tree is hard, diffuse porous and tree-ring annual increases are poorly distinguished. The measurements of widths of annual growth rings and dendroclimatological analyses (response function and pointer years) were carried out in the Dendroclimatological Laboratory at Szczecin University. Wide growths of Sorbus torminalis are stimulated by abundant precipitation during previous and actual vegetation season. High values of multiple regression (r2) indicate significant relationships between weather conditions and annual growth rings at this species. Theme: Z01. Other Presentation Type: Poster THE POTENTIAL OF DENDROCHRONOLOGY FOR TREE GROWTH AND YIELD STUDIES IN MOZAMBIQUE 1

1

Esperanca Chamba* , Jacob Bila , Elias Secretario

1

1

Agrarian Research Institute of Mozambique, Maputo, Mozambique

Mozambique is a country endowed with vast forest resources, a source of livelihood of 80% of the population living in rural areas. About 54 millions of the country is covered by forests and other vegetation types from which 51% are classified as forests. The predominant ecoregions are Miombo and Mopane proving the majority of wood species for domestic use and export. The sustainable management of this resource base for the economy and livelihood of Mozambique population is becoming increasingly important with the growing demand on forest products and services. Climatic variability poses an additional pressure into forest resources since it affects their growth and productivity. Thus, scientific information regarding growth, yields and dynamic of forests are crucial. In the last 10 years, growth and yield studies through the establishment of permanent sampling plots (PSP) are conducted. These are long term studies and the monitoring of extreme climatic events and variability on the forest is not easy. Dendrochronolgy is a useful complement to PSP since it gives faster and reliable results. Some initial studies on dendrochronolgy were done in Mozambique with encouraging results. This research aims at study the growth and yield patterns of three species used for timber and one for fuel wood in the south of Mozambique. Destructive and non-destructive methods are used for sampling. It is expected that the results will contribute to design sound polices that leads to a sustainable management of forest ecosystems in Mozambique. Theme: O01. Tropical dendrochronology Presentation Type: Poster *Indicates presenting author.

24

WorldDendro2014 Accepted Abstracts WARM-SEASON TEMPERATURE - MAY-AUGUST - VARIABILITY FOR THE NORTHERN XINJIANG AND TIANSHAN MOUNTAIN AREAS INFERRED FROM MULTI-SITE TREE-RING DENSITY CHRONOLOGIES 1

1

1

1

1

1

Feng Chen* , Yujiang Yuan , Wenshou Wei , Huaming Shang , Tongwen Zhang , Ruibo Zhang , Huiqin Wang

1

1

Institute of Desert Meteorology, China Meteorological Administration, Urumqi

Tree-ring density chronologies from five sites in the northern Xinjiang and Tianshan Mountain areas were analyzed for regional common climate information using principal component analysis and arithmetic average method. The first principal component accounts for 40.88% of the total variances of the five site density chronologies, and high correlated with the arithmetic average values of the five site density chronologies. The arithmetic average value of the five site density chronologies was highly positively correlated with the MayAugust mean temperature averaged from thirty-three meteorological stations in the northern Xinjiang and Tianshan mountain areas. The climate/tree-growth model accounts for 44.5% of the temperature variance from 1960 to 2008. Warm conditions prevailed during AD 1656-1664, 1667-1692, 1711-1734, 1804-1832, 1855-1956 and 2000-2008. Several severely cold warm seasons coincide with major volcanic eruptions. Some of the temperature variations also correspond to variations in solar activity. The low-frequency change of temperature reconstruction is correlated positively with Northern Hemisphere temperatures. Our reconstructed temperature is significantly correlated with sea-surface temperature (SST) in the tropical Atlantic Ocean (positive), the North Pacific Ocean (positive) and the North Atlantic Ocean (positive). The spatial correlation patterns between our temperature reconstruction and SSTs of the Atlantic and Pacific Oceans, cloud cover, and volcanic eruptions suggest a connection between regional temperature variations and the high-mid latitude northern atmospheric circulations (Westerlies). Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral INFLUENCE OF DETRENDING METHODS ON VARIABILITY OF TEMPERATURE SIGNAL IN DIFFERENT TIMESCALES INFERRED FROM TREE RINGS 1

1

1

1

1

2

Xin Chen* , Pei Xing* , Yong Luo* , Jianbin Huang* , Zongci Zhao* , Shaowu Wang* 1

Center for Earth System Science, Tsinghua University, Beijing, China Department of Atmospheric Sciences, School of Physics, Peking University, Beijin

2

East Asian monsoonal rainfall has had drastic impacts on vast regions over recent decades. Longer records and insight into temporal rainfall patterns could aid greatly in anticipating extreme events and agrarian planning. The area of Northeast China is representative of the northeastern Asian region, and tree-ring resources are used to extend the climate record and test for Pacific Ocean teleconnections. We present herein several wellverified precipitation reconstructions (r=0.550~ 0.610, p 100 years old. No relationship with precipitation was found. Apart from short precipitation series, this missing link could be caused by the limited number of stem disks or the lack of growth response to local climate conditions as expressed by monthly precipitation values. Both causes are commonly met problems in the tropics and in response, we illustrate and recommend the use of bootstrapping to, e.g., verify how representative a sample is, and the use of large-scale long-term climate variables as sea surface temperatures and El Niñoindices to analyse their link with tropical tree-ring indices or annual density values. The described methodology is demonstrated for Pericopsis but has potential for all tree species with annual tree-ring formation. Theme: O01. Tropical dendrochronology Presentation Type: Oral TREE-RING ANALYSIS AND STEM BIOMASS ESTIMATION OF TERMINALIA SUPERBA ENGL. & DIELS IN THE FRAMEWORK OF SUSTAINABLE FOREST MANAGEMENT 1

2

1

Maaike De Ridder* , Jan Van den Bulcke , Hans Beeckman , Joris Van Acker

2

1

Royal Museum for Central Africa, Tervuren, Belgium Ghent University, Ghent, Belgium

2

Sustainable forest management depends on the availability of quantitative data, often not available in African rainforests. Tree-ring observations and detailed information on wood density of Terminalia superba Engl. & Diels, a long-lived pioneer species, enabled the collection of these data. Planted and natural forest trees were sampled in Ivory Coast and in the Mayombe Forest in the Democratic Republic of Congo. In both study regions, tree rings are annual and appear related to the El Niño-Southern Oscillation. A clear link with local precipitation patterns is only found in the Mayombe Forest. Growth curves also offer the opportunity to calculate growth-based variables for sustained yield, variables that appeared site-specific. Next, a study on growth changes revealed that T. superba generally reaches the canopy without releases or suppressions, validating that this species does not need intensive silvicultural management. Combining annual tree-ring data and pith-to-bark wood density profiles, directly measured by state-of-the-art X-ray scans, enables the extraction of annual wood densities. Wood density annually increases from pith to bark and allows for detailed estimates of carbon stocks over time. The assumed overestimation of carbon stocks in tropical Africa was confirmed and related to the use of fixed instead of annual wood densities. This example confirms the huge potential of tree-ring analysis and detailed wood density data for long-term planning of sustainable forest management and carbon stocks. Both methods can be used complementary to inventories, combining the diversity of inventory variables with tree rings that extend decades to centuries into time. Theme: O01. Tropical dendrochronology Presentation Type: Poster


30

WorldDendro2014 Accepted Abstracts DHXCT: THE USE OF HELICAL X-RAY CT IN DENDRO-RESEARCH 1

2

3

3

3

3

Jan Van den Bulcke , Erik L.G. Wernersson , Manuel Dierick , Denis Van Loo , Bert Masschaele , Loes Brabant , 3 3 4 5 5 5 Matthieu N. Boone , Luc Van Hoorebeke , Kristof Haneca , Maaike De Ridder* , Hans Beeckman , Agathe Die , 2 2 1 Anders Brun , Cris L. Luengo Hendriks , Joris Van Acker 1

UGCT - Ghent University, Dept. of Forest and Water Management, Laboratory of Wood Technology, Coupure Links 653, 9000 Ghent, Belgium 2 Swedish University of Agricultural Sciences, Centre for Image Analysis, Box 337, SE-751 05 Uppsala, Sweden 3 UGCT - Ghent University, Department of Physics and Astronomy, Proeftuinstraat 86, 9000 Ghent, Belgium 4 Flanders Heritage Agency, Koning Albert II-laan 19, bus 5, 1210 Brussels, Belgium 5 Royal Museum for Central Africa, Laboratory for Wood Biology and Xylarium, Tervuren, Belgium X-ray Computed Tomography (XCT) has become a well-established technique in many fields of science. Its application in wood research is also increasing considerably. Thanks to the non-destructive nature of the imaging process as well as the internal view on the three-dimensional structure, it is one of the pre-eminent techniques for multi-scale studies of wood. With standard cone-beam tomography, however, long samples with limited cross-sectional dimensions are hard to scan at high resolution. Stacked scanning and volume stitching are necessary for such samples. Tree-ring research mainly uses increment cores or generally speaking pith-to-bark trajectories which are typically long but with rather small cross-sectional dimensions. Such samples, therefore, could benefit from other acquisition routines, such as the helical scanning protocol. The sample is not only rotated 360° but is also moved along the z-axis, resulting in a helical movement. We will show how helical X-CT (HXCT) can be of use in tree-ring research, giving examples of its use on oak (Quercus spp.), limba (Terminalia superba) and teak (Tectona grandis). Custom-made sample holders enable scanning of several pith-to-bark trajectories sawn from wood disks simultaneously. Reconstructed volumes can be converted to absolute densities without classical time-consuming calibration methods and density profiles can be obtained. Furthermore, the 3D volume can also be used for accurate ring width measurements taking into account ring and grain angle. In some cases, quantitative wood anatomical measurements are also feasible. Finally, dedicated scans at higher resolution can resolve finer anatomical details. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral HOLOCENE WATER AVAILABILITY IN THE NORTHERN ATACAMA DESERT AS RECORDED BY OXYGEN ISOTOPE VARIATIONS IN PROSOPIS TAMARUGO 1

1

Justin Dodd* , Elizabeth Olson , Mario Rivera

2

1

Dept. of Geology, Northern Illinois University, DeKalb, USA Dept. of Anthropology, Beloit College, Beloit, USA

2

The Atacama Desert in northern Chile is one of the driest regions on Earth. As a result, water availability in the Atacama is primarily driven by water transport/recharge from higher altitudes in the Andean Mountains. Here we present multiple sub-annually resolved time-series of oxygen isotope values from ancient and modern Prosopis tamarugo tree ring δ±-cellulose. These data provide a novel record of regional variations in water availability in the northern Atacama. Oxygen isotope values in the P. tamarugo samples record significant variability in regional climate and hydrology throughout the past 9 ka. Ancient (9.1 to 4.5 ka) P. tamarugo samples from the Pampa del Tamarugal region of the Atacama record δ18O values that range from 23.8 to 32.8° with relatively high intra-ring variability (3.0°, 2Ïƒ=1.1°). Ramaditas, an archeological site in the region, contains stumps and logs that have a larger range of δ18O values (17.5 to 35.6°) and greater intra-ring variability (ave. 4.5°, 2Ïƒ=3.2°). The greater range in interannual and intra-ring δ18O values most likely reflects a period with highly variable fluxes of runoff/recharge water. Modern P. tamarugo samples collected from recently cut stumps have consistently higher δ18O values (33.1 to 36.3°) with low intra-ring variability (1.5°, 2Ïƒ=0.9°), indicating persistently dry conditions and high evaporation. Sub-annual variations in the δ18O values of P. tamarugo record periods of increased water availability from 9 to 7 ka and at ~4 ka, with persistently drier conditions from ~2.5 ka to present.


31

WorldDendro2014 Accepted Abstracts Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral PLANT ANATOMICAL CHARACTERS AND THEIR VARIATION ALONG ENVIRONMENTAL GRADIENTS: A KEY TO UNDERSTANDING PLANT EVOLUTION, ADAPTATION AND FUNCTION 1

2

1

1

Jiri Dolezal* , Fritz Schweingruber* , Pavel Riha* , Zuzana Chlumska , Jan Altman

1

1

Institute of Botany, Trebon, Czech Republic Swiss Federal Research Institute WSL, Birmensdorf, Switzerland

2

The detailed knowledge of anatomical variation among plants is a key to understanding their evolution and function. Observed variation in anatomical structure is a result of several forces such as 1) adaptation of species to prevailing conditions in their habitat, 2) phenotypic plasticity as an ability of individuals with an identical genotype to develop differently, based on speciï¬c conditions during their ontogeny, and 3) evolutionary constraints in which taxa that share part of their evolutionary history possess similar blue-prints. Understanding the evolution of plant structures require, therefore, separation of evolutionary inertia from a true adaptation to the environment. In our presentation, we provide new insights into anatomical variation for one of the largest dataset of anatomical traits (structure of fibres, vessesls, parenchyma, rays, crystals, bark, annual rings, growth rate and age) in herbaceous plants to link this infomation with their phylogeny and ecology. To understand the evolution of anatomical diversity, we reconstruct the phylogeny of studied taxa from parsimony analysis of nucleotide sequences using the Bayesian inference, and examine the distribution of anatomical characters on the resulting phylogenetic tree. The studied species cover major environmental gradients from subtropic to arctic and high-altitude zones, allowing us to test several hypotheses on evolution of plant structure and function in relation to life-form and ecological preferences. The results show that, despite clear phylogenetic inertia in the anatomical features studied, several important links between these traits and competitive abilities and habitat preferences were found after removing effects of phylogenetic relatedness. Theme: General Session Presentation Type: Oral ALTITUDINAL CHANGES IN FOREST COMPOSITION, STRUCTURE AND WOOD DENSITY ON MT. CAMEROON, WESTERN AFRICA 1,2

1,2

1

3

Jiri Dolezal* , Jan Altman , Martin Dancak , Miroslav Svoboda , Fritz Schweingruber

4

1

Department of Functional Ecology, Institute of Botany, Czech Academy of Sciences, Dukelská 135, CZ-379 82 Trebon, Czech Republic. 2 Department of Botany, Faculty of Science, University of South Bohemia, Na Zlaté Stoce 1, 370 05 Ceské Budejovice, Czech Republic. 3 Czech University of Life Science, Faculty of Forestry & Wood Science, Prague 16521 6, Czech Republic. 4 Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland Tropical forests of Western Africa has been identified as a biodiversity 'hotspot' for both extraordinary species diversity and exceptional concentration of endemic species. However, most of the primary vegetation has been destroyed. It is estimated that 96% of the original montane forests in western Cameroon may have been lost. The largest block of surviving forests is found on Mt. Cameroon (4095m). Here is the most complete representation of the Afromontane flora west of the Congo basin. We explored the changes in the tree community composition along the whole altitudinal gradient from the treeline down to lowland tropical forests (2250-300 m a.s.l.). To characterise the quality of individual forests, the 96 circle plots with 40 m in diameter were established at six elevations. In each plot, all trees more than 10 cm in diameter at breast height (DBH) were mapped, identified to species, and DHB and tree height measured. Because of seasonal rainfall distribution with dry period from November to February some trees have visible tree rings. In each plot 10-15 trees were cored to possibly age the trees, measure wood density and anatomy. Multivariate and regression analyses were used to determine the variability in tree species composition, and to analyze the relationships between species dominance, competitive status (tree height) and wood density characteristics. *Indicates presenting author.

32

WorldDendro2014 Accepted Abstracts Finding interconnections between species-dominance curves and wood density patterns provide new insight into mechanisms structuring forests from low to high elevations. Theme: O01. Tropical dendrochronology Presentation Type: Poster THE POSSIBILITIES AND LIMITATIONS OF TREE-RING DATA FOR GLACIER MASS-BALANCE RECONSTRUCTIONS IN CENTRAL CAUCASUS 1

1

Ekaterina Dolgova* , Irina Bushueva , Vladimir Matskovsky

1

1

Institute Of Geography RAS, Moscow, Russia

The main goal of the study is tree-ring based reconstruction of mass-balance of the representative glaciers in the Caucasus Mountains for the period exceeded instrumental records. Ring-width and maximum density from more than 10 tree-ring sites of Scots pine (Pinus sylvestris L.) and Nordmann fir (Abies Nordmanniana) were used here. It was found that ring-width formation controlled by both temperature and precipitation of the current and preceding years to growth. While maximum density strongly represents warm period air temperatures of the current year. Since modern glacier retreat is controlled by increased summer temperatures only maximum density chronologies has significant correlation with mass-balance series. To include in our reconstructions different climatically sensitive parameters stepwise multiple regression was used. Cross-validation test confirmed model adequacy and according to EPS the length of mass-balance reconstructions reach 300 years. Our reconstructions were compared with reconstructions based on meteorological data that available for the same glaciers. Most likely the main reason of the discrepancies between series is uneven distribution of the precipitation on the weather stations used for models. In general our reconstructions correspond well with the other proxy data. Thus it shows mass balance increase in 1830 and 1860ss. when equilibrium line was lower 150 m than in the end of XX century. Glacier advance in the middle of XIX century documented well by Abich (1875) who sketched how glacier B. Azau invaded to mature pine forest and filled whole valley. According to Deshy’s photographs made later in 1874-1876 ss. Glacier has started to retreat. Theme: O07. Dendrogeomorphology Presentation Type: Oral 800 YEARS OF RECONSTRUCTED AND SIMULATED SUMMER TEMPERATURE VARIATIONS IN THE SOUTH OF THE IBERIAN PENINSULA 1,2,3

4

5

Isabel Dorado Linan* , Eduardo Zorita , Jesus Fidel González Rouco , Laia Andreu Hayles, Elena Munta¡n 3 2 3 Bordás , Filipe Campello, Ingo Heinrich , Emilia Gutierrez 1

Technische Universitat Munchen. Chair of Ecoclimatology. Munchen. Germany. GFZ. Potsdam DendroLab. Climate Dynamics and Landscape Evolution. Potsdam,German 3 Universitat de Barcelona. Departament de Ecologia. Barcelona,Spain. 4 Helmholtz-Zentrum-Geesthacht, Geesthacht, Germany. 5 Universidad Complutense de Madrid. Ciudad Universitaria. Madrid, Spain. 6 Tree-Ring Laboratory. Lamont-Doherty Earth Observatory of Columbia University. P 7 Departamento de Ciencias da Vida. Centro de Ecologia Funcional. Universidad de C 2

July-to-October temperature variations in the Cazorla Range (Spain) for the last 800 years are reconstructed based on tree-ring widths. The resulting reconstruction (NCZTjaso) represents the southernmost annually resolved temperature record based on tree-rings in Europe and provides detailed information on the regional climate evolution during the Late Holocene in the southeast of the Iberian Peninsula. NCZTjaso is compared to ensembles of climate simulations conducted with (1) two global atmosphere-ocean general circulation climate models (GCM) considering different external forcing: ECHO-G (Erik) and MPI-ESM (E1 and E2); (2) individual simulations from GCM included in the fifth Coupled Model Intercomparison Project; and (3) single-forcing simulations of volcanism (VF), Land Cover changes (LCC), Total Solar Irradiance (TSI) and concentration of greenhouse gases (GG) performed with MPI-EMS. NCZTjaso reveals predominantly warm summer *Indicates presenting author.

33

WorldDendro2014 Accepted Abstracts temperatures from the 13th to middle of the 16th century. The Little Ice Age spanned a slightly longer time (1500-1930CE) than in other European summer temperature reconstructions from the Alps and Pyrenees. The 20th century, though warmer than the preceding centuries, does not show unprecedented warmth compared to the last 800 years. A persistent anti-correlation at multidecadal scales between NCZTjaso and simulations exists during the 1200-1500CE. Reconstructed and simulated temperatures revealed a close agreement of NCZTjaso with the simulations performed with TSI forcing with wider variations. Furthermore, VF shows up as the main factor controlling temperature variations for the last 5 centuries at decadal to multi-decadal timescales. TSI, LCC and GG do not seem to exert a significant influence on tree-growth. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral AUSTRALIAN WOOD FORMATION RESEARCH AND MODELLING: PAST, PRESENT, FUTURE 1

2

Geoff Downes* , David Drew 1

Forest Quality Pty. Ltd, Huonville, Tasmania, Australia CSIRO Ecosystem Sciences, Sandy Bay, Tasmania, Australia

2

Australian researchers have made significant contributions to wood research in many areas. From detailed studies of cell wall ultrastructure, research on wood physics and origin of growth stresses to the development of technology to generate detailed information on wood variation. Much of this has direct application to dendrochronology and climatology to better inform the development of more accurate chronologies and the inferences drawn from them about past climate variation. The application of technologies that measure growth and wood variation, as well as the mathematical expression of cambial biology to predict wood variation have been particularly relevant. Recent research in Tasmania and China has demonstrated the potential, using SilviScan, to interpret decadal-long climate variation within the context of variability in key wood properties. These studies show the opportunity to better explore historical climate variability in geographic regions that have a relative dearth of data. Similarly growth and wood formation models, based on tree biology, are providing tools that allow site, species and climate interactions to better explain how climate interacts with biology to generate ring width variation. These models enable a more robust understanding of tree-ring-based climate proxies and minimize the risk of drawing wrong conclusions. This paper attempts to review the Australian research contribution and identify where further research can provide opportunities that will improve our understanding of wood formation and its relation to climate. Theme: O02. Measuring and modelling wood formation Presentation Type: Oral THE DYNAMICS OF ANNUAL RING FORMATION IN HUON PINE AND OTHER TASMANIAN ENDEMIC CONIFERS 1

David Drew* , Geoffrey Downes

2

1

CSIRO Ecosystem Sciences Forest Quality

2

Annual growth ring widths and wood properties from a number of Tasmanian endemic conifers, including Huon pine (Lagarostrobos franklinii), have been used, or have been shown to have potential to be used, for long-term climate reconstruction. There has been virtually no research done in Tasmania, however, to understand in detail the tree growth responses to environmental conditions that lead to these observed significant climate vs. ring width/wood property correlations. We report here on research undertaken for the last four years (since 2009) involving the detailed (hourly) monitoring of stem radial growth at two contrasting sites (both comprising Huon pine and Celery top pine, Phyllocladus aspleniifolius) in western Tasmania. We show that the timing of the growing season can vary widely between years (by as much as 3 months), and that there can also be differences of several weeks in the timing of annual growth cessation between years. We discuss how the duration of the growing season, in concert with the periodicity and rates of growth during the season, as affected by variable environmental conditions, interact to lead to produce narrow, or wide rings, or


34

WorldDendro2014 Accepted Abstracts variations in wood properties (e.g. latewood density). We also discuss the implications for using wood properties as a powerful proxy for extracting late-season climate information, even when growth has stopped. Theme: O02. Measuring and modelling wood formation Presentation Type: Oral TREE-RING DENSITY RECORDED WARM-SEASON TEMPERATURE VARIATION IN THE SOUTHEASTERN TIBETAN PLATEAU AND LTS LINKAGE WITH EXTERNAL FORCING 1

Jianping Duan* 1

Institute of Botany, Chinese Academy of Sciences, Beijing, China

Recent climate warming in the Tibetan Plateau has been identified by many studies. However, the knowledge of the long-term context and the dominant driving force for such warming is limited due to the complex topography and spatially heterogeneous temperature variability. In this study, we present a 449-year warmseason (April-September) temperature reconstruction based on tree-ring maximum latewood density (MXD) of Balfour spruce (Picea likiangensis var. balfouriana) in the southeastern Tibetan plateau. The MXD chronology explains 57% of the instrumental temperature variance during the period 1961-2011. The reconstruction shows anomalous warming since the 1900s, especially for the last 30 years which corresponded to the strengthened solar irradiance and weakened cosmic ray. Moreover, the reconstructed warm-season temperature series correlated significantly with the solar irradiance (r1715-2000=0.229, p 1000 mm annually) suggests that groundwater could drive growth in many woody ecosystems with sandy soils where DTGW is within 1 to 4 metres of the surface. Theme: General Session Presentation Type: Oral

