Accepted Manuscript Beech forests of Azerbaijan: the modern condition, age structure and regeneration