G THE CAPABILITIES OF ITRAX CORE SCANNER FOR THE CHEMICAL ANALYSIS OF DIFFERENT TREE SPECIES. 1

1

Patricia Gadd* , Henk Heijnis* 1

Institute For Environmental Research, ANSTO, Australia

ITRAX X-Ray Fluorescence (XRF) core scanner is becoming increasingly popular to determine the elemental profile in the growth ring of trees.Temperate treesoften have an advantage of having distinct rings which can be used to extract temporal information. The core scanner produces high resolution optical image,an Xradiograph image and XRF measurements for the surface of the wood. The images provide density information and are useful in determining the obscure annual rings that are typical of many tropical trees. A wide range of elements can be detected using XRF with calcium (Ca) and strontium (Sr) proving to be reliable rainfall proxies that couldbe usedto determine false rings and to complement the standardtechniques of dendrochronology in species in which annual ringsare not always clearly defined. Other elements from industrial pollution such as As Cu, Ni, Pb and Zn can also be detected. The capabilities of the ITRAX core scanner will be presented and several case studies on Australian tree species will be shown to demonstrate some of the work currently being undertaken at ANSTO in collaboration with researchers from variousorganisations and universities. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Poster MODELLING GROWTH OF A MEDITERRANEAN MIXED OAK-PINE STAND USING MULTIPROXY DATA AND A MECHANISTIC APPROACH 1

2

Guillermo Gea-Izquierdo* , Frederic Guibal , Joel Guiot


1

44


CEREGE-CNRS, Aix-en-Provence, France IMBE-CNRS, Aix-en-Provence, France

2

The growth response to climate has long been proved to be often non-stationary and non-linear. Determining the factors originating divergence from the traditionally assumed linear and stationary relationship between growth and climate has much importance in dendroecological and dendroclimatological applications. Additionally forests can be threatened by climate change, particularly drought enhancement. Therefore it is crucial to properly assess how different biotic and abiotic factors interact with climate to determine temporal instability in forest productivity in response to climatic changes and, ultimately, plant vulnerability. To better understand forest performance in a changing environment it is important to use process-based models which can take into account the different factors affecting plants and their response to climate variability. In this study we analyzed growth variability within a mixed Quercus ilex-Pinus halepensis stand in Southern France using the mechanistic model MAIDEN calibrated to a combination of data proxies at different time scales, including tree-rings, carbon flux and transpiration data. Forest performance is analyzed using this model run under different climatic scenarios reflecting an ongoing enhancement in regional overall water stress. We discuss whether future growth projections suggest vulnerability to enhanced water stress and run sensitivity analysis to assess the influence of different abiotic factors on growth instability. Particular emphasis is put to analyze the net effect that the relationship between drought and CO2 increase will have in future growth of the studied Mediterranean stand. Theme: O02. Measuring and modelling wood formation Presentation Type: Poster NON-LINEAR CLIMATE-GROWTH MODELS SUGGEST VULNERABILITY OF MEDITERRANEAN OAKS WITH RISING TEMPERATURES 1

2

2

Guillermo Gea-Izquierdo* , Laura Ferna¡ndez-de-Una , Isabel Canellas 1

CEREGE-CNRS, Aix-en-Provence, France INIA-CIFOR. Madrid, Spain

2

Growth projections using models fitted to tree-ring data collected along climatic gradients can help to understand how forests will respond to climate change. The climate-growth response is known to be nonstationary and non-linear, thus it is important to develop new dendroecological approaches to overcome classic linear models. Stem growth of two Mediterranean oaks was predicted using novel nonlinear multiplicative models as a function of precipitation and minimum temperature of the hydrological year. Growth of both species increased with accumulated precipitation before reaching an asymptote but the species with a warmer niche required lower levels of precipitation to achieve high relative growth. The species-specific relationship between growth and temperature exhibited an optimum for the two species. Trees were negatively affected by high temperatures whereas they responded negatively or neutrally to low annual temperatures after species-specific thresholds. The more drought tolerant Quercus ilex might profit from warming temperatures at cold northern locations but growth projections of both species suggest a future local decrease in productivity at species-specific xeric locations as a result of the expected increase in temperatures without a paired increase in precipitation. This means that deciduous Quercus pyrenaica could be threatened by climate change at the species local dry edge. Stem growth was successfully modeled using biologically meaningful species-specific responses to climate which provided key ecological information to understand the functional response of two species. The models used have much potential to be applied with dendroecological data to study the response of forests to climate change. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral DROUGHT INDUCED NEGATIVE GROWTH TRENDS PORTEND PINE MORTALITY AT XERIC MANAGED MEDITERRANEAN PINE-OAK WOODLANDS 1

2

2

Guillermo Gea-Izquierdo* , Bárbara Viguera , Isabel Canellas *Indicates presenting author.

45


CEREGE-CNRS, Aix-en-Provence, France INIA-CIFOR. Madrid, Spain

2

It is important to understand how different biotic and abiotic factors interact to determine tree mortality and implement predictive models of forest mortality under future scenarios of enhanced xericity. We studied whether rising water stress determined the health status of healthy, weakened and dead Quercus pyrenaica Willd. and Pinus sylvestris L. trees sampled along an elevation gradient and used ordinal logistic regression to model tree susceptibility to decline in relation to stand competition and individual growth-patterns. The mortality pattern differed with local site conditions at different elevations. Pine growth was faster but life-span shorter at more xeric low-elevations than at colder high-elevations. Within stands, healthy trees exhibited less disturbance events and higher growth-rates but not as a consequence of lower tree-tree competition, which under present stand conditions did not increase adult mortality risk. Q. pyrenaica was more sensitive to low moisture variability in the high-frequency response but P. sylvestris expressed less tolerance to drought. Water stress intensity limited tree-growth in the long-term particularly at low-elevations, where growth of dead trees from both species declined with rising water stress after the 1970s. For pines, widespread symptoms of crown decline were only observed at low-elevation stands where, in opposition to oaks, live pines also exhibited recent negative growth-trends similar to those in dead trees. The abundant crown decline symptoms and the pervasive growth decline observed in pines from all health status at the species current local low-elevation xeric limit suggests vulnerability and could portend widespread stand mortality in the studied region. Theme: O08. Drought and mortality Presentation Type: Poster DETECTING CLIMATE VARIABILITY AND ITS IMPACTS USING TREE RINGS IN SUB-SAHARAN AFRICA Aster Gebrekirstos*

1

1

World Agroforestry Centre, Nairobi, Kenya

This study examines responses of tropical tree species to climate variability, and discusses the potential use of tree rings for understanding the drivers and impacts of climate change in sub-Saharan Africa and their ability to reconstruct past regional climate variability and climatic trends. Our approach considers large scale climate gradients and different temporal scales (inter-annual and intra-annual variations) and combines multiparameter measurements (ring width, carbon and oxygen isotopes, whole wood and cellulose measurements). The study species are Faidherbia albida and Sclerocarya birrea from Malawi and Burkina Faso, respectively. Both are very important deciduous trees, and widely distributed in sub-Saharan Africa. Particularly, F. albida has a distinctive phenology; it bears leaves and flowers during the dry season and sheds its leaves during the rainy season. Due to its reverse phenology and high nitrogen fixing ability the species is commonly used and promoted in agroforestry. We hypothesize that tree rings and stable isotopes can help to understand the species unique physiology and unravel if there are external factors triggering its reverse phenology. Both tree rings and stable isotopes showed strong climatic signals including the long Sahel drought events and climatic recovery phases. Theme: O01. Tropical dendrochronology Presentation Type: Oral EVIDENCE FOR WIDESPREAD MIXED-SEVERITY FIRE REGIMES IN WESTERN CANADA 1

2

2

1

2

1

Ze'ev Gedalof* , Raphael Chavardes , Lori Daniels , Eric DaSilva , Theresa Dinh , Helene Marcoux , 'Nez' 1 3 1 Nesbitt , Michael Pisaric , Vanessa Stretch 1

CEDaR Lab, Department of Geography, University of Guelph, Guelph, ON Canada Tree Ring Lab, University of British Columbia, Vancouver, BC, Canada 3 Department of Geography, Brock University, St. Catherines, ON Canada 2


46

WorldDendro2014 Accepted Abstracts Forests characterized by mixed-severity fire regimes are poorly understood, and often unrecognized, yet they are responsible for producing the most complex forest structures and compositions at both the stand and landscape scales. Here we describe two ways that the modern fire record is biased against preserving records of mixed-severity fire, that we argue has led to the importance of mixed-severity fire regimes being underappreciated in much of Western Canada and probably elsewhere. We have developed a hybrid fire history method that relies on both cohort detection and fire scar analysis, fixed radius search areas, and randomly selected plots, that largely overcomes the challenges posed by these biases. Application of these methods in many forest types throughout the western Canadian Cordillera shows that mixed severity fires were much more widespread than has been historically appreciated. Additionally, the effects of fire exclusion over the past century have, in many locations nearly eliminated the visible evidence of the low-severity fire component of mixed severity fires. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral PDO-REDUX: REFLECTIONS ON THE PDO AT THE AGE OF 18 1

Ze'ev Gedalof* , Daniel Vimont

2

1

CEDaR Lab, Department of Geography, University of Guelph, Guelph, ON Canada Department of Atmospheric and Oceanic Sciences, University of Wisconsin, WI, USA

2

The Pacific Decadal Oscillation (PDO) was first recognized as an important mode of variability in the Earth's ocean-atmosphere system in 1996. Since then a number of explanations have been proposed to explain its underlying forcing mechanism, and an even larger number of proxy reconstructions have been offered up to explain its temporal variability. These reconstructions have largely relied on tree rings, and have differed in their details. As expected, they capture different basic frequencies, emphasize different centres of action, and likely capture different aspects of the PDO while also expressing different local signals. Nevertheless, these various reconstructions largely agree about the fundamental nature of the PDO during the 20th century. However most of the published reconstructions of the PDO diverge in their characterization of its variability during the 19th century. In this presentation we show that these disagreements are not due to infidelities in the proxies or biases imposed by the calibration process, but are likely due to fluctuations in the strength of the PDO as a fundamental mode of variability. Both proxy and model results suggest that the bidecadal component of the PDO was likely weaker during the 19th century, and likely contributed to the disagreement between the various proxy reconstructions. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral DATING RESIN SCARS IN PINUS PINASTER 1

1

Mar Génova* , Leocadia Caminero , Javier Dochao

1

1

Universidad Politecnica de Madrid

In Spain, resin tapping constituted an important rural activity from the 1840s until the 1970s, when low prices made its exploitation economically unviable. During this period, resin from Pinus pinaster (maritime pine), became one of the most important non-timber products; now it is hard to find a long-lived forest of P. pinaster that has not been subjected to tapping for resin. Dating hidden scars inside the trunk caused by fire or geomorphological events, even in subfossil wood, is a common practice in Dendrochronology, but no studies reliably date resin scars by means of cross-dating. We conducted a dendrochronological study in a natural forest of maritime pine located in central Spain that had previously been subjected to resin tapping. There was a big fire in the region in the summer of 2008 and all the trees died. We analyzed cross sections of some tapped trees in order to date resin scars. We dated 46 scars, reconstructing the history of forest management which indicates an intensive resin extraction in the 1920-1950 period. We have broadened the study of the different types of events dated by means of scar analysis, and have explored for the first time the potential of dendrochronological scar analysis for reconstructing forest management history. *Indicates presenting author.

47

WorldDendro2014 Accepted Abstracts Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Poster SUBFOSSIL MACROREMAINS IN THE IBERIAN CENTRAL RANGE: PRELIMINARY RESULTS FROM NEW SITES 1

1

1

Mar Genova* , Fernando Gomez-Manzaneque , Felipe Martinez-Garcia , Jose Postigo-Mijarra

1

1

Universidad Politecnica de Madrid

Compared with the northern latitudes of Europe, the Iberian Peninsula is not a territory suitable for the preservation of tree macroremains. Consequently, only a few sites with subfossil macroremains have been studied, the Iberian Central Range being the most notable of these, due to the large number of remains analyzed. The Gredos mountain range, in the west, has been investigated for some time, and more recently we have been studying the Ayllon mountain range, in the east. In Gredos, radiocarbon dating and tree ring analysis within floating chronologies of subfossil pines have demonstrated its dendroecological potential. Two new sites are currently being analyzed in Ayllón. Dozens of new samples have been examined, and the chronologies time span has extended to 10,000 calibrated years BP. In addition, more paleoecological data have become available to explain the dynamics of the holocene pine forest in Central Spain. In one of the sites (Valdojos, municipal district of Campisábalos, Guadalajara province), 15 wood samples have been dated representing the oldest Holocene plant macroremains in the Iberian Central range. The analyzed remains have been ascribed to the genus Pinus and some have been determined as Pinus gr.sylvestris / nigra. The bigger logs have been analyzed using dendrochronological methods, and many of them have been found to have more than 200 rings. For the first time in Spain, some of the floating chronologies have been crossdated successfully. These include those with a known radiocarbon age, as well as others that have not been dated by radiocarbon. Theme: O11. Tree rings and radiocarbon Presentation Type: Poster RECENT ADVANCES ON DENDROGEOMORPHOLOGICAL RESEARCH APPLIED TO FLOOD HAZARD ANALYSIS IN SPAIN 1

2

1

1

Andres Diez-Herrero , Jose M. Bodoque , Juan A. Ballesteros-Cánovas , Virginia Ruiz-Villanueva , Mar 3 4 1 5 6 3 Génova* , Markus Stoffel , Carolina Guardiola-Albert , Miguel A. Eguibar , Pablo Mayer , Juan M. Rubiales 1

Instituto Geologico y Minero de Espana Universidad de Castilla-La Mancha 3 Universidad Politecnica de Madrid 4 Universitat Bern 5 Universidad Politecnica de Valencia 6 Universidad de Las Palmas de Gran Canaria 2

Over the last forty years, applying dendrogeomorphology to palaeoflood analysis has improved estimates of the frequency and magnitude of past floods worldwide. This communication reviews the main results obtained by applying dendrogeomorphology to flood hazard research in several case studies in Spain. These dendrogeomorphological recent advances focused on the following topics: (1) anatomical analysis to understand the physiological response of trees to flood damage and improve sampling efficiency; (2) compiling robust flood chronologies in ungauged mountain streams, (3) determining flow depth and estimating flood discharge using two-dimensional hydraulic modelling, and comparing them with other palaeostage indicators; (4) calibrating hydraulic model parameters (i.e. Manning roughness); and (5) implementing stochastic-based, cost-benefit analysis to select optimal mitigation measures. Further developments will include new methods for better identification of the causes of specific types of flood damage to trees (e.g. tilted trees) or stable isotope analysis of tree rings to identify the climatic conditions associated with periods of increasing flood magnitude or frequency. Innovative results have been obtained from the application of theses methodologies in different study sites in Spain, including ungauged basins in the Gredos Mountain Range and the Segovia province (Central Spain), and the Taburiente National Park (Canary Islands). The research projects DendroAvenidas (2008-2010) and MAS Dendro-Avenidas (2011-2014), both funded by the Spanish Ministery of *Indicates presenting author.

48

WorldDendro2014 Accepted Abstracts Science and Innovation (nowdays Ministery of Economy and Competivity), and the project IDEA-GesPPNN (2011-2013, Spanish Bureau of National Parks; Ministery of Agriculture, Food and Environment) are exploring these novel research lines. Theme: O07. Dendrogeomorphology Presentation Type: Poster DENDROGEOMORPHOLOGICAL RECORD IN LAS ANGUSTIAS STREAM ('CALDERA DE TABURIENTE' NATIONAL PARK, LA PALMA, CANARY ISLANDS, SPAIN) 1

2

2

3

1

Mar Génova* , Andres Diez-Herrero , Juan A. Ballesteros-Cánovas , Pablo Mayer , Juan M. Rubiales , Miguel A. 4 Saz 1

Universidad Politecnica de Madrid Instituto Geologico y Minero de Espana 3 Universidad de Las Palmas 4 Universidad de Zaragoza 2

Las Angustias is an ungauged stream located in the 'Caldera de Taburiente' National Park (La Palma, Canary Islands, Spain), where frequent and intense flash-flood events have taken place in the past causing fatalities and important economic damages (over 700,000 euros in the last two years). The aim of this research is to provide dendrogeomorphological data for the flood hazard analysis in one of the most visited areas of this protected park (more than 60,000 hikers per year). Since both local precipitation and flow data have important shortcomings regarding the lack of information, we have explored the use of disturbed trees of Pinus canariensis species to track past flash-flood events. All pine trees showing external evidence of flash flood (i.e., scars or exposed roots) were sampled by using increment borer. Additionally, in the dead trees with injuries we also obtained wedges of the overgrowing callus and complete sections with a chainsaw. Moreover, 16 undisturbed trees were sampled in order to obtain a reference chronology. Results indicate that over the last 50 years, nine flash-flood events have taken place. Especially relevant were the events occurring in 1962, 1979 and 1997, which presented a large number of replication. Dated events have been matched with available meteorological and documentary data to develop a multidisciplinary record representing the frequency of flood events. These and other data collected in our field work will improve flood hazard and risk analyses when using hydraulic models, and will be useful for National Park managers for land-use and visitors planning. Theme: O07. Dendrogeomorphology Presentation Type: Oral RECONSTRUCTIONS OF COLUMBIA RIVER (NORTHWESTERN USA) FLOW USING BOTH WINTER AND SUMMER PRECIPITATION-SENSITIVE TREES AND IMPLICATIONS FOR 21ST CENTURY WATER AVAILABILITY 1

1

Stephen Gray* , Jeremy Littell , Gregory Pederson

2

1

US Geological Survey-Alaska Climate Science Center, Anchorage, Alaska USA US Geological Survey-NRM Science Center, Bozeman, Montana USA

2

We combined information from both winter-snowpack sensitive and summer-drought sensitive tree-ring chronologies to generate reconstructions of annual streamflow for the Columbia River at The Dalles, Oregon U.S.A. These reconstructions extend back to the 16th century and have calibration R^2 of between 0.45 and 0.60. The full proxy record shows single to multi -year low flow events comparable to those in the instrumental record, but sustained low flows comparable to those observed in the 1920s and 1930s are rare. By capitalizing on our dual tree-ring proxy approach, we also see that low flows in the 1920s and 1930s resulted from relatively unusual pairings of low snowpack followed by summer dryness. The early 1600s and 1840s feature sustained low flows of similar intensity, but both events appear to be driven by a lack of summer precipitation rather than low snowpack. Likewise, our dual proxy approach shows that snowpack contributions to streamflow appear to have been greater in the past than in recent decades, and that these relative contributions also vary on decadal to multidecadal time scales. In turn, these results suggest that the full


49

WorldDendro2014 Accepted Abstracts range of potential climate-change impacts on regional hydrology may be significantly greater than would be indicated by observations alone. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral UNVEILING THE AVALANCHE ACTIVITY IN THE UPPER GOMS VALLEY (SWITZERLAND) OVER THE PAST 400 YEARS USING TREE-RING RECORDS AND HISTORICAL ARCHIVES 1

1, 2

Sebastien Guillet* , Markus Stoffel , Christophe Corona

3

1

Institute of Geological Sciences, University of Bern, Bern, Switzerland Environmental Sciences, University of Geneva, Geneva, Switzerland 3 Maison des Sciences de l'Homme, Geolab UMR 6042, Clermont-Ferrand, France 2

Snow avalanches are a major natural hazard in the Swiss Alps. Every year, they affect transport infrastructure (such as roads and railways). In the worst-case scenario high-magnitude avalanches may also endanger settlements and threaten human life. With the development of winter tourism industry over the past decades, mountains areas of Switzerland are every winter more densely frequented. Therefore to identify zones threatened by snow avalanches and reduce the exposure of people and properties, it has become crucial to build a database listing past avalanche events and providing accurate information regarding their magnitude, spatial extent and return period. In this study, we reconstruct the spatio-temporal patterns of avalanche activity in the Upper Goms Valley over the past 400 years. This high resolution chronology is, to date, one of the longest records ever elaborated for the Swiss Alps. 350 disturbed trees (Larix Decidua Mill., Picea Abies (L.) Karst) presenting growth disturbances related to avalanche activity have been sampled and analyzed. To complement dendrogeomorphic records and produce a chronology of past avalanche events as complete as possible we also investigated historical archives from the Goms valley. Theme: O07. Dendrogeomorphology Presentation Type: Oral THE BERKELEY EARTH SURFACE DATASET: A VALUABLE AND ALTERNATIVE TOOL TO RECONSTRUCT PAST TEMPERATURES 1

2

Sebastien Guillet* , Christophe Corona , Markus Stoffel

1,3

1

Institute of Geological Sciences, University of Bern, Bern, Switzerland Maison des Sciences de l'Homme, Geolab UMR 6042, Clermont-Ferrand, France 3 Environmental Sciences, University of Geneva, Geneva, Switzerland 2

A new monthly gridded temperature dataset has recently been released by the Berkeley Earth System project ◦ ◦ (BEST). This high resolution dataset (1 x1 ) is based on temperature records provided by more than 38000 weather stations distributed around the world and covering the period 1750-2012. So far no attempt has been made to use this dataset to reconstruct past temperatures. In order to evaluate the suitability of the BEST dataset for dendroclimatic reconstructions, we developed 35 summer temperature reconstructions based on a network of 110 TRW and MXD chronologies from North America, Europe, Siberia and central Asia. For each reconstruction, tree-ring data were calibrated against the gridded temperature data from BEST and the Climate Research Unit (CRU). Preliminary findings reveal that the BEST dataset can be used to calibrate with reliability tree-ring records back to 1880, which is a substantial improvement, considering that the CRU datasets (TS 3.10, 3.20) only extend back to 1901. Results also demonstrate that the use of the BEST dataset can significantly improve the robustness of reconstructions (R2, RE, CE) for several areas. The superiority of the BEST gridded data over the CRU dataset is however not systematic. Our study suggests that the two datasets are very complementary. We therefore strongly encourage dendroclimatologists to use the CRU gridded temperature data along with the BEST dataset which appears to be an excellent tool to calibrate tree-ring indices. Theme: O03. Methodological challenges in dendrochronology *Indicates presenting author.

50

WorldDendro2014 Accepted Abstracts Presentation Type: Poster SOURCE OF THE GREAT AD 1257 MYSTERY ERUPTION UNVEILED: SAMALAS VOLCANO, RINJANI VOLCANIC COMPLEX, INDONESIA 1

2

2

3

2

Sebastien Guillet* , Franck Lavigne , Jean-Philippe Degeai , Jean-Christophe Komorowski , Vincent Robert , 4 5 3 1,6 Pierre Lahitte , Clive Oppenheimer , Nicole Mietrich , Markus Stoffel 1

Institute of Geological Sciences, University of Bern, Bern, Switzerland Laboratoire de Geographie Physique, cnrs umr 8591, Meudon, France 3 Institut de Physique du Globe de Paris (IPGP), cnrs umr 7654, Paris, France 4 Departement des Sciences de la Terre (IDES), Universite Paris-Sud, Orsay, France 5 Department of Geography, University of Cambridge, Cambrige, United-Kingdom 6 Environmental Sciences, University of Geneva, Geneva, Switzerland 2

Polar ice core records attest to a colossal volcanic eruption that took place ca. AD 1258, most probably in the tropics. Estimates based on sulfate deposition in these records suggest that it yielded the largest volcanic sulfur release to the stratosphere of the past 7000 yr. Tree rings, mediaeval chronicles and computational models corroborate the expected worldwide atmospheric and climatic effects of this eruption. However, until now there has been no convincing candidate for the mid-13th century 'mystery eruption'. Drawing on compelling evidence from stratigraphic and geomorphic data, physical volcanology, radiocarbon dating, tephra geochemistry, and chronicles, we argue the source of this long-sought eruption is Samalas volcano adjacent to Mount Rinjani on Lombok Island, Indonesia. At least 40 km3 (dense-rock equivalent) of tephra were deposited and the eruption column reached an altitude of up to 43 km. Three principal pumice fallout deposits mantle the region and thick pyroclastic flow deposits are found at the coast, 25 km from source. With an estimated magnitude of 7, this event ranks amongst the largest Holocene explosive eruptions. Radiocarbon dates on charcoal are consistent with a mid-13th century eruption. In addition, glass geochemistry of the associated pumice deposits matches that of shards found in both Arctic and Antarctic ice cores, providing compelling evidence to link the prominent AD 1258/59 ice core sulfate spike to Samalas. We further constrain the timing of the 'mystery eruption' based on tephra dispersal, historical records and tree rings, suggesting it occurred between May and October AD 1257. Theme: Z01. Other Presentation Type: Poster USING PHYISCAL CHEMISTRY AND TREE RINGS TO CALCULATE THE LIKELIHOOD OF FIRE 1

2

1

1

2

Richard Guyette* , Frank Thompson III , Jodi Whittier , Michael Stambaugh , Daniel Dey , Rose-Marie Muzika

1

1

University of Missouri, Columbia, USA Northern Reseach Station US Forest Sevice, Columbia, USA

2

Climate has a primary influence on the occurrence and rate of combustion in ecosystems. Processes between the interactions of climate and fire are significant in evaluating changing ecosystems in the past, present and future. Tree-ring data has the temporal and spatial breath to calibrate the physical chemistry of fire-climate relationships. Here we present an empirically calibrated process model called the Physical Chemistry Fire Frequency Model (PC2FM). The process structure of the PC2FM is based on classical physical chemistry using the Arrhenius equation and concentration Rate Laws. The PC2FM processes are calibrated with 175 climatically diverse tree-ring dated fire scars records. We demonstrate the use of this hybrid empirical process model for estimating past and future fire frequency and probability. Mapped outputs for North America and Australia are shown and discussed. For future ecosystems the likelihood of a fire occurring is extracted from the rate of change defined by the fire-climate PC2FM regression. This represents a rate of change in fire due to climate forcing only. Thus, all estimates are “independent” of the many other important factors in fire regime. Means of precipitation and temperature from Global Climate Model (GCM) data are used in a physical chemistry framework to estimate future climate-forced fire probabilities. Expected change in fire frequency and probabilities are predicted by differencing PC2FM outputs using current and future climate data. The spatial output estimates for climate forced fire probabilities are determined by the scale of the climate data. *Indicates presenting author.

51

WorldDendro2014 Accepted Abstracts Theme: General Session Presentation Type: Oral ACOUSTIC EXPRESSION OF TREE RING DATA Richard Guyette*

1

1

University of Missouri, Columbia, USA

Auditory perception can be used to exploit and understand tree-ring series in ways that visual representations of tree-ring series cannot. Dendrochronology is uniquely equipped with methods and abundant time sensitive data for translating science with acoustics. The neurology of human brain offers distinct differences in perceiving scientific data with hearing when compared to graphic illustration. Perceiving time series of tree growth with sound is a real time expression with powerful new pathways for understanding tree rings data in science and society. Acoustic illustration is an expression of data and is not music. The objectives of this presentation are to: 1) demonstrate the basic concepts, methods, and probable requirements used for acoustic illustrations in dendrochronology, 2) show that auditory illustrations are legitimate methods for expressing tree-ring data and, 3) argue that the auditory illustration of tree-ring sequences has important implications for bringing dendrochronology to society, 4) and suggest data for acoustic figure captions such as: Title: River Oaks III; Temporal Axis Dimensions: time scale: 1092 years in 57 seconds, real time ratio: 19 yrs s-1; Acoustic Axis Dimensions: increased growth (mm) = increased pitch (Hz) and duration (s); Species (Quercus macrocarpa); Location: Missouri floodplains; Time series type: standardized ring-width index; Data: Stambaugh et al. 2011. The advent of digital sound technologies and online publishing now allow for enhanced auditory communication of dendrochronology. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral

H DENDROCHRONOLOGY IN SOUTHEAST QUEENSLAND: THE DIFFICULTIES ENCOUNTERED WHEN WORKING IN AND WITH THE TREES OF SUBTROPICAL AUSTRALIA 1

Heather Haines* 1

Australian Rivers Institute, Griffith University, Brisbane, Australia

Undertaking dendrochronological studies in subtropical and topical Australia has long been considered a difficult and relatively fruitless exercise (Ogden, 1978). Trees in these regions were deemed to produce poor annual ring growth and, where rings were present, difficulties were encountered in crossdating within and between trees by the presence of wedging, missing, and false rings. However, more recent applications in tropical environments have found that it is possible to develop chronological based studies with some of the species available in these regions. New techniques and methodological improvements have resulted in successful crossdating achievements. Very few studies however have included sites in subtropical regions with minimal work undertaken in Southeast Queensland. Research to develop chronologies to fill this gap has recently begun with collections from Toona ciliata, Callitris columellaris, Agathis robusta, Araucaria cunninghamii, and Araucaria bidwilli trees. The selected species have shown annual ring patterns either in Southeast Queensland or elsewhere in Australia with some known to crossdate better than others. This presentation focuses on reviewing some of the difficulties encountered when sampling in these dense subtropical rainforest environments and the issues arising from crossdating using the selected tree species. Ogden, 1978. On the dendrochronological potential of Australian trees. Australian Journal of Ecology, 3, 339356. Theme: O03. Methodological challenges in dendrochronology


52

WorldDendro2014 Accepted Abstracts Presentation Type: Oral SHRUB ECOLOGY - STATE OF THE ART AND FUTURE CHALLENGES 1

2

3

4

1

1

Martin Hallinger* , Eryuan Liang , Isla Myers-Smith , Ken Tape , Allan Buras , Martin Wilmking , Shrub Hub Data Synthesis Group, Shrub Hub Research Network 1

Institute of Botany and Landscape Ecology, University of Greifswald, Germany Institute of Tibetan Plateau Research,Chinese Academy of Sciences, Beijing,China 3 School of GeoSciences, University of Edinburgh, Edinburgh, UK 4 Institute of Arctic Biology, University of Alaska, Fairbanks, USA 2

The dendroecology of shrubs is still a rather young field of research with a few pioneering studies in the last century and even earlier on. Recently, while still in the shade of importance of the more researched trees, the number of shrub studies has grown vigorously, with exciting new studies, especially from Arctic, Sub-Arctic and alpine environments. While shrubs as a growth form share morphological characteristics with trees, they also differ in having regularly several stems and in their often decumbent growth form. Resource allocation, crown structure and differing responses to environmental conditions merit research efforts, as well as the potential of shrubs as climate archives in treeless areas. Our talk is a review of the current methodology, the main challenges and future opportunities for shrub-based research in dendrochronology. Therefore, we will present the preliminary results of a circumpolar shrub synthesis effort, including data from 34 sampling areas and 25 shrub species: so far no overall species- or size-related trend in climatic sensitivity could be found but a spatial trend of higher climatic sensitivity in the middle of the climatic gradient. Other case studies will highlight recent research progress of climate-growth and soil-growth interactions in the Himalaya, Scandinavia and Northern America. Theme: General Session Presentation Type: Oral LONG-TERM GROWTH AND CARBON SEQUESTRATION IN A SOUTHERN INDIAN TROPICAL DRY FOREST TREE BASED ON DENDROCHRONOLOGY 1

2

2

Suresh Hebbalalu* , Amar Sikder , Hemant Borgoankar , Sukumar Raman

1

1

Center for Ecological Sciences, Indian Institute of Science, Bangalore, India Indian Institute of Tropical meterology, Pashan, Pune, India

2

Some tropical trees such as teak (Tectona grandis, L.f.) have been shown to have potential for dendroclimatological reconstruction. We have been studying the long-term dynamics of a seasonally dry tropical forest in southern India using permanent plots; the observational data on growth in these plots are now complemented by examining growth and rate of carbon assimilation using annual growth rings of teak. Using 84 cores from 40 trees of different size and age (oldest tree dating from year 1601 and the youngest to 1958) we employed standard dendrochronological techniques to quantify growth. Mean growth of all trees across all years was 1.36±0.48 mm (N= 311 years) while growth of individual trees varied from 5.14 mm to 0.72 mm. Mean carbon sequestration varied from 57.8 kg to 16.0 kg per tree during 1730-2010. An increasing trend in growth and C sequestration was observed since 1900, a trend that was significant on a centennial scale. We found no evidence for possible “juvenile effect” or endogenous factors to explain the observed trends; thus environmental factors such as atmospheric CO2 enrichment may be responsible for the enhanced growth. Theme: O01. Tropical dendrochronology Presentation Type: Oral APPLYING CONFOCAL LASER SCANNING MICROSCOPY TO INCREMENT CORES FOR HISTOMETRIC ANALYSES 1

1

Ingo Heinrich* , Wei Liang 1

GFZ Potsdam, Potsdam, Germany


53

WorldDendro2014 Accepted Abstracts Recently, series of wood cell structures have proven to contain valuable ecological signals which m be used for long reconstructions. However, chronologies with an adequate sample depth and covering several centuries have not been achieved yet because the standard methods of quantitative wood anatomical research are quite demanding. Usually, many thin sections need to be prepared laboriously for further light microscopy analysis. Light microscopy images are always distorted towards the edges and thus merging images is difficult and the problem of measurement inaccuracies occurs. We have developed a novel procedure utilizing confocal laser scanning microscopy (CLSM) which has several benefits. The most important advantage is its ability to acquire high-quality images directly from the surface of increment cores, thereby no longer relying on microsectioning. CLSM systems use a laser scanning device relying on line scans. The results are distortion-free images which can easily be merged without the problem of different levels of distortion in the individual images. The output files are simple monochrome images most suitable for further digital imagery focusing only on the two parameters cell lumen and wall. Consequently, image analysis software is used to measure wood anatomical parameters such as cell size, wall thickness and lumen area. In the presentation, the novel procedure will be illustrated, first promising results shown and its potential applications discussed. We will also focus on data treatment concerning age/youth trend and climate sensitivity of samples from well within the latitudinal and altitudinal limits of the species' distribution in the temperate regions. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral ANNUAL GROWTH INCREMENT AND STABLE ISOTOPE VARIABILITY IN WOODY PLANTS WITH C3- AND C4PHOTOSYNTHETIC PATHWAYS 1

1

2

3

4

Tishanna Ben , Patrick Hart , Brian Schubert , Edward Cook , Gerd Helle* , Kainana Francisco

1

1

University of Hawaii at Hilo, Hilo, USA University of Louisiana at Lafayette, Lafayette, USA 3 University of Columbia, New York, USA 4 Helmholtz-Centre Potsdam, Potsdam, Germany 2

Tree ring patterns provide one of the best records of historical climate variability. We evaluated growth increment periodicity and the stable isotope ratios of carbon and oxygen in two woody plant species using the C3- and C4-photosynthetic pathways. The investigated species, Mamane (Sophora chrysophylla, C3) and Akoko (Euphorbia olowaluana, C4), are small endemic Hawaiian trees sampled from a rather dry, high elevation habitat on the ridge between Mauna Loa and Mauna Kea on the island of Hawaii, USA. We found a relatively strong correlation in ring patterns between the Akoko and the Mamane individuals as well as with ring patterns from a nearby population of introduced pine trees. This is evidence that the C4-plant Akoko may form annual growth rings. In addition to being the first demonstration of annual growth rings in a C4 plant, our findings have important implications for future climate change research in Hawaii. Unlike plants with a C3photosynthetic pathway, C4 plants do not show strong bias against 13C during the photosynthetic fixation of CO2. Thus, Akoko may provide a record of past atmospheric CO2 concentration that can be compared with, and possibly supplement, the well-known Keeling curve produced by the nearby Mauna Loa Atmospheric Observatory. Furthermore, time series of tree ring data from both species provide long-term information on the response of C3 and C4-plants to increasing atmospheric CO2 concentrations and climate change. We will present recent trends in growth increment, d13C (water-use efficiency) and d18O of the two species and discuss differences and similarities in their response to environmental change. Theme: O01. Tropical dendrochronology Presentation Type: Oral PLUVIALS, DROUGHTS, THE MONGOL EMPIRE AND MODERN MONGOLIA 1

2

3

4

2

Amy Hessl* , Neil Pederson , Baatarbileg Nachin , Kevin Anchukaitis , Caroline Leland , Kristen DeGraauw

1

1

West Virginia University, Morgantown, USA Columbia University, Palisades, USA

2


54


National University of Mongolia, Ulaanbaatar, Mongolia Woods Hole Oceanographic Institution, Woods Hole, USA

4

Climate variability has large impacts on society, particularly societies that are directly tied to local net primary productivity through agriculture or pastoralism. Understanding the connections between climate, energy, and society during historical and modern climatic transitions requires annual resolution records with high fidelity climate signals. Semi-arid regions like Mongolia are especially sensitive to small changes in the climate state and are also projected to experience the early consequences of anthropogenic climate change. We present a 2600 year, annually resolved record of water availability from tree growth in central Mongolia that places historic and modern social change in the context of millennia of climatic variability. Our record covers the climate during several nomadic empires centered in Mongolia, including the conquests of Chinggis Khaan's (Ghengis Khan's) 13th century Mongol Empire. This long record also allows us to contextualize a 21st century drought associated with the mass migration of more than 200,000 people to the capital city of Ulaanbaatar. Placing these events in climatic context is the first step towards understanding how societies may make energetic alliances with climate or suffer from climatic dissonance. Theme: S02. Civilisations, climate and tree rings Presentation Type: Oral STABLE ISOTOPE PALEOCLIMATOLOGY OF THE EARLY EOCENE USING MUMMIFIED WOOD FROM THE CANADIAN ARCTIC 1

1

2

1

1

3

1

Benjamin Hook* , Jochen Halfar , Ze'ev Gedalof , Jorg Bollmann , Azizur Rahman , Julito Reyes , Dan Schulze 1

University of Toronto, Toronto, Canada University of Guelph, Guelph, Canada 3 Natural Resources Canada, Calgary, Canada 2

The Early Eocene (ca. 53 Ma) was characterized by intense global warmth due to high levels of atmospheric carbon (>900 ppm pCO2). In the Arctic, temperatures were 10 - 17°C higher than modern, and permanent polar ice did not exist. In this unique biome, tree growth was prodigious despite continuous daylight/night for part of the year. The discovery of well-preserved Pinaceae mummified wood in Early Eocene kimberlite mines (Lac de Gras, NWT, Canada) permits a paleoclimatic study using tree-ring and stable isotope analyses. The wood is not petrified, but remains woody by their inclusion in an anaerobic kimberlite matrix. We have extracted primordial δ±-cellulose from the mummified wood and measured δ13C and δ18O, finding highly enriched values compared to modern levels in this location (δ13C=-20.9±0.33%, n=14; δ18O=24.7% ±0.77%, n=14). These results suggest a warm climate with a mean annual temperature (MAT) of 9.25±3.6°C. Presentday MAT in nearby Yellowknife, NWT is -4.6°C, therefore Early Eocene MAT was 14°C warmer on average than modern Arctic temperatures. Spectral analyses of detrended tree-ring widths detected significant growth variability on timescales similar to the modern Pacific Decadal Oscillation (Eocene PDO: 22.5 -“ 60 years; Modern PDO: 20 - 50 years) and El Nino - Southern Oscillation (Eocene ENSO: 2 -“ 3 years; Modern ENSO: 2 7 years). These results taken together suggest that the Early Eocene was significantly warmer than now, although climate oscillations were similar to modern PDO and ENSO. This is the earliest observation of PDO and ENSO variability in an annual resolution paleoclimate archive. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral MODIFIED BRENDEL δ±-CELLULOSE EXTRACTION METHOD FOR USE WITH KIMBERLITE-HOSTED MUMMIFIED WOOD 1

1

2

1

1

3

1

Benjamin Hook* , Jochen Halfar , Ze'ev Gedalof , Jorg Bollmann , Azizur Rahman , Julito Reyes , Dan Schulze 1

University of Toronto, Toronto, Canada University of Guelph, Guelph, Canada 3 Natural Resources Canada, Calgary, Canada 2


55

WorldDendro2014 Accepted Abstracts Mummified wood is an important paleoclimatic resource because it is not petrified, but composed of primordially formed wood material. The discovery of mummified wood in Canadian Arctic kimberlites prompted a paleoclimatic study of the Early Eocene (ca. 53 Ma). During kimberlite eruption, contemporary wood was encased and preserved. Vitrinite reflectance measurements of the wood (%Ro = 0.23, n = 40) reveal that kimberlite emplacement temperatures were low ( 1000-year long tree-ring width (TRW) chronologies from Fennoscandia used to infer past climate variability rely on subfossil wood from mountain lakes. Often several generations of trees can be found in one lake, spanning over several thousands of years. However, during these timescales, the local tree-line has likely varied with climate, and possibly there is an added constraint from the near-shore environment, which may have influenced the sensitivity of the trees to summer temperatures. To assess this, we used new chronologies from deadwood on sites assumed to represent the local tree-line in two periods; the 11th century and 14-15th century CE, situated ca. 100 meters above the present tree line. This dataelieved to contain the strobgest temperature information, is compared to contemporary subfossil wood TRW chronologies from lakes situated approximately 200 meters below. This provides us with a unique mean to study possible divergences between subfossil and deadwood on different timescales and to evaluate the climate information gained from lake subfossil wood. Theme: Z01. Other Presentation Type: Poster CAN BLUE LIGHT INTENSITY BE USED AS A CLIMATE PROXY IN PATAGONIAN TREE-RINGS? A CASE STUDY ON NOTHOFAGUS BETULOIDES AND PILGERODENDRON UVIFERUM FROM SOUTHERN PATAGONIA 1

1

2

1

Mauricio Fuentes , Hans Linderholm* , Juan Aravena , Jesper Bjorklund , Kristina Seftigen

1

1

Dep. of Earth Sciences University of Gothenburg, Gothenburg, Sweden Center for the Quaternary Studies CEQUA Foundatio , Punta Arenas, Chile

2

Compared to the Northern Hemisphere, there is a general lack of high-resolution paleoclimate records from the Southern Hemisphere (SH). Patagonia, situated in southernmost South America, is a key region in the SH due to its geographical location, influence of the large scale circulation in the oceans and the atmosphere and proximity to Antarctica. Observations suggest that changes in the atmospheric circulation has affected this region e.g. through changes in precipitation patterns. While several paleoclimate studies using tree-ring width records from Patagonia have emerged in recent years, hardly no studies have assessed the possibility to *Indicates presenting author.

75

WorldDendro2014 Accepted Abstracts increase the knowledge of past climate variability using other tree-ring proxies, such as isotopes or maximum latewood density. Here we present the first results of a study where optical flatbed scanner produced minimum blue intensity (BI) measurements, which have been shown to be an excellent proxy for maximum latewood density in the Northern Hemisphere, were extracted from two species, Nothofagus betuloides and Pilgerodendron uviferum, in southernmost Patagonia. Sampling of the trees were made along a west-east gradient of decreasing influence from the westerlies, from the western part of the Strait of Magellan to Tierra del Fuego, with the aim to evaluate the observed climate changes along this gradient in a long-term context. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Poster SIX TEMPERATURE PROXIES OF SCOTS PINE FROM THE INTERIOR OF NORTHERN FENNOSCANDIA COMBINED IN THREE FREQUENCY RANGES 1

2

Markus Lindholm* , Maxim Ogurtsov , Risto Jalkanen

1

1

Metla, Rovaniemi, Finland A.F. Ioffe Physico-Technical Institute, St. Petersburg, Russia

2

Six chronologies based on the growth of Scots pine - three ring width, two density and one height growth from the inland of northern Fennoscandia were built to separately enhance low, medium and higher frequencies in growth variability in 1000-2002. Several periodicities of growth were found in common in these data. Five of the low-frequency series have a significant oscillatory mode at 200-250 years of cycle length. Most series also have strong multidecadal scale variability, significant peaks at 33, 67 or 83-125 years. Reconstruction models for mean July and June-August as well as three longer period temperatures were built and compared using stringent verification statistics as tests. We describe main differences in model performance (R2=0.53-0.62) between individual proxies as well as their various averages depending on provenance and proxy type, length of target period and frequency range. A separate medium-frequency JuneAugust temperature reconstruction is presented, which is closely similar in amplitude and duration to the last two cycles of the Atlantic Multidecadal Oscillation (AMO). The good synchrony between these two series is only hampered by a 10 years difference in timing. Recognizing a strong medium-frequency component in Fennoscandian climate proxies helps to explain part of the uncertainties in the 20th century trends, e.g. a multidecadal periodicity in the early part taking place along an overall centennial warming trend and thus integrating natural and external components. Theme: General Session Presentation Type: Oral DROUGHT AND FOREST MORTALITY IN INNER ASIA 1

2

3

2

1

Hongyan Liu* , Oleg Anenkhonov , Andrey Korolyuk , Denis Sandanov , Chongyang Xu , Zhaohuan Qi

1

1

College of Urban and Environmental Sciences, Peking University, Beijing, China Inst. of General and Experimental Biology, SB, Russian Acad. of Sci., Russia 3 Central Siberian Botanical Garden, SB, Russian Acad. of Sci., Russia 2

At global scale, forest mortality has been mostly occurred in the forest-steppe ecotone (Allen et al., 2009). The effects of forest edge, patch size and tree species can not be ignored besides the effect of drought. In addition, how tree growth and forest mortality are related remains unclear because few stand-total sampling has been conducted. We hypothesize that forest mortality is closely related to tree growth decline at community level through stand-total sampling of tree-ring in southern Siberia of Russia and northern China. A systematical count of seeds, seeding, sapling, dead tree and living trees for each stand from forest edge to interior at forest patches with different sizes was also conducted. Our results show that forest mortality has been limited to the driest sites of the forest-steppe ecotone in all subregions except Northwest China. The forest types with high mortality cover all dominant tree species, e.g. Pinus sylvestris, Ulmus pumila, Larix sibirica, Larix gmelinii, Populus davidiana, and Betula platyphylla, in this region. At site level, however, no edge effect was found. Higher proportion of forest mortality and decline in tree growth was found on smaller patches under dryer *Indicates presenting author.

76

WorldDendro2014 Accepted Abstracts climate, implying that tree growth decline and forest mortality was strongly coupled in small forest patch with dry climate. Forest regeneration is also difficult at these sites, implying a worsening future of small forest patches given climate drying in this region continues. Theme: O08. Drought and mortality Presentation Type: Oral THE SUPERIORITY OF NUMERICAL MIX METHOD IN TREE-RING STABLE-CARBON ISOTOPE BASED MAY-JULY TEMPERATURE RECONSTRUCTION OVER NANWUTAI, CHINA FOR THE PAST CENTURY 1,2

1

Yu Liu* , Qiang Li , Yanchao Wang 1 Zhisheng An

1,2,3

1,3

4

5

1

, Huiming Song , Steve Leavitt , Hans Linderhlom , Ruiyuan Wang ,

1

Institute of Earth Environment, Chinese Academy of Sciences School of Human Settlements and Civil Engineering, Xi’an Jiaotong University 3 The University of the Chinese Academy of Sciences 4 Laboratory of Tree-Ring Research, University of Arizona 5 Regional Climate Group, Department of Earth Sciences, University of Gothenburg 2

By analyzing two groups of Chinese pine from the Nanwutai region of the Qinling Mountains, China, one group including three trees that were analyzed separately, the other comprising four other trees that were pooled prior to preparation and analysis, we found that correlations between the meteorological data and all individual and pooled discrimination (δ13C) series revealed significant negative responses to temperature for several specific months. The relationship of the numerical mix model δ13C (averaging of the three individual δ13C series) with temperature was stronger than that of the pooled series, suggesting numerical mixing of series can be more effective than raw wood sample pooling at least according to the trees in Nanwutai. Based on the numerical mix model, we reconstructed the mean May-July temperature (TM-J) over the past century for the Nanwutai region. The explained variance is 43.3% (42.1% after adjusting the degrees of freedom). Compared to a ring-width temperature reconstruction (May-July) from the same site, the stable-carbon isotope-based reconstruction offers two distinct advantages: 1) it captures a wider range of temperature variability; and 2) the reconstruction preserves more low-frequency climate information. The 20th century warming was well represented in the reconstruction. A spatial correlation analysis showed the representative of the reconstruction for climate variations over the entire Loess Plateau in north-central China. Periodicity analyses and significant correlations between the reconstruction and ENSO, as well as SSTs suggest that the temperature variability in the Nanwutai region may be linked to Pacific and Indian Ocean SST variations and solar activity. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Poster SIMULTANEOUS DETERMINATION OF CARBON, OXYGEN AND HYDROGEN ISOTOPES IN TREE-RING CELLULOSE 1

2

2

2

2

1

Neil Loader* , Markus Leuenberger , Adam Kimak , Malin Ziehmer , Peter Nyfeler , Street-Perrott Alayne 1

Swansea University, Swansea, UK University of Bern, Bern, Switzerland

2

The stable isotope analysis of tree-rings for palaeoclimate and plant physiological research is most often conducted on the cellulose component of the wood. As such, there is potential to study isotopic discrimination in carbon, oxygen and hydrogen stable isotopes in this the most common biopolymer. The chemical composition of cellulose however makes it challenging to analyse all three elements in a single sample. We present results from a new development in sample preparation that permits a triple-isotope approach. The new system is demonstrated to perform as well as single-element methods and offers exciting new potential for understanding fluxes of carbon dioxide and water in the natural environment. Theme: O03. Methodological challenges in dendrochronology *Indicates presenting author.

77

WorldDendro2014 Accepted Abstracts Presentation Type: Oral HIGH-RESOLUTION STABLE ISOTOPE ANALYSIS OF TREE-RINGS BY LASER-ABLATION ISOTOPE RATIO MASS SPECTROMETRY 1

1

2

Neil Loader* , Danny McCarroll , Sam Barker 1

Swansea University, Swansea, UK Sercon Ltd, Crewe, UK

2

Results are presented from a laser-ablation interface designed for the stable carbon and oxygen isotope analysis of tree rings. The technique is described with reference the potential of the method, results obtained and the need for new data-processing considerations. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Poster ISOTOPE DENDROCLIMATOLOGY IN RINGLESS TROPICAL TREES 1

1

2

Neil Loader* , Danny McCarroll , Dmitri Mauquoy , Rory Walsh

1

1

Swansea University, Swansea, UK Aberdeen University, Aberdeen, UK

2

Results are presented from a pilot study of stable and radiogenic isotopes in the long-lived tropical species Eusideroxylon zwagerii sampled from the ever-wet aseasonal rainforest of Sabah, Malaysian Borneo. As these trees do not produce reliable annual rings we adopt methods from the field of sedimentology to develop probabilistic age-growth relationships and a timescale within which to express stable isotopic variability. This technique provides an alternative approach to high-resolution sampling for the analysis of environmental trends in ringless tropical trees. Theme: O11. Tree rings and radiocarbon Presentation Type: Oral

M USING DENDROECOLOGY, PERMANENT PLOTS, AND STAND GROWTH MODELS TO UNRAVEL EFFECTS OF SPRUCE BUDWORM OUTBREAKS UNDER CHANGING CLIMATE 1

David MacLean* 1

University of New Brunswick, Fredericton, Canada

Spruce budworm (Choristoneura fumiferana) outbreaks occur every 30-40 years in eastern North American balsam fir (Abies balsamea) and spruce (Picea sp.) forests and cause large uncertainty about forest development and productivity. Growth reduction caused by spruce budworm is proportional to cumulative defoliation, and typically exceeds 90% of pre-defoliation annual radial and volume growth. Dendroecological studies have long been used to date historical spruce budworm outbreaks, and I will describe our use of them and permanent plots to determine relationships between growth reduction and tree species, age, site characteristics, and surrounding forest conditions. Determining key relationships between reductions in tree growth and survival versus defoliation levels requires permanent sample plots where defoliation is annually measured at the tree level. Dendroecology is a powerful tool that helps provide one piece of the puzzle, but in addition to tree growth, understanding tree mortality rates (both without and with insects) and regeneration processes are needed to determine forest responses to both climate change and insect outbreaks. Eastern Canada in now undergoing a new spruce budworm outbreak, with over 2.4 million ha of moderate-severe


78

WorldDendro2014 Accepted Abstracts defoliation in 2012 in Quebec and populations rising in the adjacent province of New Brunswick. I will describe dendroecology data for spruce budworm from previous outbreaks in New Brunswick, a recent study of spatial variability and temporal patterns of defoliation spanning 1965-1992, and the use of process-based stand growth models to study climate change projections for forests in the region. Theme: O09. Insect outbreaks Presentation Type: Oral DENDROCHRONOLOGICAL RECORD OF SMALL SCALE EARTHQUAKES IN WOOD OF PICEA ABIES KARST. AND POSSIBILITY FOR RECONSTRUCTING PAST SEISMIC EVENTS 1

1

1

Ireneusz Malik* , Malgorzata Wistuba , Anna Abramowicz , Patrycja Michalowicz

1

1

University of Silesia in Katowice, Faculty of Earth Sciences, Sosnowiec, Poland

Examples of tree stand destruction under the impact of strong earthquakes are well known, they were described in e.g. Alaska in 1964 and Japan in 2008. Yet, little is known on dendrochronological records of weaker earthquakes with 3-5 magnitudes (M) which are common all over the Earth (c. 20 000 events per year). These earthquakes occur also in Poland where magnitudes usually do not exceed 5. During last decades two main earthquakes occurred in 1995 (2,91,000km2 burnt) tended to occur when drought conditions followed wet, cool conditions in the preceding year, i.e. when fuel loads and connectivity were significantly greater. Our results confirm that Callitris has significant dendroecological potential to not only accurately date past fire events but to also understand the intensity and frequency of climatic extremes that largely determine the incidence and extent of fire across much of semi-arid Australia. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral FINGERPRINTING THE 536AD CLIMATIC ANOMALY – TREE RING WIDTH, DELTA13C AND DELTA14C IN MULTIPROXY EVENT RECONSTRUCTION 1

1

2

3

Markku Oinonen* , Laura Arppe , Samuli Helama , Kari Mielikäinen , Mauri Timonen

2

1

Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland


88


Finnish Forest Research Institute, Rovaniemi, Finland Finnish Forest Research Institute, Vantaa, Finland

3

Firm historical and proxy evidence (Arjava 2005, Larsen et al 2008) suggest that the most severe short term cold episode across the Northern hemisphere in the last two millennia took place following the climate anomaly in 535-536AD. It has been suggested that a volcanic eruption around 535AD caused a dust veil in Europe in 536AD, yielding crop failures and spread of diseases (Baillie 1994). This work uses tree-ring archives of subfossil pinewood from northern Finnish Lapland and combines tree-ring width, delta13C and delta14C information to establish a multiproxy event reconstruction of the anomaly with annual resolution. The anomaly is clearly visible also in the delta13C data. Role of the dimming of the solar radiation and cooling of the temperature is addressed, together with possibilities of using annual delta14C information as an environmental proxy. Arjava A (2005) The Mystery Cloud of 536 CE in the Mediterranean Sources. Dumbarton Oaks Papers 59: 73-94. Baillie M G L (1994) Dendrochronology raises question about the nature of the AD 536 dustveil event. Holocene 4:212-217. Larsen L B et al (2008) New ice core evidence for a volcanic cause of the A.D. 536 dust veil, Geophys. Res. Lett., 35, L04708, doi:10.1029/2007GL032450. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral DIGITAL IMAGE RESOLUTION: HOW HIGH IS HIGH ENOUGH FOR DENDROCHRONOLOGICAL ANALYSIS? ANALYZING HINOKI CYPRESS TEE-RING WIDTHS USING DIGITAL PHOTOGRAPHY AND MICROFOCUS X-RAY COMPUTED TOMOGRAPHY. 1

Takayuki Okochi* 1

Nara National Research Institute for Cultural Properties, Nara, Japan

The most basic step in dendrochronology is measuring the widths of tree rings. In the past ten-odd years, with the marked advances and popularization of digital imaging technologies, the methods for measuring tree rings have also expanded beyond the conventional method of using tree-ring measuring machine. In particular, buildings, large sculptures, paintings, and other cultural materials are difficult to put in place to enable dendrochronological measurements to be taken with a tree-ring measuring machine. In such cases, it is effective to use digital photography to take these measurements. The non-destructive tree-ring measurement technology of microfocus x-ray computed tomography is also a type of digital imaging technology. In such cases of using images as an intermediary through which to digitize tree-ring width data, it is imperative, as the first step in the process, to photograph the object of study as clearly and sharply as possible. One particularly important factor in the digitization of tree-ring data is image resolution. The quality of image resolution dictates whether the tree-ring boundaries can be identified correctly, and has an impact on the occurrence of missed or double counts. Image resolution also affects the precision of each tree-ring width measurement. In this presentation, I will discuss a case study of hinoki cypress, which is a representative conifer species in Japan, from the perspective of digital imaging, to consider the appropriate image resolution settings for the digitizing and measuring tree-ring images. I also plan to propose some suitable standards for the digital measurement of tree-ring widths, especially of conifer species. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral THE 900-YEAR-OLD JUNIPERUS SERAVSCHANICA FROM ZARAFSHAN MOUNTAINS, WESTERN PAMIR-ALAY (TAJIKISTAN) – THE POTENTIAL FOR CLIMATIC RECONSTRUCTION OF CENTRAL ASIA 1

1

1

Magdalena Opala* , Tadeusz Niedzwiedz , Oimahmad Rahmonov 1

University of Silesia, Sosnowiec, Poland

The studies of climate variability over centuries requires long and reliable measurement series, which for most mountain areas also in the region of Central Asia, are few and rarely extend beyond the last century. In climate reconstructions of the remote mountain ranges proxy data are therefore of great importance. Area of the *Indicates presenting author.

89

WorldDendro2014 Accepted Abstracts western Pamir-Alay remains a significant gap in research on the reconstruction of last millennium climate. Only two dendrochronological sites from Tajikistan (J.turkestanica) have been reported earlier. The objectives of our study were to explore the dendrochronological potential of local shrub species and to identify the climatic factors controlling its radial growth. Field work was carried out in the Zarafshan Mountains, altitude between 2200-2800 m a.s.l. A set of samples from different species were collected and evaluated in terms of their potential for dendroclimatic studies. The best prospects for this appear to be Juniperus seravschanica Kom., which was clearly the oldest with some specimens reaching 900 years. Climatic data obtained from the nearest weather station showed strong correlation and was found useful for tree-ring climate analysis. Shrubs growing on the slopes, in addition to the climate signal, may also record geomorphological signals. The current study suggests applicability of J. seravschanica not only in the proxy climate investigations, but also the contemporary dynamics of the natural environment of this part of Central Asia, which is a very sensitive area, quickly responding to contemporary climate change. This work was financially supported by the Faculty of Earth Sciences University of Silesia. Theme: O10. Shrub dendroecology Presentation Type: Poster THE INFLUENCE OF AIR POLLUTANTS ON CHANGES IN THE TREE RINGS WIDTH - A CASE STUDY FROM SILESIA INDUSTRIAL REGION, POLAND 1,2

Magdalena Opala* , Barbara Sensula

2

1

University of Silesia, Sosnowiec, Poland Silesian University of Technology, Gliwice, Poland

2

The poster presents the studies concerning tree rings width as bioindicators of industrial air pollutants from the plants with different industries in the period of industrial development and the implementation of EU law. The aim of the research are: (1) the reconstruction of anthropogenic and climatic effects and (2) monitoring of the influence of human activities related to industrial development and the introduction of pro-environmental policy. The Silesia province, one of the most polluted areas in Poland, were chosen for the studies. Due to a lack of air pollution data, the historical perspectives on past environmental disasters can be provided by natural archives, such as tree rings. Samples of Scots pine were collected in close proximity to three industrial sites, considered as one of the most environmentally hazardous plants in Poland: Katowice Steelworks, Laziska Power Station and Kedzierzyn Nitrogen Plant. Analyses were performed taking into account the distance from the emitter, elevation, exposure in relation to the wind direction and the circulation type favorable to the concentration or dispersion of pollutants. The dendrochronological results, conducted in three separated transects, showed the abrupt and long term reductions observed in radial increments of sampled trees. Duration of growth reduction varies for each plant: circa 1960-1980 for Katowice, 1960-1990 for Laziska and 1970-1990 for Kedzierzyn. The distribution of pollution signals in particular sites indicate a distinct relationship between the amount of reductions, distance from local source of pollution and its type. This work was financially supported by the National Science Centre (Decision No.DEC-2011/03/D/ST10/05251). Theme: Z01. Other Presentation Type: Poster THE CONTINUITY OF CELL DIVISION AND THE RESUMPTION OF XYLEM DIFFERENTIATION OF NEW CAMBIAL DERIVATIVES AFTER THE CAMBIAL REACTIVATION INDUCED BY LOCALIZED STEM HEATING IN TEMPERATE ZONE TREES 1

2

Yuichiro Oribe* , Shahanara Begum , Ryo Funada

3

1

Forestry and Forest Products Research Institute, Takizawa-Iwate, Japan Bangladesh Agricultural University, Mymensingh, Bangladesh 3 Tokyo University of Agriculture and Technology, Fuchu, Japan 2

In trees growing in temperate zone such as Japan, the vascular cambium usually has annual periods of activity and winter dormancy. The periodicity of cambial growth, which comprises maintenance of the cambium itself *Indicates presenting author.

90

WorldDendro2014 Accepted Abstracts and production of cambial derivatives as well as formation of secondary xylem and phloem, is responsible for annual-ring formation. Re-initiation of annual-ring formation, therefore, can be divided into cambial reactivation and resumption of xylem differentiation of new cambial derivatives, which are formed by the reactivated cambium. The localized heating of the stems of trees has revealed that increasing air temperature triggers cambial reactivation in both conifers and broad-leaved trees. Therefore, increase or decrease of air temperature in early spring due to global climate change would affect the periodicity of annual-ring formation in trees, and then might alter their wood structure, namely annual-ring width and earlywood width. However, our experimental model system using locally heated stem has revealed that both the continuity of cell division and the resumption of xylem differentiation of new cambial derivatives require additional factors after the cambial reactivation. Here, we present results of our heating experiment and discuss the mechanism regulating the re-initiation of annual-ring formation by environmental and endogenous factors in trees growing in temperate zone. Theme: O02. Measuring and modelling wood formation Presentation Type: Oral THE DENDROCHRONOLOGY OF HIGH ARCTIC DWARF SCHRUB SALIX POLARIS - CHRONOLOGY DEVELOPMENT AND CLIMATE RESPONSE 1

Piotr Owczarek* , Magdalena Opala

2

1

University of Wroclaw, Wroclaw, Poland University of Silesia, Sosnowiec, Poland

2

Salix polaris (Wahlenb.) is common dwarf shrub growing in the south part of the Spitsbergen Island. The Spitsbergen has periglacial climate often referred as the â€œHigh Arctic climateâ€ with extremely weak diurnal and strong seasonal patterns. S polaris is deciduous and creeping plant usually less than 8 cm tall. The aims of this study were: (1) to construct a S. polaris growth chronology for a High Arctic site, (2) to examine a potential of this dwarf shrub in climatic research. 70 samples were collected from the flat marine terraces from SW Spitsbergen and the Bear Island during 2007, 2011 and 2012. In order to avoid discontinuous and missing rings serial sectioning and ring widths measurements along the two radii were applied for every shrub. The growth sequences were visually cross-dated and then statistically checked with COFECHA. The final chronology was composed of 16 polar willow ring width series, which span 63 years (1947-2010). Mean correlation between series is 0.50, mean ring width is 155 µm and mean sensitivity is 0.47. A ring-width chronology was developed after a straight line of any slope had been fit to the raw measurements. Then, to evaluate their dendroclimatological potential, correlations were calculated between the standard ring-width chronology and monthly climate data recorded in the Polish Polar Station in Hornsund. The polar willow ring width variability is positively correlated with precipitation (June and annual sums) and negatively correlated with minimum (June and October) and maximum (October) temperature of the year preceding the ring formation. Theme: O10. Shrub dendroecology Presentation Type: Poster THE IMPACT OF PAST INDUSTRIAL POLLUTION ON TREE-RING WIDTH IN THE WAÂBRZYCH REGION (SW POLAND) 1

2

2

1

Filip Duszyaski , Agnieszka Bukietynska , Mariusz Czekala , Piotr Owczarek* 1

University of Wroclaw, Wroclaw, Poland Institute of Quantitative Methods, Wroclaw School of Banking, Poland

2

Until the late 70s of the last century, coal power plants and coking plants were operating in Waâbrzych causing harmful air pollution. Although the production volume was decreasing considerably since then, the city was listed among the most ecologically threatened places in Poland in 1983. The main objective of the study was to assess the impact of the pollutants on the nearby trees. Samples of Norway Spruce (Picea abies L.) were collected from three research sites. While two of them were located on the slopes of mountain ridges *Indicates presenting author.

91

WorldDendro2014 Accepted Abstracts surrounding the most essential pollution sources, the third one was a reference site, situated about ten kilometres away. The results show that the highest production volume of coke, that is between the 1960s and the 1980s, was reflected in the considerable reduction of tree-rings. This negative correlation has been proved to be statistically significant. There are, however, some differences between the chronologies developed for the site located to the west of WaÅ‚brzych and the one in the north-east. Namely, the former shows a more conspicuous increase which begins in the 1980s along with the improvement of the air quality in the region. The delayed reaction of the trees growing in the north-east might have resulted from the south-west wind dominating in the area that carried polluted air masses directly to the site. The studied phenomenon is not observed in the reference chronology, though, which proves the local origin of the tree-ring reduction on the researched sites. The pollution impact was altered by meteorological conditions. Theme: Z01. Other Presentation Type: Poster POLLUTION OR GEOMORPHOLOGICAL SIGNALS IN TREE-RING SEQUENCES - PRELIMINARY RESEARCH RESULTS FROM THE KARKONOSZE MTS, POLAND 1

1

1

Piotr Owczarek* , Michal Godek , Marek Blas , Mieczyslaw Sobik

1

1

University of Wroclaw, Wroclaw, Poland

Since the 1970s spruce trees (Picea abies L.)in the Karkonosze Mts (SW Poland) have been affected by largescale dieback caused mainly by strong anthropogenic air pollution emission and deposition. In the upper part of the mountains (ca. 1200 m a.s.l.) fog becomes a crucial pathway of pollutant deposition, furthermore fog deposition is much more spatially variable than wet deposition carried by precipitation. These steep slopes are disturbed by large debris flow processes that are repeated every 10 - 15 years after extremely rainfall events. The aim of the study is compare growth-ring disturbances connected with pollution and mass movement impacts. Three sites were selected to detailed research located at the elevation 1000 - 1300 m a.s.l. in the highest part of the mountains. Samples were collected along transects 300 - 400 m long, located in the subalpine forest zone. The research indicate that all subalpine sites a gradual reduction of tree rings width is visible at the end of the 1970s and the beginning of the 1980s but in every population are individuals that reacted either modestly, strongly or very strongly to events. Abrupt growth reductions were found in wounded trees which are affected by debris flow events (e.g. 1966, 1982, 1994, 2007). These signals are overlapped on a modest growth decline in the 1970s caused by air pollution. The geomorphological signals in the tree-ring chronologies, in to the reaction on pollution, is short but very strong. Theme: General Session Presentation Type: Oral

P TREE-RING EVIDENCE OF WOOD PROPERTY CHANGES CAUSED BY MODERN ACIDIFICATION OF ARCTIC SOILS 1

2

2

3

4

Irina Panyushkina* , Alexi Grachev , Vladimir Shishov , Alexander Kirdynov , Eugene Chebykin , Eugene 3 1 1 Vaganov , Steven Leavitt , Malcom Hughes 1

LTRR University of Arizona, Tucson, USA Siberian Federal University, Krasnoyarsk, Russia 3 Sukachev Institute of Forest SBRAS, Krasnoyarsk, Russia 4 Limnological Institute SBRAS, Irkutsk, Russia 2

A number of studies show the damaging impact of acidification of the environment and soil, in particular, on the health of boreal forests. We hypothesize that wood formation would be sensitive to changes to the pH and availability of atmosphere-derived base cations in the soils. Larch tree rings from the Taimyr (72 N), Russia, were analyzed with inductively coupled plasma mass spectrometry (ICP-MS) to assess changes in wood


92

WorldDendro2014 Accepted Abstracts chemistry of these trees growing in a fairly pristine region. Forty-one tree-ring records were analyzed with cluster and principal component analyses to examine variance of the elemental composition of tree rings from 1300 to 2000 C.E. HYSPLIT atmospheric-trajectory modeling defined pathways of airflow that could deliver emissions to the site, originating regionally (the Norilsk Nickel facilities) and globally. Our tree-ring data indicate a steep decline in concentrations in wood of Ca and Mg, and upsurge in concentrations of K, Mn, Rb, Sr, Ba and P since ca. 1950. The trends are statistically significant and unprecedented for the last 700 years. A 3-fold reduction of Ca concentration in the wood is directly attributed to Arctic soil acidification. A ten-fold increase of K and P concentrations is likely a compensatory effect of the permafrost thaw driven by climate change. The profound variations in availability of primary nutrients may link to decline of tree health in Siberia. The low Ca-Mg and high K-P-Mn signal seen in the elemental concentrations of tree-ring records could be applicable to monitoring of soil chemistry for soil acidification and nitrogen depletion. Keywords: Biogeochemistry, Larix gmelinii, Air Pollution, Taymir, ICP-MS Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Oral CLIMATE, RIVERS AND THE FIRST FARMERS OF SEMIRECHYE IN CENTRAL ASIA 1

2

3

Irina Panyushkina* , Mark Macklin , Willem Toonen , Claudia Chang

4

1

LTRR University of Arizona, Tucson, USA Aberystywyth University, Aberystywyth, UK 3 Utrecht University, Utrecht, Netherlands 4 Sweet Briar College, Sweet Briar, USA 2

The Semirechye of Kazakhstan has been one of the primary loci of nomadic confederacy in Central Asia for the last 5000 years. Our new data on the Iron Age archaeology and Saka chronology show evidences of early farming and rapid changes in the size of the Saka population between 400 BC and AD 100. First farmers settled in the region not only would cause land-use diversification but also most importantly trigger the social complexity of the nomadic communities. We examined climate, river systems and Saka prehistory to understand the interplay between prehistoric people and environmental change driven by climate, particularly with respect to evolving arid-land farming. Correlation of well-dated Holocene fluvial chronology, pollen and tree-ring records from the Talgar fluvial fan (the foothills of Tian Shan Mountains) and other climatic proxies from the region suggest the intervals when the catchment hydrology may have significantly impacted early agricultural societies in the Semirechye. We discuss the significance of floating tree-ring records to dating control and integrating multi-scaled climatic proxies and fluvial chronology in our Talgar case study. From a broader perspective, better understanding of the socio-cultural processes underlying the ancient agropastoralist communities of Semirechye sheds light on a probable cultural response of the Central Asian nomads to the abrupt shifts of Late Holocene climate variability (including 4.2 ka, 3.8 ka and 2.6 ka events). Theme: S02. Civilisations, climate and tree rings Presentation Type: Oral TREE RINGS OF ROBLE (AMBURANA CEARENSIS (FR. ALLEM.) A.C. SMITH) AS INDICATORS OF PRECIPITATION AND TEMPERATURE CLIMATE AND POTENTIAL FOR CLIMATE RECONSTRUCTION 1

2

3

Kathelyn Paredes Villanueva* , Lidio Lopez , Matthew Brookhouse 1

Universidad Autonoma Gabriel Rene Moreno. Santa Cruz, Bolivia Ianigla/Cct-Conicet. Mendoza, Argentina 3 The Australian National University. Canberra, Australia 2

Knowledge of forest growth is particularly important in decision making processes in determining and evaluating sustainable forest harvesting cycles. In addition to facilitating the reconstruction of historical growth rates, the width and density of tree rings - annual layers of xylem tissue formed within the stems of woody plants - can reveal details on the factors affecting of an individual and ecosystem. Amburana cearensis (Fabaceae) - a species endemic to Bolivia, Perú, Ecuador, south-eastern Brazil and northern Argentina - is of *Indicates presenting author.

93

WorldDendro2014 Accepted Abstracts significance commercially and biologically. We aim to identify the potential of A. cearensis for climatological reconstruction and create a master tree-ring width chronology for A. cearensis to support dendrochronological studies of other Bolivian species. Sample materials for this study were collected from 11 A. cearensis within the Central Chiquitano Sector. The closest meteorological station is approximately 32km from the sample site. Once sample-level crossdating was complete, autoregressive modeling was performed to remove autocorrelation from the tree-ring series. We used ARSTAN to determine the chronology that best expressed the required signal. Standardized ring widths in A. cearensis correlated significantly with rainfall during November, December and April of the current growth year as well as May of the previous growth year. Inversely, correlations between the chronology and maximum temperature during April, May, October, November and December were significantly negative. No significant correlations were evident between minimum air temperature and tree growth index at monthly or annual scales suggesting, contrary to those of rainfall, that this variable is not suitable for climate reconstruction. Theme: O01. Tropical dendrochronology Presentation Type: Oral IS FIRE AN IMPORTANT FACTOR IN THE DISTRIBUTION AND OBSERVED DECLINE OF ASTELIA AUSTRALIANA IN THE COOL TEMPERATE RAINFORESTS OF SOUTHEAST AUSTRALIA? 1

1

1

1

Linda Parker* , Craig Nitschke , Sabine Kasel , Cristina Aponte , Tim Willersdorf

1

1

University of Melbourne, Melbourne, Australia

Astelia australiana, Tall Astelia (J.H. Willis) L.B. Moore is an endemic perennial typically associated with Cool Temperate Rainforest in Victoria. A. australiana was formerly more widespread but has undergone significant decline in its distribution and abundance leading to it being classified as Threatened under the Flora and Fauna Guarantee Act 1988 and Vulnerable under the Environment Protection and Biodiversity Conservation Act 1999. The current distribution of A. australiana is fragmented across the landscape with one population in the Otway Ranges in the west of Victoria and the other 14 in the Central Highlands. Fire is believed to be an important factor that has led to the decline in abundance and distribution of A. australiana since first being described in1929. Fire is also listed as a key process threatening the future viability of the species. In this study we are using standard dendrochronology methods to quantify the fire history of A. australiana at presence and known absence sites. Tree cores were sampled from Nothofagus, Atherosperma and Acacia species and analysed to determine the age class distribution to establish time since last fire. Preliminary results indicate that time since fire in the adjacent Wet Eucalyptus Forests is likely a stronger determinant of the species localised distribution. Theme: Z01. Other Presentation Type: Poster GROWTH AND CLIMATIC SENSITIVITY OF TREES IN THE TEMPERATE RAINFORESTS OF TURKEY AND THE REPUBLIC OF GEORGIA 1

1

2

2

Neil Pederson* , Dario Martin-Benito , Nesibe Kose , Tuncay Guner , Marine Mosulishvili

3

1

Tree Ring Laboratory of LDEO & Columbia University, Palisades, USA Istanbul University, Istanbul, Turkey 3 Illa State University, Tbilisi, Georgia 2

Anthropogenic climate change has had a considerable impact on many of the world's forests and these impacts are expected to continue. Literature review and new research is indicating that trees in almost all forest types are vulnerable to drought stress (reduced rainfall, increased heat stress, or a combination of both). However, the full impact of anthropogenic climate change is much less clear, especially in the diverse temperate broadleaf forests in humid to wet regions. For example, some studies indicate different species have different climatic thresholds and that different climatic variables influence growth of the same species in different regions. Here we report on initial investigations of dendrochronological characteristics, climatic sensitivity, and growth of four species in the Colchic temperate rainforests of Turkey and the Republic of *Indicates presenting author.

94

WorldDendro2014 Accepted Abstracts Georgia: Quercus petrea, Fagus orientalis, Quercus robur subspecies imeretina, and Zelkova carpinifolia. Two of these species, Quercus robur subspecies imeretina and Zelkova carpinifolia, are rare and have undergone little to no dendrochronological research. Even in urban and exurban settings, we found Quercus robur subspecies imeretina and Zelkova carpinifolia from 143-156 years of age. The oldest Quercus petrea of northeast Turkey are >240 years old. In general, radial growth of these species is limited by low precipitation during the early portion of the growing season and droughty conditions during the growing season, even those growing in an alluvial floodplain. These data show that trees growing in an environment of ~2000 mm of annual precipitation are likely to be significantly impacted during extended or extreme drought. Theme: Z01. Other Presentation Type: Poster DISTURBANCE, FOREST PRODUCTIVITY, AND GHOST TREES OF YEARS PAST: EARLY RESULTS FROM PALEON 1

2

3

2

4

Audrey Barker-Plotkin , Michael Dietze , Ana Camila Gonzalez , Jaclyn Hatala Matthes , Amy Hessl , Dario 3 3 5 3 6 Martin-Benito , Javier Martin Fernandez , Jason McLaughlin , Neil Pederson* , Ben Poulter 1

Harvard Forest, Petersham, USA Boston University, Boston, USA 3 Tree Ring Lab. of LDEO and Columbia University, Palisades, USA 4 West Virginia University, Morgantown, USA 5 Notre Dame University, South Bend, USA 6 Montana State University, Bozeman, USA 2

Forest structure, dynamics, and biomass are influenced by the legacy of past disturbance. Dendrochronology has the potential to reconstruct disturbance history to better understand the historical path of a particular forest. However, there are limitations in these data. Our understanding of how mortality events or natural thinning influence forests is limited because the tree-ring record might not fully capture all of the missing or ‘ghost trees'. In PalEON, we have developed a sampling protocol to partly address this issue. We are also exploring the uncertainties related to ghost trees by comparing tree-ring records to repeated measures from plots in the Harvard Forest (HF) established in 1969. Using a modeling approach, we will explore the biomass to sharpen sampling efforts. Of the two most important species in the HF plots, Acer rubrum experienced increased growth in the 1940s, a decline in the late-1960s, and reduced growth since the 1990s while Quercus rubra data contain only the 1940s event. Both species were impacted by gypsy moth defoliation in 1981. This event might have tipped the ecological balance in the favor of Quercus rubra. We compare the HF data to an older forest with a greater complexity in composition, age structure, and disturbance history, including a significant logging event in the late 1800s and an ice storm in the early 2000s. This comparison allows for insight into the role of disturbance and the long-term development of forests. These data and ecological analyses will give greater insight on how temperate forests sequester atmospheric carbon. Theme: Z01. Other Presentation Type: Poster DEEPER TIME, DEEPER DYNAMICS: TREE-RING INSIGHTS ACROSS A HUMID, TEMPERATE, BROADLEAF REGION 1

1

2

3

4

5

6

Neil Pederson* , Edward Cook , Naresh Devineni , James Dyer , Amy Hessl , Ryan McEwan , Cary Mock , David 7 1 8 Orwig , Richard Seager , Et. Al. 1

Lamont-Doherty Earth Observatory & Columbia University, Palisades, USA City College of New York, New York City, USA 3 Ohio University, Athens, USA 4 West Virginia University, Morgantown, USA 5 Dayton University, Dayton, USA 6 University of South Carolina, Columbia, USA 7 Harvard Forest, Petersham, USA 8 Six Other Institutions, USA and Austria 2


95

WorldDendro2014 Accepted Abstracts An axiom in paleo research is that deeper histories reveal greater dynamics within the study system. Two investigations in broadleaf-dominated regions of the eastern US support this general rule of thumb. While temperate, broadleaf forests in humid regions are generally thought to be more stable at large spatial scales than those in semi-arid or boreal regions, we find that both the moisture availability and ‘natural’ disturbance are more dynamic between late 1500s and 1800s than what has been observed since the latter half of the 1900s. A new reconstruction of the Palmer Drought Severity Index in the northeastern US indicates that the 16th century megadrought appears to have been more persistent than in regions to the south. In combination with reconstructions derived from the North American Drought Atlas, we also find a broad pattern of increasing wetness from ca 1840 to the 1980s. Similarly, tree-ring and independent recruitment data indicate coherent, regional to subcontinental forest dynamics. These two data sets reveal several important aspects in the dynamics of temperate, broadleaf forests. First, it supports data sets covering the Holocene that indicate climate as an important shaper of these forests. Second, it bridges the mesoscale gap between observational studies and sediment core to give a better understanding the continuous nature of disturbance at various temporal and spatial scales. Third, it gives insight into how these forests might rapidly change under future climate change scenarios. Finally, it indicates that episodic climatic events have long-lasting impacts on forests dominated by gap dynamics. Theme: O08. Drought and mortality Presentation Type: Oral TREE RING-DATED FLUCTUATION HISTORY OF MIDUI GLACIER SINCE THE LITTLE ICE AGE IN THE SOUTHEASTERN TIBETAN PLATEAU 1

2

3

Xu Peng* , Zhu Haifeng , Shao Xuemei , Yin Zhiyong

4

1

Geography and Planning School, Sun Yat-sen University, Guangzhou,China Institute of Tibetan Plateau Research, CAS, Beijing,China 3 Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing,CHN 4 University of San Diego,San Diego, USA 2

Fluctuation history of Midui glacier in the southeastern Tibet since the Little Ice Age (LIA) was reconstructed by the dating of lateral and terminal moraines using tree rings. Four conversions of glacier advance/stabilization to retreat were identified at around 1767, 1875, 1924 and 1964. The glacier reached its LIA maximum position at 1767. The fluctuations are consistent with those of other glaciers from the Tibetan Plateau, the Rockies and the Alps, suggesting high spatial coherency of glacier fluctuations in the Northern Hemisphere. Comparison with the summer temperature reconstruction in the southeastern Tibetan Plateau indicated that the Midui glacier fluctuation may be related to temperature variation on the centennial timescale. On the decadal scale, the fluctuation could correspond to cold/warm variation with an 8-year lag on average. Theme: General Session Presentation Type: Oral IS LATEGLACIAL/EARLY HOLOCENE CLIMATE VARIABILITY REFLECTED IN ANNUALLY RESOLVED TREE-RING STABLE ISOTOPE CHRONOLOGIES FROM CENTRAL EUROPE? 1

1

2

3

2

2

Hagen Pieper* , Achim Brauer , Klaus-Felix Kaiser , Cecile Miramont , Daniel Nievergelt , Ulf Buntgen , 1 Gerhard Helle 1

GFZ German Research Centre for Geosciences, Potsdam, Germany Swiss Federal Research Institute WSL, Birmensdorf, Switzerland 3 Institut Mediterraneen d'Ecologie et de Paleoecologie,Aix-en-Provence,France 2

To date ice cores and varved lake sediments possibly provide the best available proxy records for the Lateglacial/Early Holocene period. This includes the so-called Younger Dryas interval (ca.12.900 - 11.500 BP), representing an abrupt return to glacial-like conditions interrupting the transition to the warmer climate conditions of the Holocene. Lateglacial and Early Holocene tree-ring chronologies are rare, however, they are *Indicates presenting author.

96

WorldDendro2014 Accepted Abstracts of utmost importance for the calibration of the 14C calibration curve. They may also contain valuable information about past environmental conditions at annual time resolution. As the existing Latelacial tree-ring material is characterized by rather short segment lengths (mean tree age 140 yrs) in tree-ring width may not be the best parameter for assessing climate anomalies. Carbon and oxygen isotope composition of tree-ring cellulose has proven potential for climate reconstruction. Besides correction of short juvenile trends isotope data can be used with only minor adjustments to their means and sample depths of 4-5 trees are normally enough for a significant expressed population signal. We are investigating a floating 860-year (13200 - 12340 cal BP) dendrochronological record of Lateglacial and Early Holocene chronologies of scots pine (Pinus sylvestris L.) from subfossil tree remnants of Central Europe. Namely, from Barbiers River (Moyenne Durance, Southern French Alps) and three Swiss (Dattnau, Landikon and Ganziloh) sites. We will present and discuss our tree ring stable isotope records (δ13C und δ18O) in comparison to lake sediment and ice core data records. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral

Q DROUGHT VARIABILITY AT THE NORTHERN FRINGE OF THE ASIAN SUMMER MONSOON REGION OVER THE PAST MILLENNIA 1

1

1

1

Bao Yang , Shuyuan Kang , Minhui He , Chun Qin* 1

Cold and Arid Regions Environmental and Engineering Research Inst. lanzhou China

The northern fringe of the Asian summer monsoon region (NASM) in China refers to the most northwestern extent of the Asian summer monsoon. It is important to understand the characteristics and related mechanisms of drought variability at longer and shorter time-scales, because water shortage in the region is of great concern today and in the future. Here, we used newly developed and existing tree-ring, historical documentary and instrumental data available in the region to identify spatial and temporal patterns, and possible mechanisms of drought variability, over the past two millennia. We found that drought variations were consistent in the western (the Qilian Mountains and Hexi Corridor) and eastern parts of the NASM (the Great Bend of the Yellow River region) on decadal to centennial timescales. We suggest that the warm temperature anomalies in the tropical Pacific might have been mainly responsible for the recent 1975-1999 drought. A possible reason for the drought of 1625-1644 is the combined effects of the weakened Asian summer monsoon and an associated southward shift of the Pacific Intertropical Convergence Zone. This resulted from the combined effects of the Tibetan Plateau cooling together with the cooling of most of the Northern Hemisphere, rather than changes solely in the sea surface temperature of the tropical Pacific. Our results provide a benchmark for comparing and validating general circulation model paleosimulations of the variability of the Asian summer monsoon at decadal to centennial time-scales. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Poster RADIAL GROWTH OF QILIAN JUNIPER ON THE NORTHEAST TIBETAN PLATEAU AND POTENTIAL CLIMATE ASSOCIATIONS 1

1

Chun Qin* , Bao Yang 1

Cold and Arid Regions Environmental and Engineering Research Inst. lanzhou China

There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110-2011. The


97

WorldDendro2014 Accepted Abstracts main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation, and poor tree radial growth is particularly linked to the occurrence of serious drought events. The conclusion is that water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. At the treeline in this region, this finding contradicts any generalisation that tree-ring chronologies from treeline environments are mostly indicators of temperature changes. Theme: Z01. Other Presentation Type: Poster

R 50 YEARS OF METHODOLOGICAL DEVELOPMENT: THE MORE THINGS CHANGE, THE MORE THEY STAY THE SAME? 1

Meritxell Ramirez-Olle* 1

The University of Edinburgh, Edinburgh, United Kingdom

Day-to-day activities through which dendrochronologists generate and analyse tree-ring data have changed dramatically over the last fifty years with the introduction of more powerful and affordable equipment. The thesis of this presentation is twofold. Firstly, despite all these methodological gains, the fundamental procedures involved in crossdating have remained the same. At its most basic level, I maintain that counts and comparisons are the two main cognitive activities (that means, procedures of acquiring knowledge) involved in determining the total number of rings and ensuring their accurate dating. Counts are involved in the provisional enumeration of tree-rings present in individual samples and comparisons between rings from different samples are carried out in order to detect potential missing or extra rings. Crossdating is a complex task and this presentation will outline the exact steps carried out to achieve it. Precisely, the second part of the thesis of this presentation is that methodological innovations have occurred at the level of the execution of these routine steps and not at the overall guiding procedures (counts and comparisons). The results presented here are the result of a period of two years of research by a sociologist interested to understand dendrochronology. This involved observation of the routine activities of a group of dendroclimatologists in Scotland as well as some first-hand experience in crossdating. This talk may be of interest to practitioners willing to get some distance from the highly fragmented discussions in the field and who are looking for a unified account of past and present methodological developments. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral MODERN ACACIA SSP. IN SOUTHERN ISRAEL - VERIFYING DENDROCHRONOLOGICAL AGES BY RADIOCARBON DATING, AND CLIMATE-SENSITIVITY THROUGH THE MEASUREMENTS OF RING WIDTHS 1

1

2

3

Lior Regev* , Valentina Caracuta , Itzhak Moshe , Gidon Winters , Elisabetta Boaretto

1

1

D-REAMS Radiocarbon Laboratory, Weizmann Institute of Science, Rehovot, Israel Keren Kayemeth LeIsrael - Jewish National Fund, Southern Area, Israel 3 Dead Sea-Arava Science Center, Central Arava Branch, Israel 2

The southern region of Israel - the Negev desert - has a very poor vegetal cover. Among the limited species of trees, Acacia ssp. is the most common one. Here we report the results of dendrochronological and dendroclimatological analyses carried out on several Acacia raddiana and Faidherbia albida trees from arid (Negev and Arava) and sub arid (Judean hills) regions, where modern specimens were sampled. Since ring counts of Acacia ssp. is somewhat problematic, the measurements were verified using radiocarbon dating of the extracted cellulose fractions. Consequently, ring widths were measured and correlated to rainfall data from the nearby meteorological stations, in order to determine whether the local Acacia ssp. trees can be used


98

WorldDendro2014 Accepted Abstracts as dendroclimatological proxies. The results are then compared to data from Pistacia atlantica trees from the same geographical areas (Negev and Judean hills). Theme: O11. Tree rings and radiocarbon Presentation Type: Oral A PRELIMINARY 600-YEAR SUMMER TEMPERATURE RECONSTRUCTION FOR THE SCOTTISH HIGHLANDS 1

2

3

Milos Rydval* , Neil J. Loader , Bjorn Gunnarson , Rob Wilson

1

1

School of Geography and Geosciences, University of St Andrews, St Andrews, UK Department of Geography, Swansea University, Swansea, UK 3 Bert Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden 2

In order to fill a spatial and temporal gap in our understanding of climate dynamics in northwest Europe, thus providing the context for assessing future climate change in this important North Atlantic region, we present a preliminary 600-year reconstruction of Scottish summer temperatures using a network of ~50 living Scots pine tree sites and lake-derived subfossil samples from the Highlands of Scotland. This reconstruction represents the first significant dendroclimatological research for this region since Hughes et al., (1984). While using a combination of ring-width (RW), maximum latewood density (MXD), and Blue Intensity (BI) data, it represents an improvement in terms of temporal extension (using a larger number of sites and greater amount of data), as well as the utilisation of more advanced methodological approaches, including the application of detrending methods such as signal free detrending to capture a greater amount of multi-centennial variability than the earlier work. While the MXD and BI parameters respond mainly to July-August mean temperature, RW responds to a wider (previous December-August) seasonal window. By using a variety of approaches, preliminary calibration r2 results with July-August temperature range from 0.40 to 0.55. Cold periods during the so-called Little Ice Age are reconstructed from 1460-1530, 1570-1720 and 1780-1820. A notable reconstructed warm period in the mid 19th century possibly represents a 'release' bias related to widespread felling during and after the Napoleonic wars. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral DETECTION AND REMOVAL OF DISTURBANCE TRENDS IN TREE-RINGS FOR DENDROCLIMATIC PURPOSES 1

2

3

Miloš Rydval* , Kevin Anchukaitis , Daniel Druckenbrod , Rob Wilson

1

1

University of St Andrews, St Andrews, UK Woods Hole Oceanographic Institution, Woods Hole, MA, USA 3 Rider University, Lawrenceville, NJ, USA 2

We present an approach for assessing and improving the utility of ring-width (RW) data for dendroclimatic purposes from trees living in closed canopy woodlands by utilising methods which help to detect and remove anomalous growth pulse-trends related to disturbance. Focusing primarily on RW data from an extensive network of living Scots pine tree sites from the Scottish Highlands, a site-by-site assessment was performed using the Vaganov-Shashkin-lite (VS-lite) tree growth model to gain an understanding of the factors determining growth. The agreement and disparity between high and low frequency components of actual and modelled growth based on temperature and precipitation data were analysed to assess which sites expereinced significant non-climatic related trends. Sites exhibiting significant disagreement were further investigated using the combined step and trend (CST) intervention detection method. By applying CST, a series of non-climatic events (likely related to anthropogenic management and disturbance) were identified over multiple sites over the last ~300 years. The CST method was also used to 'correct' mid-frequency non-climatic signatures, in some cases leading to an improvement in the agreement between RW and instrumental data, and as indicated by re-assessing the corrected chronologies using VS-lite. The possibility of objectively removing non-climatic trends from tree-ring data to improve the palaeoclimatic potential of data from affected sites, as demonstrated in this work, could provide a useful tool for facilitating the development of climate reconstructions in locations where it would otherwise be difficult or impossible. *Indicates presenting author.

99

WorldDendro2014 Accepted Abstracts Theme: O03. Methodological challenges in dendrochronology Presentation Type: Poster

S RADIOCARBON DATING OF JAPANESE TREE RINGS FROM 4C TO 7C AD IN COMPARISON TO ARCHAEOLOGICAL CHRONOLOGY 1

2

3

4

Minoru Sakamoto* , Takumi Mitsutani , Takeshi Nakatsuka , Hiromasa Ozaki 1

National Museum of Japanese History, Sakura, Japan Nara National Research Institute for CUltural Properties, Nara, Japan 3 Nagoya University, Nagoya, Japan 4 University of Tokyo, Tokyo, Japan 2

The IntCal calibration curve is commonly used for calibrating radiocarbon dates of the northern hemisphere to calendar age. However, recent advances in accuracy of AMS radiocarbon measurement reveals that the resolution of IntCal may be insufficient for precise calibration. In particular, regional effect on the calibration curve turned out to be a major problem. AMS radiocarbon dating of Japanese wood unearthed at Nagano Pref., central Honshu Island with dendrochronological absolute age was carried out. Although this sample was already dated 10 years ago, the results were much improved in measurement error. Anomalous offsets from IntCal can be found in a Japanese tree - ring around AD500 and the middle of 7th century AD. The latter coincides with the calibrated age of plant remains in wall clay of Naniwa-no-Miya palace, Osaka, Japan established in about AD651. And the former explains well that the human bone excavated in tombs of the southern Korean peninsula agrees well with archaeological observations, suggesting that this anomaly might be extended in East Asia. Another radiocarbon dating of Japanese wood of the same period is ongoing to support these offsets from IntCal. Theme: O11. Tree rings and radiocarbon Presentation Type: Oral HYDROCLIMATE VARIABILITY ACROSS THE HIMALAYA INFERRED FROM A TREE-RING NETWORK OF OXYGEN ISOTOPE CHRONOLOGIES 1,2

Masaki Sano* , Takeshi Nakatsuka

1,2

1

Graduate School of Environmental Studies, Nagoya University, Japan Japan Research Institute For Humanity and Nature, Japan

2

We developed a tree-ring δ18O network composed of 5 sites across the Himalaya. Sampling was conducted at one site in Bhutan, three sites in Nepal, and one site in India. We selected 2-4 trees for each site for isotopic analysis. Tree-ring cellulose δ18O values were individually determined for each tree over the past 50-250 years. Our δ18O chronologies show significant negative correlations with local precipitation, relative humidity and/or the PDSI in the summer monsoon season, indicating that the tree-ring network can be used to investigate spatiotemporal variations in monsoon intensity. The first principal component derived from all the 5 chronologies for the past 50 years accounts for 49% of the total variance, with all positive PC loadings, reflecting mean precipitation across the Himalaya. On the other hand, the 2nd PC that accounts for 22% of the total variance shows a notable west-east contrast in PC loadings, i.e., positive (negative) for western (eastern) regions, indicating that intra-seasonal oscillation characterized by active and break monsoon may produce a quasi west-east precipitation dipole. Interestingly, at decadal to centennial scales, tree-ring δ18O chronologies also show opposite phases between western and eastern regions. A centennial-scale alternating modality of the intra-seasonal oscillation (in which active or break dominant) is possibly responsible for the contrasting phase variations between western and eastern regions.


100

WorldDendro2014 Accepted Abstracts Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral SPRUCE TREE-RING CARBON AND NITROGEN ISOTOPES COMBINED TO LOOK AT PAST POLLUTION IN NORTHEASTERN ALBERTA 1

1

1

Martine Savard* , Christian Begin , Joelle Marion , Anna Smirnoff

1

1

Geological Survey of Canada, Quebec, Canada

In northeastern Alberta (Canada), the NOx and SO2 emissions from the Lower Athabasca Oil Sands (OS) district, and power plants (PP) started in 1967 and 1956, respectively. However, the direct air quality monitoring has only been initiated in 1997 and 1985 in these respective contexts. In an attempt to address the gap in emission and deposition monitoring, we developed a retrospective approach combining long d13Cd15N series and response-to-climate modeling. We produced d13C and d15N series extending from 1880 to 2010, using Picea glauca and Picea mariana trees growing in four stands in the OS district and one, in the PP area. The intermediate and long-term d15N series did not vary significantly for two stands with poor soil drainage. The d13C and d15N trends inversely correlated in the three other stands, and statistical analyses for the pre-operation calibration periods (1910-1961 and 1900-1951) allowed developing transfer functions and predicting the natural d13C and d15N responses to climatic conditions for the operation periods. The measured series all depart from the modeled natural trends, depicting anomalies which can be nicely reproduced by multiple-regression models combining local climatic parameters with acidifying emissions. Our preliminary interpretation is that the concomitant SO2 and NOx inputs to the studied sites generated effects in the foliar and root systems, possibly lower stomatal conductance and increased ectomycorrhizal activities. The approach tested here in two distinct diffuse pollution contexts permits to define objective criteria for interpreting anthropogenic impacts on local air-soil-plant C and N cycles. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral ENSO FLAVORS IN A TREE-RING δ18O RECORD OF TECTONA GRANDIS FROM INDONESIA 1

2

Karina Schollaen* , Christina Karamperidou , Gerhard Helle

1

1

Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, 5.2 Climat Department of Meteorology, University of Hawai'i at Manoa, Honolulu, Hawai'i, US

2

The area surrounding Indonesia plays a key role in the global climate system because of the enormous heat and moisture exchange that occurs between the ocean and atmosphere. The climate in Indonesia is dominated by the equatorial monsoon system and has been linked to El Nino-Southern Oscillation (ENSO) events, which often result in extensive droughts and floods over the Indonesian archipelago with profound impacts on the populations of that region. Here, we evaluate the influence of rainfall variability on a 108-year long (19002007) tree ring δ18O record from teak (Tectona grandis) trees growing in a lowland rain forest in Central Java, Indonesia. We assess the potential of annually resolved oxygen (δ18O) isotope records to improve our understanding of the Asian monsoon variability. Climate response analysis with regional, monthly rainfall data reveals that the tree ring δ18O record is significantly correlated to rainfall and reveals dry and rainy season signals. Further, we investigate ENSO-related signals in the tree-ring δ18O record. Our study reveals a clear influence of Central Pacific ENSO events, while no clear signal of Eastern Pacific (canonical ENSO) events can be detected. These results are consistent with the distinct precipitation teleconnections of the two ENSO flavors in that region, and illustrate the importance of considering ENSO flavors when interpreting paleo-climate proxy records in the tropics. Previous work by the authors has identified key locations that could provide paleoclimate records able to distinguish between the two ENSO flavors. The results presented here demonstrate the applicability of tree-ring stable isotope records for this special purpose. Theme: O01. Tropical dendrochronology Presentation Type: Poster


101

WorldDendro2014 Accepted Abstracts SPATIOTEMPORAL MOISTURE VARIABILITY OVER THE FENNOSCANDIAN REGION SINCE A.D. 1400 1

2

1

Kristina Seftigen* , Edward R. Cook , Jesper Bjorklund , Hans W. Linderholm

1

1

Gothenburg University Laboratory for Dendrochronology GULD, Department of Earth Tree-Ring Laboratory, Lamont-Doherty Earth Observatory, Columbia University, U.S

2

The most prominent feature of an anthropogenic climate change will likely be related to changes in the precipitation pattern, and thus the frequency, duration, and intensity of droughts and pluvials. To be able to assess possible implications of such a change, firm knowledge about past natural moisture variability is needed. This includes an understanding of both the temporal nature and spatial characteristics of extreme moisture events, and the factors that are controlling them. Data from trees growing under tough climatic conditions can be used as a powerful proxy for past climatic events, such as drought. However in temperate Fennoscandia, where rainfall is abundant and summers are cool, tree-ring width and maximum latewood density chronologies are almost exclusively focused on past temperature variations. Consequently, comparatively few efforts have been made to provide tree-ring based hydroclimatological reconstructions for these regions. This study presents the first spatial reconstruction of past moisture variability for the Fennoscandian region. Fields of warm-season Standardized Precipitation Evapotranspiration Index, at a 0.5°cell resolution, were reconstructed back to A.D. 1400, from a densely distributed network of moisturesensitive tree-ring chronologies. The reconstruction placed the hydroclimatology of Fennoscandia in a longterm perspective, and helped to identify major drought and pluvial phases across the region. The relationship between spatial patterns of 20th-century droughts and pluvials and atmospheric circulation was assessed in order to understand the driving mechanisms behind moisture variability in the region. Historical drought and pluvial patterns were examined and the role of the circulation over time was assessed. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral MULTI-PERSPECTIVE COMPARISON FOR TREE RINGS δ13C VARIABILITY: A CASE STUDY OF PINUS SYLVESTRIS VAR. MONGOLICA FROM THE COOL TEMPERATURE REGION IN CHINA 1

1

Zhiyuan Shang* , Jian Wang* 1

College of Geographical Science, Nanjing Normal University, Nanjing, P.R.China

Stable isotopes in tree rings are being used in global change research and the majority is restricted to the stable isotopes of carbon, the easiest and most rapid development. Proper choices in collection and analysis for tree ring isotope studies will optimize utilization of resources and increase the certainty of resulting conclusions (Leavitt 2010). In view of this, it is necessary to perform multi-perspective comparison of following variability of tree ring carbon isotope ratio (δ13C) for a single species in the same area: among trees (individual), among orientations (circumferential) and tree heights (vertical) in a single tree, intra-annual variability (earlywood and latewood) and among components (δ±-cellulose, holocellulose and wholewood). Based on tree ring δ13C data of Pinus sylvestris var. mongolica discs sampled from cool temperature region in China, the above comparisons are performed. The result indicates that there are significant differences with varying degrees in each perspective of tree ring δ13C sequences. The variation amplitudes are greatest for individual, then relative greater for intra-annual and orientation and smaller for component and height in term of standard deviation. From the view of test statistics, the difference among individuals is the most significant, components the second. The circumferential difference is more significant than the corresponding interannual and the vertical difference is closely related to the corresponding inter-annual. The variance analysis shows that the differences in all above perspectives are almost at the same order of magnitude and should be taken into consideration in paleoclimatical or paleoenvironmental research deliberately. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral VERTICAL VARIABILITY OF PINUS SYLVESTRIS VAR. MONGOLICA TREE RING δ13C AND ITS RELATIONSHIP WITH TREE RING WIDTH IN THE COOL TEMPERATURE REGION OF NORTHEAST CHINA *Indicates presenting author.

102


1

1

4

Zhiyuan Shang* , Jian Wang* , Wen Zhang, Yanyan Li , Mingxing Cui, Zhenju Chen , Xingyun Zhao

5

1

College of Geographical Science, Nanjing Normal University, Nanjing, P.R.China College of Information, Shanxi Agricultural University, Shanxi, P.R.China 3 Northeast Institute of Geography and Agroecology, CAS, Changchun, P.R.China 4 Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, P.R.China 5 College of Resources and Environment, Linyi University, Shandong, P.R.China 2

A measurement was made on the vertical direction tree ring stable carbon isotope ratio (δ13C) and tree ring width of two Pinus sylvestris var. mongolica trees in the cool temperature region of northeast China, with the relationship between the vertical direction variations of the tree ring δ13C and tree ring width analyzed. In the whole ring of xylem, earlywood (EW) and bark endodermis, the δ13C all exhibited an increasing trend from the top to the base at first, with the maximum at the bottom of tree crown, and then, decreased rapidly to the minimum downward. The EW and latewood (LW) had an increasing ratio of average tree ring width from the base to the top. The average annual sequence of the δ13C in vertical direction had an obvious reverse correspondence with the average annual sequence of tree ring width, and had a trend comparatively in line with the average annual sequence of the tree ring width ratio of EW to LW above tree crown. The variance analysis showed that there existed significant differences in the sequences of tree ring δ13C and ring width in vertical direction, and the magnitude of vertical δ13C variability was basically the same as that of the interannual δ13C variability. The year-to-year variation trend of the vertical δ13C sequence was approximately identical. For each sample, the δ13C sequence at the same heights was negatively correlated with the ring width sequence, but the statistical significance differed with tree height. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Poster ANOTHER 3000-YEAR RING-WIDTH CHRONOLOGY FROM THE NORTHEASTERN TIBETAN PLATEAU, CHINA 1

1

1

Xuemei Shao* , Mingqi Li , Yong Zhang , Zhi-Yong Yin

2

1

Institute of Geographical Sciences & Natural Resources Research, Chinese Acad Marine Science & Env. Studies, University of San Diego, CA 92110, USA

2

In 2003 and 2004, two ring-width chronologies of approximately 2500 years long were published for the northeastern Tibetan Plateau. Both series were based on living, relic and archaeological samples from Dulan, Qinghai Province. In 2010, the first ring-width chronology of 3000+ years in China was constructed in Delingha, Qinghai Province. Similar to the above-mentioned Dulan chronologies, the earlier portion of this chronology was also based on archaeological samples from ancient tombs. Here we report another chronology of 3000+ years from Wulan of Qinghai Province, approximately 120 km northeast of Dulan. The difference between this chronology and the others is that all the samples are from living and relic trees at lower elevations, without any contribution from the archaeological wood. The Wulan chronology covers the period 1388 BC - AD 2012. At 1000 BC, there were 7 samples from 4 trees and the sample depth increased to 64 cores from 34 trees in AD 1. A common issue for chronologies based on archaeological samples in this region is the low sample depths during AD 600-900. For example, the Dulan chronologies had as low as 2 cores and the Delingha chronology had only 10+ cores during AD 600-900, while the sample depth of the new Wulan chronology reached 90 cores during this period. Good sample replications will allow us to reconstruct climate variation during the past 2500-3000 years with high confidence, while the combination of these long records makes it possible to reconstruct regional climate changes. Theme: General Session Presentation Type: Oral VS-MODELING AND ITS APPLICATIONS IN WOOD ANATOMY 1

1

Vladimir V. Shishov* , Ivan I. Tychkov , Victor A. Il'in


1

103


Siberian Federal University, Krasnoyarsk, Russia

Generally different dendroecological studies assume that annual tree-ring growth is adequately determined by a linear function of local or regional precipitation and temperature with a set of coefficients that are temporally invariant. However, various researchers have stressed that tree-ring records are the result of multivariate, often nonlinear, biological and physical processes (Fritts, 1976; Vaganov et al., 2006; Anchukaitis et al., 2006; Evans et al., 2006; Touchan et al., 2012). The process-based VS (Vaganov-Shashkin) model (Vaganov et al., 2006) can be used to resolve the critical processes linking climate variables to tree-ring formation (Touchan et al., 2012). New visual approach of VS-model parameterization (so-called VSoscilloscope) is developed which allows to simulate tree-ring growth and can be used by individual researchers and students (Tychkov et al., 2012). Seasonal tree-ring growth features (growing season duration, start date of growing season, number of days in growing season controlling by specific climate factor, etc.) were obtained for different regions: Siberia, Central Asia and Mediterranean Africa. Bi-modal growth patterns are obtained in Central Asia and Mediterranean Africa. To better understand the seasonal cell production and to verify the VSmodel findings a multiyear natural field studies (in specific regions) should be done, including seasonal observation of cell dynamics and cell dimension measurements. In the closest perspectives VS-Growth Evolution Neural Network (fully automatic parameterization algorithm based on specific genetic IT-approach ) will be developed which allows to estimate optimal tree-ring growth parameters around the Northern Hemisphere Dendro Network. Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Oral SEASONAL GROWTH AND STRUCTURE OF THE TREE RINGS: THE FORWARD MODELING AND RECONSTRUCTION 1

Eugene A. Vaganov , Vladimir V. Shishov*

1

1

Siberian Federal University, Krrasnoyarsk, Russia

Two approaches to the analysis of seasonal growth of tree rings are compared: a) relatively straightforward approach , based on V-S model, and b) inverse approach, in which the cell structure is used to reconstruct the seasonal dynamics (growth rate) of annual growth of rings. To compare the selected Scots pines(Pinus Sylvestris) growing on sandy soil area of the southern forest steppe in the south of the Krasnoyarsk Territory, under conditions of temperature limiting (beginning of the growing season, the initiation of cambial growth) and moistening (during the second half of the growing season). Alternate straightforward and inverse designs are examined for the annual rings of different widths (different cell production), and the causes of discrepancies between the straightforward and inverse are analyzed. In general, the presented approach can serve a good testing tool for the improvement of the V-S model and understanding the mechanisms that form the cellular structure of tree rings. Theme: O02. Measuring and modelling wood formation Presentation Type: Poster TREE-RING PROXY OF COMET IMPACTS 1

1

2

1

Oleg Shumilov* , Elena Kasatkina , Mauri Timonen , Alexander Kanatjev 1

Polar Geophysical Institute, Kola Science Center RAS, 184209 Apatity, Russia Finnish Forest Research Institute, Rovaniemi Research Unit, Rovaniemi, Finland

2

Using the results of the dendrochronological analysis (68 Siberian tree-ring chronologies) it has been shown earlier that the increase in the tree-growth after the 1908 Tunguska event is observed at a large distance (more than 1500 km) from the explosion site (61N, 102E). A similar, but smaller, result has been obtained when analyzing changes in the annual tree-ring growth after the Chulym bolide explosion (57.7N, 85.1E) in 1984. Here we present as well results of our analysis of Kola (northwestern Russia) and Scandinavian tree-ring records that also demonstrate the influence of 1873 Kola bolide impact on tree growth (up to 40% compared *Indicates presenting author.

104

WorldDendro2014 Accepted Abstracts to the previous year). In AD 536 an event occurred which caused significant climatic change. It seems to be caused by the collision with large cosmic body (larger than 500 m). Tree growth stress after the AD 536 event was analysed in detail using the 7500 supra-long chronology from Finnish Lapland. Our results indicate that the dendrochronological analysis can be applied to study the consequences of collisions with much smaller cosmic bodies with sizes ranging from several to hundred meters. The observation of these cosmic objects by using optical methods is most difficult as it was demonstrated in the case of the 2013 Chelyabinsk bolide. The results open new opportunities for using the dendrochronological method to solve the problems of the asteroidcomet danger (cataloguing of events, estimate of the trajectory and action region, etc.). Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Poster SIBERIAN TREES AS PALEO-THERMOMETERS OF WARMEST PERIODS ON THE EURASIAN NORTH 1

Olga Churakova (Sidorova) , Rolf Siegwolf*

2

1

ETH Zurich, Zurich, Switzerland PSI, Villigen, Switzerland

2

According to the Intergovernmental Panel on Climate Change report some aspects of the current climate change are not unusual, but others are. Therefore we need to look into the past for revealing œunusual anomalous (extremely warm) climatic changes. The application of long-term tree-ring chronologies (natural archive to study climatic changes) in paleoclimate reconstructions can help us to evaluate climatic and environmental changes in the past and to estimate the magnitude of the recent warming. Based on tree-ring width chronologies constructed for the eastern Taimyr (72°N, 102°E) extremely warm periods BC 4111-3806, AD 917-1150 which are characterized by low CO2 concentrations compared to the AD 1791-2008 were analyzed. We developed a description of the climatic and environmental changes on the eastern Taimyr using tree-ring width and stable isotope (Δ13C, Δ18O) data. Tree-ring widths, Δ13C and Δ18O in tree ring cellulose indicate that the period from BC 4111 to 3850 was warmer and drier than the recent period from AD 1791 to 2008. Tree-ring index and stable isotope data of the recent period show similarities with the period from BC 3906 to 3806. Significant agreements between stable carbon and oxygen isotope chronologies and July temperature, and precipitation reconstructions obtained from pollen data and ice core data revealed strong temperature and precipitation signals indicating warm and wet climatic conditions during the Medieval Warm Period (MWP). This work was supported by Marie Curie Fellowships (EU-ISOTREC 235122; 909122). Theme: O06. Stable isotopes in dendrochronology Presentation Type: Poster WHEN CONCEPTS OF STABLE ISOTOPES IN PLANT PHYSIOLOGY DO NOT GO ALONG OUR EXPECTATIONS 1

1

Rolf Siegwolf* , Matthias Saurer , 1

Paul Scherrer Institute, Villigen, Switzerland

The evaluation of isotopic variations in tree rings yields essential information on physiological responses to environmental changes, which is highly instrumental in the analysis and interpretation of tree ring data. Models on fractionation mechanisms for carbon and oxygen isotopes resulting from plant/tree physiological processes are well established. The carbon isotope discrimination model as widely used today, describes the role of photosynthesis and stomatal conductance on isotopic fractionations (δ13C) in C3-plants. The combination of the carbon and oxygen isotope ratios (δ13C and δ18O) from the same sample of plant organic material provides the link to long term CO2 and H2O gas exchange and the means to distinguish the effects of stomatal conductance and photosynthesis on the carbon isotope discrimination and plant water relations. This approach is successfully applied in stress physiology, air pollution studies, or to estimate to what degree elevated CO2 impacts the intrinsic water use efficiency of trees since the last 150 years. However, the application of the dual isotope approach is not always straight forward. Sometimes it can lead to non-plausible interpretations. This is mostly the case when plants were extremely stressed, like severe drought, frost, flooding, high N depositions or air pollution, in general for situations, where the plants survival was *Indicates presenting author.

105

WorldDendro2014 Accepted Abstracts endangered. A careful analysis of such unexpected results shows that either the carbon discrimination model is no longer valid or the assumptions for the leaf water enrichment are violated. The analyses, resulting from such discrepancies facilitate the understanding of the causality of the tree-environment interaction. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral GLACIER FLUCTUATIONS FOR THE PAST FOUR CENTURIES OVER THE WESTERN HIMALAYA, INDIA - AS EVIDENCED FROM TREE- RING STUDIES 1

Amarendranath B. Sikder* , Hemant P. Borgaonkar

1

1

Indian Institute of Tropical Meteorology, Pashan, Pune- 411008, India

An unprecedented enhancement in growth during the last few decades is detected in the 458 years long treering records of Himalayan cedar( cedrus deodara D. Don ) from the high altitude areas of Kinnor and Gangotri region of Western Himalaya, India. Dendroclimatological investigation indicates significant positive relationship of tree - ring index series with winter ( December - January - February) temperature and summer precipitation and inverse relationship with summer temperature. Higher growth in recent few decades detected in tree-ring chronology has been noticed coinciding with the rapid retreat of the Himalayan glaciers. Suppressed and released growth patterns in the tree-ring chronology have also been observed to be well related to the past glacial fluctuation records of the region. The higher and lower tree growth epochs in the tree-ring records have reasonably have been found to be coinciding to the various glacial fluctuation records. The enhanced and suppressed growths in some years during recent decades have significant correlations with negative and positive mass balance records respectively. An extensive dendroclimatic and dendroglaciological investigation over high altitude Himalayan region may be useful to enhance our knowledge on snow and ice processes and their relevance to climate in the high mountain ranges. Theme: O07. Dendrogeomorphology Presentation Type: Oral DYNAMIC TREE GROWTH RESPONSE TO CHANGING CLIMATIC AND HYDROLOGICAL CONDITIONS IN TEMPERATE FOREST 1

1

1

1

Sonia Simard* , Ingo Heinrich , Gerhard Helle , Theresa Blume , Andreas Guntner

1

1

German Research Centre for Geosciences GFZ, Potsdam, Germany

Atmospheric and soil hydrological conditions largely determine the water status of trees. Internal water regulation mechanisms, however, partially uncouple tree water status from these controls. We examine the water relation of trees from different functional types (conifer vs. deciduous), and with different wood anatomy (ring- vs. diffuse-porous), from the temperate forest growing along hydrological gradients. Mature Pinus sylvestris, Fagus sylvatica and Quercus petraea growing along transects stretching from lake shores to the top of a nearby hill are equipped with 30 point dendrometers and 24 sap flow sensors. Hydrological processes at the study site are also closely monitored. The presentation will show first results and discuss the mutual effects of stem water storage, transpiration, and growth, and their interaction with environmental conditions. This study is part of ongoing multi-disciplinary investigations on the impacts of hydrological changes, with decreasing water availability and increasing temperatures, on terrestrial systems, and was established within the framework of the Virtual Institute for Integrated Climate and Landscape Evolution Analyses (ICLEA.de) project focusing on the lowlands of NE-Germany, a region with high vulnerability with respect to climate change effects, in particular water scarcity. Theme: O02. Measuring and modelling wood formation Presentation Type: Oral TREE-RING: A SUITABLE IMPLEMENT FOR FIRE HISTORY RECONSTRUCTION IN SAVANNA WOODLAND AND DRY FOREST *Indicates presenting author.

106

WorldDendro2014 Accepted Abstracts 1; 2

1

3

Franck Sinsin* , Romain Lucas Glele-Kakai , Bettina Orthmann , Brice Sinsin

1

1

Laboratory of Applied Ecology Dendrochronology Lab, Goettingen, Germany 3 Laboratory of Biosciences, Rostock, Germany 2

Based on 120 stem discs collected during 3 months of fieldwork along 12 km route, the history of fires in the Wari Maro Forest over the past century in savanna woodland and dry forest was reconstituted. By analyzing tree rings, 246 fire scars were identified. The scars were concluded to come from 51 fire years, with a mean interval of 2.23 years between two consecutive fires occurrence. However, from 1890 to 1965, only six years with fires were recorded from sampled trees, but since 1966, there has been no year without fire. The fire frequency point scale reached 14 years. This was the case of Burkea africana, which has been identified as a species tolerant to fire and could be a potential species for a natural firewall. However, Anogeissus leiocarpa is a highly sensitive species to fire, and in a dry forest ecosystem, which is seasonaly burned, the species deserves to have a special conservation plan. Two new concepts were described: the rebarking of trees after experiencing fire and the Mean Kilometer Fire Interval. The first one was observed with Daniellia oliveri (Rolfe) Hutch & Dalz trees, and the second one has been used to evaluate the spatial fire distribution. We demonstrate that savanna woodland and dry forest were subject to a degradation process coming from destructive fires related to vegetation cover clearance due to illegal logging. Three major ecological areas were characterized: one highly burnt zone between two relative less burnt areas. Key words: Fire ecology, Treerings, Woodland, Dry Forest, Conservation strategies Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Poster THE AFRICAN BAOBAB - A HIGH-RESOLUTION ARCHIVE FOR CLIMATE VARIABILITY OF SEMI-ARID AFRICA? 1

1

2

Franziska Slotta* , Frank Riedel , Karl-Uwe Heubner , Gerd Helle

3

1

Freie Universitat Berlin, Berlin, Germany German Archaeological Institute, Berlin, Germany 3 German Research Centre for Geosciences, Potsdam, Germany 2

Prediction of the climate change impact on the African continent requires information about the past climate conditions preferably in high-resolution. However, there is a lack of trans-regional high-resolution proxy data. The African baobab, Adansonia digitata L., is widely distributed throughout semi-arid Africa. It has been revealed by 14C-dating to reach ages of 2000 years. The wood of this species can therefore be considered as a potentially important source of high-resolution palaeoclimatic information. We seek to evaluate the potential of baobab from different sites for crossdating and test the climate response of growth increments and of stable carbon and oxygen isotope ratios. Increment cores from two sites in Botswana (Kubu Island; 20°53' S, 25°49' E) and S-Africa (Musina; 22°17' S, 29°50' E) have been analysed. At the latter site climate variables (T, rH) and seasonal radial increment growth are monitored for a better understanding of the baobab's physiology. Ring-width measurements were done in WinDENDRO on accurately merged UV-light photos of the moist core samples from Kubu Island. By comparing ring width and precipitation data annual growth patterns could be identified. Although the results of stable isotope analysis revealed no clear relationship with tree-ring growth of the same year, the mean values of δ13C, δ18O and the tree-ring width chronology correlate significantly with climate data. We will present how increment cores can best be received from baobabs and prepared for tree ring analysis and discuss the potential of proxy data from baobab trees for future highresolution climate studies in Africa. Theme: O01. Tropical dendrochronology Presentation Type: Poster SPATIAL DISTRIBUTION OF NORWAY SPRUCE RADIAL GROWTH VARIABILITY IN HEAVILY POLLUTED ENVIRONMENT (THE SUDETES, POLAND)


107


2

2

2

Justyna Lisok , Maciej Kryza , Marek Blas , Michal Godek , Mieczyslaw Sobik*

2

1

University of Warsaw, Warsaw, Poland, University of Wroclaw, Wroclaw, Poland,

2

In the early 70s of the XXth century the Central Europe heavy industry was mainly based on the lignite combustion. This fact was responsible for emission of substantial amount of sulphur oxides into the atmosphere. The area located between the borders of Czech Republic, Germany and Poland has received a name the Black Triangle region. The exposition of the Sudetes to the prevailing south-western wind that carried heavily polluted marine air masses from the region was mainly responsible for the degradation of the forest ecosystems in 80s. In the most polluted area the reduction of the radial growth by about 60 percent was observed. The scale of phenomenon gives an opportunity to the complex studies on the air pollution influence in the mountainous forest ecosystems in the light of dendrochronological and spatial analysis tools. The aim of the research was to analyze the radial growth differentiation of mountainous Norway spruce (Picea abies) stands by means of spatial geographical cluster analysis. The samples were collected in the three areas, which were characterized by the different sulphur load (small, medium and high) in the period of 1970-2000. The terrain characteristics and meteorological data were taken into account as far as the geographical factors were concerned. Moreover, the total wet deposition of sulphur oxides from the EMEP model was used. The results proved a significant resemblance of the radial growth fluctuation and sulphur oxides spatial distribution pattern. The factors that modified the results were mainly: precipitation, elevation and the relief. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Poster HOW DOES THETREE RING GROWTH OF MONTANE NORWAY SPRUCE IN CENTRAL-EASTERN EUROPE RESPOND TO ATMOSPHERIC POLLUTION? 1

1

1

Mieczyslaw Sobik* , Marek Blas , Michal Godek , Piotr Owczarek

2

1

University of Wroclaw - Department of Climatology, Wroclaw, Poland University of Wroclaw - Department of Physical Geography, Wroclaw, Poland

2

The main goal of this study is to examine if the existing spatial differences in spruce growth dynamics are controlled in considerable extent by atmospheric pollutant deposition, which by itself shows large spatial and temporal variations. The field work was performed in Poland and the Czech Republic at 9 different locations along 400 km NW-SE profile in some mid-mountain ranges (namely: the Sudetes and the Beskidy Mts) with three separate sampling sites within each location: (a) lower subalpine forest zone in valley position, (b) upper subalpine forest zone with windward aspect, (c) upper subalpine forest zone with leeward aspect. Altogether around 1000 individual drilling cores have been collected and analysed. The achieved results indicate that ‘pollution tree rings' dependence really exists, moreover the largest reduction of tree rings width stems from direct deposition of polluted fog/cloud droplets i.e. at the windward slope within the upper subalpine forest. The most intense reduction of tree rings took place in the seventies and eighties of the previous century. Particularly interesting is the recently observed recovery of tree-ring dynamics in the context of strong parallel decrease in pollutant deposition for the last 20 years. On the other hand within the lower subalpine forest zone where pollutant deposition is controlled by precipitation instead of fog, the air pollution signal does not alter the spruce growth dynamics. In this forest zone the width of annual increments at spruce is related mainly to a given tree age rather than to pollutant deposition field. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral TRACKING DOWN THE AIR POLLUTION SIGNAL IN WOOD ANATOMY OF THE SUBALPINE NORWAY SPRUCE 1

2

2

3

Elbieta Myskow , Marek B , Michas‚ Godek , Piotr Owczarek , Mieczyslaw Sobik*

2

1

University of Wroclaw - Institute of Experimental Biology, Wroclaw, Poland University of Wroclaw - Department of Climatology, Wroclaw, Poland

2


108


University of Wroclaw - Department of Physical Geography, Wroclaw, Poland

The European mid-mountain ranges located on the Polish, Czech and Ukrainian territory are mostly covered by coniferous forests, which are damaged in large extent and present diverse defoliation rates. The forest impairment is related to the spatial and temporal variability of air pollution. In the context of changes in the atmospheric pollutant emission and deposition observed in last decades, it was particularly important to examine: (i) relationships between pollutant deposition rate and detrimental changes in the subalpine spruce ecosystems, (ii) whether and how these ecosystems come back to an equilibrium after an ecological disaster, (iii) whether and to what degree the local exceedance of critical loads of pollutants still affect the growth of spruce forests. The analyses of specific features of a secondary xylem within selected annual rings revealed the alterations of tree growth rate observed over large areas, which could be caused by the different environmental stresses of a natural and/or anthropogenic origin. However the presence of traumatic resin channels clearly corresponded to the periods, in which the forests were exposed to the intense pollutant deposition, impairing the tree growth and assimilation system by the damage of shoot apices (meristems) and upper branches. This correlation confirmed the usefulness of the dendrochronological methods in evaluation of extremely damaged stands with progressing crown thinning. Theme: O12. Quantitative wood anatomy of conifers Presentation Type: Poster MAY-JULY MEAN TEMPERATURE RECONSTRUCTION USING RING WIDTHS OF CHINESE PINE (PINUS TABULAEFORMIS CARR.) IN SHIMEN MOUNTAIN, CHINA SINCE AD 1630 1

1

Huiming Song* , Yu Liu* , Qiang Li

1

1

Institute of Earth Environment, Chinese Academy Of Sciences, Xi’an, China

Although considerable variations have been documented in tree-ring cellulose oxygen isotope ratios (delta 18Ocell) among co-occurring species, the underlying causes are unknown. Here, we used a combination of field measurements and modeling to investigate the mechanisms behind variations in late-wood delta 18Ocell (delta 18Olc) among three co-occurring species (chestnut oak, black oak and pitch pine) in a temperate forest. For two growing seasons, we quantified among-species variation in delta 18Olc, as well as several variables that could potentially cause the delta 18Olc variation. Our data analysis conducted within the framework of the tree-ring mechanistic model rules out canopy temperature (Tcan), the Péclet effect caused dampening factor f0, and tree-ring formation period (delta t) as important contributors to the measured among-species delta 18Olc variation, but highlights the role of source water delta 18O (delta 18Osw) in explaining the blackchestnut oak difference in delta 18Olc. In contrast, parameterization of the model with these empiricallydetermined variables could not explain the enriched delta 18Olc in pitch pine relative to the oaks. Through model-measurement comparison, we demonstrate that to sufficiently explain the pine-oak difference, the Péclet correction should not be used for pitch pine. Our finding of differential relevance of the Péclet effect to delta 18Olc for broad-leaved versus needle-leaved trees has implications for delta 18Ocell based ecophysiological/paleo-climate studies. Theme: Z01. Other Presentation Type: Poster INTERPRETING THE VARIATION IN TREE-RING OXYGEN ISOTOPE RATIOS AMONG THREE CO-OCCURRING SPECIES IN A TEMPERATE FOREST 1

2

Xin Song* , Ken Clark , Brent Helliker

1

1

Department of Biology, University of Pennsylvania, Philadelphia, PA, USA USDA Forest Service, Silas Little Experimental Forest, New Lisbon, NJ, USA

2

Ring widths from Chinese Pine (Pinus tabulaeformis Carr.) collected at Shimen Mountain of western Loess Plateau, China were used to reconstruct the mean May-July temperature spanning AD 1630-2011. The regression model explained 48% of the adjusted variance in the instrumentally observed mean May-July *Indicates presenting author.

109

WorldDendro2014 Accepted Abstracts temperature. The reconstruction revealed significant temperature variations at interannual to decadal scales. Cool periods occurred in the reconstruction coincided with reduced solar activities. The reconstructed temperature matched well with other two tree-ring based temperature reconstructions in the northern slope of Qinling Mountains (southern margin of China Loess Plateau) at both annual and decadal scales, it also could be well compared with several temperature series derived from different proxies as well. This reconstruction could contribute to the sparse network of high-resolution paleoclimatic records for the western Loess Plateau, China. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral PANDORA MOTH AS AN EXAMPLE OF A SPECIES-WIDE NETWORK FOR ANALYSIS OF INSECT OUTBREAKS 1

2

3

1

James H. Speer* , Kristen de Graauw , Dorothy J. Rosene , Stephen P. Aldrich , Vijay O. Lulla

4

1

Indiana State University, Terre Haute, USA West Virginia University, Morgantown, USA 3 University of Tennessee, Knoxville, USA 4 Indiana University, Bloomington, USA 2

In the western United State, pandora moth (Coloradia pandora) primarily feeds on the needles of ponderosa pine (Pinus ponderosa). Defoliation during an outbreak stresses the tree, leaving a distinct signature in the tree rings which can be used to determine the frequency of outbreaks across the insect's range. All 200 ponderosa pine chronologies from the International Tree Ring Databank (ITRDB) were examined for the ring-width signature of pandora moth outbreaks and those suppressions where compared to a network of nonhost treering chronologies from Douglas fir (Pseudotsuga menziesii), juniper (Juniperus spp), and oak (Quercus spp) for a climate control. We used Principle Component Analysis (PCA) to create a new PDSI grid in ArcGIS 10 and then we compared each ponderosa pine chronologies to the nearest non-host chronology within the grid to differentiate pandora moth outbreaks from climate events. This data was then used to create an animated map of pandora moth outbreaks through time which we used to examine spatial hypotheses of outbreak spread across the landscape. We also compared the outbreak data to a pandora moth outbreak hazards map that we created for the entire range of the insect using climate, soils, and host tree species to help verify the efficacy of our hazard model. This research is a potential model for how chronologies in the ITRDB can be used to examine hypotheses about species dynamics across the entire range of the species. With this broader spatial perspective, we can start to examine more landscape-scale dynamics that were previously inaccessible. Theme: O09. Insect outbreaks Presentation Type: Oral MESOAMERICAN DENDROCLIMATOLOGY AND SOCIAL CHANGE OVER THE PAST MILLENNIUM 1

David Stahle* , Jose Villanueva

2

1

University of Arkansas, Fayetteville, USA INIFAP, Gomez Palacio, Mexico

2

Megadrought has been implicated in pre-Conquest cultural decline at several pre-Hispanic city-states in Mesoamerica. However, the tree-ring record in Mesoamerica has not been long enough to extend back into the pre-Hispanic era to test hypotheses about climate and cultural change, or the internal and external forcing of climate variability over the region. We have developed two new millennium-long tree-ring chronologies for Mesoamerica at Barranca de Amealco, Queretaro, and on the Rio San Pedro Mezquital, Durango, using ancient Montezuma baldcypress trees (Taxodium mucronatum), which date from AD 771-2008 and 1075-2012, respectively. These chronologies have been used to reconstruct early growing season moisture conditions and indicate that the mid-12th century drought, the worst megadrought yet identified in the North America treering record for the past 1200-years, extended into central Mexico and was approximately contemporaneous with the decline of the Toltec capital of Tula. The new reconstructions indicate profound drought during the early 15th rise of the Aztec state and during the Spanish Conquest of Mexico during the early 16th century. *Indicates presenting author.

110

WorldDendro2014 Accepted Abstracts We have also developed a combined archaeological and modern tree-ring chronology for the large preHispanic site of Paquime near Casas Grandes, Chihuahua, dating from 850-2008. This record is based on Douglas-fir (Pseudotsuga menziesii) and pine (Pinus sp.) and includes chronologies of earlywood, latewood, and total ring width that provide excellent proxies of cool and warm season moisture variability over the past millennium. Theme: S02. Civilisations, climate and tree rings Presentation Type: Oral EXTENT, ABUNDANCE, AND AGES OF BURIED SUBFOSSIL TREES IN STREAMS OF THE CENTRAL U.S. 1

1

Michael Stambaugh* , Richard Guyette , Joseph Marschall

1

1

University of Missouri

Recent work recovering ancient trees (up to 22,000 years old) from streams flowing through the Central U.S. shows excellent potential for constructing long chronologies and documenting Holocene and late-Pleistocene climate and environmental changes. Subfossil trees are 'buried treasures' in that they describe plant growth and climate variability for a highly agricultural landscape. The geographic extent, abundance, and ages of this resource are largely unknown; however, based on extensive aerial and ground surveys throughout region, it is possible that the majority of higher-order streams contain wood with ages > 1000 years. We used aerial and ground surveys to describe the extent to which these ancient buried trees are distributed throughout major waterways. The most abundant and oldest wood was found in glaciated regions of Missouri and Iowa and these results are being used to guide the geographic focus of future wood collection efforts. Practical information related to aerial reconnaissance, and stream-wood dynamics will be discussed. Theme: General Session Presentation Type: Oral THE TRACE OF FIRE IN EASTERN NATIVE AMERICA 1

1

1

2

Michael Stambaugh* , Richard Guyette , Joseph Marschall , Daniel Dey , Rose-Marie Muzika

1

1

Missouri Tree-Ring Laboratory, University of Missouri, Columbia, USA U.S. Forest Service, Northern Research Station, Columbia, USA

2

Written in the rings of treesacross the eastern U.S. is a history of fire that tells of humans, drought, and their interactions. Based on thousands of fire scars on oak and pine trees, these quantitative fire histories move through generations and territories. Each fire scar has a date, location, and often an associated human population. We examined the connections between the occurrence of wildland firesand populations ofeastern Native Americansincluding the Cherokee, Chippewa, Osage, Menominee, and others. The geography of fire history sites includes Appalachia, the Great Lakes, the Great Plains, the Southeast, and the Midwest. Many fire regimes in eastern Native America are found to have a human 'footprint' reflected as atemporally abrupt or rapid change in fire frequency. These resultsstrongly implicate humans for the existence of historically frequent fire regimes. The significance of this point to futurefire and ecosystem management includes: 1) humans may be required for many frequent fire regimes to exist, and 2) historically fire-maintained vegetation communities were an artifact or construct of human influence. Theme: Z01. Other Presentation Type: Poster CLIMATE FIELD RECONSTRUCTION UNCERTAINTY ARISING FROM TREE RING WIDTH-LIKE PREDICTORS 1

2

2

3

4

Michael Evans , Jason Smerdon , Alexey Kaplan , Susan Tolwinski-Ward , J. Fidel Gonzalez-Rouco , Kaitlyn 1 Steele 1

University of Maryland, College Park, MD USA


111


Lamont-Doherty Earth Observatory, Palisades, NY USA National Center for Atmospheric Research, Boulder, CO USA 4 Ciudad Universitaria, Madrid, Spain 3

We perform pseudoproxy experiments using the mean annual surface temperature field from a millennial simulation of the GKSS ECHO-G general circulation model. Given a known target, the pseudoproxy framework permits us to isolate uncertainties arising from specific aspects of the paleoreconstruction process. In this study, global mean annual surface temperature (GMAT) and temperature fields are reconstructed using the following pseudoproxy datasets derived for realistic data masks and signal-to-noise ratios: (1) mean annual temperature; (2) 50%/50% by variance mean annual temperature and precipitation; (3) mean annual precipitation only; (4) soil moisture calculated by the CPC Leaky Bucket Model; and (5) synthetic tree-ring width variations based on VS (Vaganov-Shashkin)-Lite, a realistically nonlinear and multivariate proxy system model forced with monthly temperature and precipitation inputs. Preliminary results suggest that reconstructed GMAT timeseries and their spectral transforms are insensitive to multivariate/nonlinear proxy response, if at least some of the variance in the proxy system and/or proxy network is temperature-controlled. We examine the extent to which regional-scale uncertainty is dependent on proxy system complexity. The results will be used to illustrate and rank this source of uncertainty relative to those arising from observational error, observing network, and reconstruction algorithm that have been described in the literature. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral CORRECTION ALGORITHM FOR ON-LINE CONTINUOUS FLOW STABLE ISOTOPE ANALYSES 1

1

1

1

Michael Evans , Kaitlyn Steele* , Benjamin Breeden , Alex Lopatka , Rebecca Plummer

1

1

University of Maryland, College Park, MD USA

We describe an algorithm for correcting for scale compression, runtime drift, and amplitude effects in oxygen and carbon isotopic composition measured in two different online continuous flow isotope ratio mass spectrometry systems. We validate the algorithm by applying it to correction of measurements of samples of known isotopic composition which are independent of the basis for the corrections. For carbonate carbon (oxygen) isotope measurements, precision is 0.04-0.09 permil (0.04-0.21 permil); bias is less than 0.18 permil (0.08 permil) over a range of 41.0 permil (29.3 permil). For alpha-cellulose carbon (oxygen) isotope measurements, precision is 0.13-0.21 permil (0.31-0.37 permil); bias is less than 0.04 permil (0.19 permil) over a range of 13.3 permil (9.7 permil). The results suggest that validated correction for systematic error may enable CF-IRMS systems to produce analyses with higher precision, accuracy and throughput than typically reported for these systems. The correction scheme may be used in support of replication-intensive research projects in stable isotope dendroclimatology. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Poster LIGHT LIMITATION AND TREE-RING GROWTH IN THE SCHWEINGRUBER COLLECTION 1

1

Alexander (Zan) Stine* , Peter Huybers 1

San Francisco State University, San Francisco, USA Harvard University, Cambridge, USA

2

Reconstructions of surface temperature from Arctic tree rings sampled by the Schweingruber tree-ring collection underestimate temperature increases in many regions of the Arctic during the second half of the twentieth century. A physical understanding of this divergence is necessary for fully interpreting temperature reconstructions prior to the availability of instrumental temperature estimates. In general, the growth of Arctic vegetation is limited both by temperature and light availability, suggesting that variations in atmospheric transmissivity may also influence tree-ring characteristics. We test the hypothesis that light limitation influences tree-ring growth in high northern latitudes by analyzing the spatial patterns of tree-ring density *Indicates presenting author.

112

WorldDendro2014 Accepted Abstracts variability in high northern latitudes using the Schweingruber collection. We find that high-northern latitude tree-ring density is sensitive to changes in light availability across two distinct phenomena: explosive volcanic eruptions (P 500 years challenges the 350-450 year timeframe proposed by the traditional model of succession from eucalypt to rainforest. These forests not only store vast amounts of carbon, but also maintain high carbon densities for a long period of time. Estimates of the capacity of temperate forests to store carbon should consider past fire regimes and increased fire frequencies associated with climate change. Theme: Z01. Other Presentation Type: Poster VULNERABILITY OF TASMANIA SUBALPINE CONIFER RAIN FORESTS TO THE SYNERGISTIC EFFECTS OF HIGH SEVERITY FIRE AND HERBIVORE POPULATION IRRUPTION 1,3

1

1

Andres Holz , Sam Wood* , David Bowman , Thomas Veblen

2

1

University of Tasmania, Hobart, Australia University of Colorado, Boulder CO, USA 3 Portland State University, Portland OR, USA 2

In 1960-61, human-ignited wildfires during the driest spring-summer in record since 1935 to present, killed ca. 33% of the slow growing, Athrotaxis cuppressoides conifer rain forests. We collected dendrochonological, floristic and structural data to (a) provide a historical context for this large scale fire event (b) document the post fire survival and regeneration of Athrotaxis, and associated understory species recovery and (c) assess community flammability. We found that A. cupressoides survived low-to-mid- severity fires multiple times prior to the 1961 fires, yet the 1961 fire caused a substantial contraction of the A. cupressoides' range. We explain this as the combined effect of regeneration failure in burnt stands, and demographic bottle-neck in surviving stands due to severe browsing of A. cupressoides. We found that understories that develop in burnt stands were more flammable than unburnt stands due to higher fine-fuel volumes. We suggest that a warmer and drier climate will drive a feedback between regeneration failure and increased flammability causing the range of the forest type to contract to the most fire proof landscape settings. Theme: General Session Presentation Type: Oral ON THE GROWTH AND DECAY DYNAMICS OF FAST-GROWING NEOPHYTIC TREES IN SOUTHERN SWITZERLAND: NEW INSIGHTS FROM COMBINED DENDROMETER AND TOMOGRAPHY MEASUREMENTS 1,2

1

1

Jan Wunder* , Andreas Rigling , Patrick Fonti , Marco Conedera

1

1

Swiss Federal Research Institute WSL, Bellinzona/Birmensdorf, Switzerland The University of Auckland, Auckland, New Zealand

2

Neophytic tree species are currently gaining ground in the forest ecosystems of Southern Switzerland. They may accelerate their expansion in a warmer world with unknown consequences for forest ecosystem goods and services such as biodiversity, carbon storage, and protection of humans and infrastructure from natural hazards. In this project, we apply a combination of dendroecological and ecophysiological methods to elucidate the competition dynamics and physiological decay of two fast-growing neophytic tree species with different life-history strategies: the deciduous short-lived pioneer Ailanthus altissima and the evergreen latesuccessional Cinnamomum glanduliferum. We applied high-resolution dendrometers and in-situ tomography to assess the growth and decay patterns of these neophytes and their native competitors at different spatiotemporal scales, i.e. at several sites and from annual to sub-hourly resolution. Preliminary results for 2013 suggest extremely rapid diameter growth rates for the neophytic trees with peaks > 5 mm per week and 29 mm until late August (for C.glanduliferum) – despite a relatively late growth start around mid April. Moreover, first observations indicate that many large A.altissima trees are rotten inside along with an unexpected high number of C.glanduliferum trees. This suggests that the enormous growth rates of both neophytic trees may *Indicates presenting author.

130

WorldDendro2014 Accepted Abstracts come at the cost of their defences against pathogens such as wood decaying fungi. We test this hypothesis and quantify the growth and decay patterns of neophytic vs. native tree species resulting in a better understanding of the invasion potential – ultimately contributing to a more informed management of neophytic tree species in Southern Switzerland and beyond. Theme: O02. Measuring and modelling wood formation Presentation Type: Oral

X THE EXTRATROPICAL NORTHERN HEMISPHERE TEMPERATURE SINCE A.D. 850: RECONSTRUCTION OF LOWFREQUENCY VARIABILITY BASED ON TREE RINGS 1

1

1

1

1

2

Pei Xing* , Xin Chen* , Yong Luo* , Jianbin Huang* , Zongci Zhao* , Shaowu Wang* 1

Center for Earth System Science, Tsinghua University, Beijing, China Department of Atmospheric Sciences, Peking University, Beijing, China

2

We present a new reconstruction of the extratropical Northern Hemisphere (NH) mean temperature since A.D. 850 using a novel method to preserve low-frequency variability. The reconstruction is based on compilations of 31 tree ring (TR) series screened from the ITRDB and several published literatures, most of which are regional curve standardization (RCS) chronologies. Some criteria are defined in the screening procedure: series must be of annual resolution with a credible period longer than 800 years, and correlation must be over 0.30 with the extratropical NH annual land-surface temperature anomaly during 1850-2000. In order to avoid the underestimation of low-frequency variability, which has been a general problem for regression-based reconstruction methods, we utilize ensemble empirical mode decomposition (EEMD) to decompose the signals of temperature data from CRU and each TR series into four frequency components (i.e. inter-annual, decadal, multi-decadal, and centennial scale), respectively. Then estimate average series of TR network in corresponding timescales by weight of correlation coefficients, and perform the method of “variance matching” to scale the TR proxy records basing on CRU observational data. It is found that there is relatively good agreement between TR data and CRU temperature data for longer than inter-annual and decadal timescales. Therefore, low-frequency variability (longer than 30 years) of the extratropical NH temperature is reconstructed. Our result demonstrates that this method can better model the accelerating warming since 1850 and evident Little Ice Age centered around the 18th century at large scales based on pure TR data. Theme: General Session Presentation Type: Oral OXYGEN ISOTOPE SIGNATURES PRESERVED IN TREE RING CELLULOSE AS A PROXY FOR APRIL-SEPTEMBER PRECIPITATION IN FUJIAN, THE SUBTROPICAL REGION OF SOUTHEAST CHINA Chenxi Xu*, Huaizhou Zheng, Takeshi Nakatsuka, Masaki Sano 1

Graduate School of Environment Studies, Nagoya University, Nagoya, Japan Key Laboratory of Humid Subtropical Eco-geographical Process, Fuzhou, China

2

A tree ring cellulose oxygen isotope (δ18O) chronology for the period 1870-2011 was established using samples from four Fokienia hodginsii trees and one Pinus massoniana tree with the aim of exploring the potential of tree ring δ18O to reconstruct climatic variations in Fujian, subtropical region of Southeast China. We believe that this is the first tree ring δ18O chronology from this area. Response analysis revealed that tree ring δ18O is significantly correlated with precipitation between April and September, relative humidity between August and October, and the Palmer Drought Severity Index between April and October. Our δ18O chronology accounts for 39% (24%) of actual variation in precipitation between April and September during the period from 1951 to 2011(1901 to 2011). Spatial correlation analysis revealed that tree ring cellulose δ18O is a suitable proxy for reconstructing April-September precipitation in Fujian and part of Guangdong and


131

WorldDendro2014 Accepted Abstracts Jiangxi, Southeast China. In addition, significant correlations between δ18O chronology and Asian summer monsoon index shows large-scale atmosphere circulation have influences on tree ring δ18O. Comparisons between the tropical Pacific sea surface temperature (SST) and tree ring cellulose δ18O, over several time periods, indicate that the tropical Pacific SST played an important role in modulating the hydroclimate over the study region, except between 1920 and 1960, when the El Niño-Southern Oscillation (ENSO) variability was low. Theme: O01. Tropical dendrochronology Presentation Type: Oral

Y TREE GROWTH SENSITIVITY TO CLIMATIC FACTORS ALONG AN ELEVATION GRADIENT IN EASTERN QAIDAM BASIN, NORTHEASTERN TIBETAN PLATEAU 1

2

Zhi-Yong Yin* , Xuemei Shao , Yong Zhang

2

1

University of San Diego, San Diego, USA Institute of Geographical Sciences & Natural Resources Research, Beijing, China

2

Sometimes, terrain characteristics can create microclimatic conditions that influence the sensitivity of tree growth to regional climatic factors. In this study, tree ring width samples were taken from Qilian Juniper (Sabina przewalskii Kom.) at 14 elevations, ranging from approximately 3820 m to the upper tree-line at 4220 m in the eastern Qaidam Basin of the northeastern Tibetan Plateau. According to previous studies, tree growth rates at lower elevations in this region tend to be positively correlated with May-June and annual precipitation (previous July to current June) and negatively correlated with May-June temperature. Meanwhile, growth rates at the upper tree-line tend to be positively correlated with annual temperature (previous September to current August). So strengths of correlation between the ring width series and these climatic variables are used as indicators of growth-climate sensitivity to temperature and moisture condition in this study. Although the growth rates have a general tendency of decreasing sensitivity to moisture conditions as elevation increases in this area, accompanied by increasing sensitivity to temperature, the elevations where the growth rates are most sensitive to moisture condition are actually not the lowest as one would expect. We attempt to combine terrain analysis using geographic information systems (GIS) and water balance modeling to explain the variation of tree growth sensitivity to climatic factors along the elevation gradient. By doing so, we hope to develop screening criteria for future sampling sites that represent high growth-climate sensitivity to a given climatic factor. Theme: O03. Methodological challenges in dendrochronology Presentation Type: Oral FEASIBILITY OF DENDROCLIMATIC ANALYSIS OF SHRUBS IN WEST GREENLAND 1

1

1

Amanda Young* , David Watts , Alan Taylor , Eric Post

1

1

The Pennsylvania State University, University Park, PA, USA

Greenland is known as a source of long-term proxy climate data going back roughly 100,000 years. However, the spatial resolution of these chronologies is poor. New sources of proxy records need to be found in order to help clarify our understanding of ecosystems to recent climate. The use of tree-ring analysis on shrubs in the Low Arctic tundra may aid in filling in some of the gap in our knowledge. To determine the feasibility of these shrubs in a dendroclimatoloical analysis two species were sampled approximately 20 km ENE of Kangerlussuaq, Kitaa, Greenland where a climate record currently exists (1961-present). Cross-sections from 20 individuals each of Salix glauca and Betula nana were taken at each of the two to determine whether these species can be cross-dated and used for climatic reconstruction. Each cross-section was taken at ground level, roughly 2 cm above the root collar, from the largest main stem of each individual shrub (genet). Ring


132

WorldDendro2014 Accepted Abstracts boundaries of B. nana were quite faint, even after the use of phloroglucinol dye, and therefore not able to be cross-dated, while S. glauca boundaries were clearly defined and able to be cross-dated. Initial climatic analysis shows that monthly mean temperatures during the growing season are significantly correlated with ringwidth. Theme: O10. Shrub dendroecology Presentation Type: Poster AGE AND FOREST STRUCTURE ANALYSIS ALONG AN ELEVATION GRADIENT IN THE NORTHERN JAPANESE ALPS 1

2

Amanda Young* , Koichi Takahashi , Alan Taylor

1

1

The Pennsylvania State University, University Park, PA, USA Shinshu University, Matsumoto, Japan

2

The higher elevations of the Northern Japanese Alps host three major forest types (Pine Krumholtz, Birch Belt and Subalpine Forest). The existence of the Birch Belt is contrary to what would be expected at high elevation, suggesting that variability in life history traits is what allows for its persistence. Point-center quarter methods were used in 125 points between 2300-2650 meters elevation to identify and make standard measurements of individuals of Pinus pumila, Betula ermani and Abies mariesii. Structural traits across the elevation gradient show that Abies and Betula decreased in height with increasing elevation, while Pinus increased in height with elevation through the study area. Growth rates for Betula were similar across the elevation gradient, while the growth rate of the low elevation Abies was reduced compared to the higher elevation trees. Furthermore, Betula has a higher overall growth rate than Abies. Age structure analysis shows that both of these species began to establish around 1700, however, the median establishment date of Betula is in the 1950s while that of Abies is in the 1870s. Pinus began to establish in the mid-1800s and has a median establishment of the 1930s. Analyses of the trees' dispersion across the elevation transect shows that Betula is randomly distributed, while Abies and Pinus are clustered. The random distribution and young median age of Betula may account for its higher growth rate as compared to Abies. These results suggest that contrary to our initial expectations Abies displayed greater variability in growth and structural traits. Theme: General Session Presentation Type: Oral

Z AGE-DEPENDENT CLIMATE SENSITIVITY OF PICEA WILSONII MAST. IN THE XINGLONG MOUNTAIN, NORTHWESTERN CHINA 1

Fen Zhang* , XiaoHua Gou

1

1

Lanzhou University, Lanzhou, China

Temperature is widely considered as a key factor limiting the growth of treeline trees around the globe. Moisture limitation of treeline tree growth is mainly considered a regional characteristic in nature. Here we attempt to test the above two hypotheses by studying treelines in low latitude regions of the southern Tibetan plateau. The treelines under study are located at three high-elevation sites occurring within a belt between 28.5° - 30° north latitude, and 87° - 97° east longitude. The elevations of these treelines are 4670, 4680 and 4900 m, respectively. Increment core samples were collected from 20-30 individual trees at each treeline study site. The tree rings were crossdated and measured to develop a tree-ring chronology for each site. Correlation analyses showed that all the site chronologies were negatively correlated with temperature-related variables (maximum temperature, mean temperature, hours of sunshine), and wind velocity, and positively correlated with moisture-related variables (total precipitation, number of days having precipitation, relative humidity) in June and July. The same climate-growth relationships also occurred in May for the highest treeline site. We


133

WorldDendro2014 Accepted Abstracts demonstrate that the moisture limitation hypothesis from subtropical regions of South America is also applicable to low latitude treelines on the southern Tibetan plateau. This observation suggests that features unique to low latitude treelines, such as higher radiation load and lower air pressure, are contributing to moisture stress limiting tree growth. The widespread treelines on the Tibetan Plateau provide an enormous potential for further understanding of the mechanisms of treeline formation and maintenance. Theme: General Session Presentation Type: Oral GROWTH RESPONSES TO CLIMATE AT THE UPPER TREELINE IN THE ANEMAQEN MOUNTAINS – THE NORTHEASTERN TIBETAN PLATEAU 1,2,3

Hui Zhang*

1

, Xuemei Shao , Yong Zhang

1

1

Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing Linyi University College of Resources and Environment, Linyi,China 3 University of Chinese Academy of Sciences, Beijing ,China 2

Previous studies on the tree growth-climate responses in the Anemaqen Mountains of the northeastern Tibetan Plateau were mainly conducted at the elevation of approximately 3700-3845 m, and it was found that temperature in the growing season was the major limiting factor of tree growth. In this study, 120 increment cores from 60 trees of Qilian Juniper (Sabina praewalskii Kom.) collected from the upper forest timber-line ranging from approximately 4100 to 4250 m were used to investigate the tree growth-climate relationship. The results of the correlations and partial correlations between climate data and ring-width index during the instrumental period of 1956-2010 show that tree growth as measured by ring width index was significantly positively correlated with temperature from the previous December to current January and, from July to August of the current year. Meanwhile, there is a significantly negatively correlated with temperature in May of the current year. However, the response function indicates that only temperature in July of the current year produced a significant effect on tree growth. These results prove the potential of using tree ring widths at the upper forest timber-line as the proxy of past temperature variations in the study area. Theme: Z01. Other Presentation Type: Poster A NOTE ON THE DENDROCLIMATOLOGICAL VALUE OF DEAD STANDING TREES (SNAGS): A CASE STUDY FROM THE CENTRAL SCANDINAVIAN MOUNTAINS 1

1

1

1

Peng Zhang* , Hans Linderholm , Emad Farahat, Jesper Bjorklund , Mauricio Fuentes , Madelene Holmblad

1

1

Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden Botany and Microbiology Department, Helwan University, Cairo, Egypt

2

Tree-ring records have repeatedly been proved to be a reliable data source for the researches of past geomorphic events in the worldwide. However, such works have seldom been applied in China. Here a preliminary work of tree-ring dated landslide was presented. 658 samples from 327 trees (Qilian juniper, Sabina przewalskii Kom.) standing on or adjacent to a landslide body in the Qilian Mountains, northeast Tibet Plateau, China were collected to assess the growth disturbances related to landslide activity and landslide movements. The temporal and spatial characteristics of growth disturbance distribution and age structure of living trees were investigated. The results showed that the landslide may firstly happen in AD 1261, and then three major landslide years occurred at AD 1600, 1860 and 1960 separately. The 19th was the most frequent period of tree injuries since the formation of the landslide. In general, the abnormal growth of damaged trees, especially the abrupt suppression of growth, will return to normal in 5-10 years in the study area. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Poster MOISTURE LIMITATION OF TREE GROWTH AT TREELINES OF THE SOUTHERN TIBETAN PLATEAU *Indicates presenting author.

134


1

Qi-Bin Zhang* , Lixin Lv 1

Institute of Botany, Chinese Academy of Sciences, Beijing, China

Tree-ring width chronologies from 83 Piceawilsoni Mast (Wilson spruce) tree cores/48 trees taken in the XingLong Mountain were used to analyze age-dependent growth-climate response relationships. A total of 83 measurement series were categorized into two age classes : 170a (Old). Comparison of these two age classes revealed that the Old trees were more sensitive to climate influence than the Young trees except the Young trees response to the some seasonal precipitation despite the small tree age gap in this research, but some differences in response to climate between age groups are not significant. In this regard it is clear that the traditional dendrochronological sampling approach with the old trees is still the most effective way to extract the maximum climate signal from the tree ring sequences. The results of our study confirm that the older trees are more sensitive to the climate signal, but the sampling procedure non-affected by age (especially in multi-aged forests) could lead to biased mean chronologies due to higher amount of noise present in young trees compared to the old trees. This study results demonstrate that if the tree age is not accounted for when the researchers reconstructed the paleo-climate signals, the reconstruction results may be less robust especially in the multi-aged forests. Theme: General Session Presentation Type: Oral TREE-RING DATED LANDSLIDE MOVEMENTS: A CASE STUDY IN QILIAN MOUNTAINS, NORTHEAST TIBET PLATEAU 1

1

Yong Zhang* , Xuemei Shao , Eryuan Liang

2

1

Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing Institute of Tibetan Plateau Research, CAS, Beijing, PR China

2

Standing dead trees, snags, are frequently found in natural forests and may be preserved for hundreds of years. Consequently they have the potential to act as important archives of paleoclimate information to be used in climate reconstructions of the last few centuries. However, it is possible that the reason for the dying of these trees is not climatically driven, but a result of other factors, such as disease, which would make snags unsuitable as climate indicators. Here we present a study of Scots pine snags from some dendroclimatological key-areas in the central Scandinavian Mountains. Snag ring-width variability was compared to that of contemporary continuously living, healthy, trees, and using change-point analysis, growth patterns associated with the dying phases of the trees were identified. It was evident that most snags displayed significant growth depressions in the final stages their lives, which were not compatible with those of the healthy pines. Although the reasons of these growth depressions are unclear, there were no indications of those being related to sudden changes in local climate. Further, we show that including snags in chronologies created for paleoclimate purposes could possibly bias the resulting reconstructions. Theme: O07. Dendrogeomorphology Presentation Type: Oral GRIDDED HIGH-RESOLUTION PRECIPITATION RECONSTRUCTIONS OVER CHINESE MAINLAND 1

Yongxiang Zhang* , Hongbin Liu

1

1

National Climate Center, Beijing, China

Precipitation is one of the key climatic factors affecting human economies and terrestrial ecosystems. The knowledge of the variability of seasonal precipitation in past centuries at regional and continental scale is important for a society response to future climate risk. Here, we present gridded high resolution seasonal precipitation reconstructions over Chinese mainland areas (69.75-140.25E, 17.75-55.25N; given on a 2.5x2.5 resolved grid) extending maximum to past 1600 year. Point-by-point regression technique, which has been *Indicates presenting author.

135

WorldDendro2014 Accepted Abstracts successfully worked on the gridded PDSI reconstruction over North America and Asia, was employed to develop this dataset. A large variety tree-ring chronology network used for this reconstruction is composed of 330 annually-resolved records from Chinese mainland and periphery area. These chronologies cover the past 100 to 2,000 years, with a median age around 400 years, and all end on or after AD 1993. Addition to tree ring data, precipitation indices based on documentary evidence and other proxies (ice cores, corals and a speleothem) were used for helping this reconstruction. Preliminary results show that this precipitation dataset could capture the general spatial precipitation pattern and major precipitation variations during reconstructed period over Chinese mainland. With further improvement this dataset will provide a comprehensive background for understanding the regional long-term changes in precipitation and drought patterns and their links to controlling circulation influences. Theme: O04. Large-scale climate reconstructions and models Presentation Type: Oral CLIMATIC INFORMATION RECORDED FROM TREE-RING δ13C ANNUAL SERIES IN THE EASTERN SUBTROPICAL REGION OF CHINA 1,2

3

4

4

3

3

Xingyun Zhao* , Ziwei Zheng , Zhiyuan Shang , Jian Wang , Ruiqin Cheng , Chengwen Xu , Junlong Qian

5

1

Institute of Resources and Environment, Linyi University, Linyi 276000, China Shandong Provincial Key Laboratory of Water and Soil Conservation & Environmenta 3 College of Population, Resources and Environment, Shandong Normal University, J 4 College of Geographical Science, Nanjing Normal University, Nanjing 210046, China 2

We developed three annual-resolution Cryptomeria fortunei tree-ring δ13Cp chronologies, which collected from west Tianmu Mountain (30°20’²N, 119°26’²E), belongs to the eastern subtropical area of China, were determined based on cross-dated tree-ring age. As expected, there was a significant decline in three tree-ring δ13Cp chronologies occurred from 1685 to 1985 in response to increasing atmospheric CO2 concentrations and decreasing atmospheric δ13Ca. The high frequency correlation analysis between the three tree ring δ13Cp series and meteorological parameters revealed that the maximum temperature in autumn and winter most strongly influenced tree ring δ13Cp discrimination from 1956 to 1996. To reduce the noise and enhance the climatic signals, we respectively compared three previously published correction method to remove the lowfrequency variation in tree ring δ13Cp chronology. We found that the most suited correction method was the δ13Ccor correction method in our study area and got a discrimination rate of about 0.0213%/ppmv-1 for the CO2 partial pressure , correspondingly the strongest influence factor was the current October-December maximum temperature. Mainly the varied history of current October-December maximum temperature was reconstructed from 1685 to 1985. The results show a slight warming trend and also have a better correspondence with some climate events recorded in historical records. Therefore, our results provide a potentiality for reconstruction of the autumn and winter temperature on a centennial scale in the eastern subtropical region of China. Theme: O06. Stable isotopes in dendrochronology Presentation Type: Oral COMPRESSION WOOD FORMATION AS AN INDICATOR OF THE PAST WINDTHROWS IN A MOUNTAIN SPRUCE FOREST 1

2

2

Tomasz Zielonka* , Jan Holeksa , Magdalena Ûywiec , Natalia Dubaj

2

1

Institute of Biology, Pedagogical University of Cracow, Krakow, Poland Institute of Botany, Polish Academy of Sciences, Krakow.Poland

2

Windthrows aside from bark beetle infestations are the most serious disturbances which affect spruce stands in Europe. Spruce forests are especially vulnerable to wind damages in the mountain regions. Wind storm events are unpredictable thus the knowledge of the local history of this kind of disturbance, its interval and severity is very important to understand and estimate the potential hazard nowadays and in the future. In this paper we present the results of a tree-ring reconstruction of the past windthrows in the Carpathian *Indicates presenting author.

136

WorldDendro2014 Accepted Abstracts Mountains. As the development of compression wood is often related to wind influence on tree stem, we used this indicator for wind storms detection. For this purpose 700 spruce cross-sections were inspected to identify the presence of compression wood in stems. The tree-rings when compression wood was produced were cross-dated. Our results show that formation of compression wood was escalated in some periods during the last 200 years, and the abrupt initiation of compression wood formation was synchronized among trees. Disturbance signal based on compression wood was also well synchronized with the other indicators of disturbance events like releases, occurrence of resin pockets and historical data. What more, an abrupt initiation of compression wood formation enabled the detection of past windstorm of lower severity, which could not be determined with the other dendrochronological methods e.g. releases. We conclude that compression wood might be a very valuable and sensitive indicator of the past disturbances, especially these of lower intensity. Theme: O05. Identifying discrete events in the tree-ring record Presentation Type: Oral RECRUITMENT DYNAMICS OF THE WOLLEMI PINE: COMPARING DEMOGRAPHIC AND DENDROECOLOGICAL DATA 1

2

3

1

Heidi Zimmer* , Rohan Simkin , Tony Auld , Patrck Baker 1

University of Melbourne, Melbourne, Australia Biosis, Melbourne, Australia 3 Office of Environment and Heritage NSW, Sydney, Australia 2

Wollemi pine (Wollemia nobilis; Araucariaceae) is a rare endemic Australian conifer and a conservation icon due to its recent discovery within 200 km of one of Australia’s most populous cities. The wild population consists of 85 mature individuals and 200-300 seedlings and juveniles. Wollemia juveniles grow very slowly, with height growth typically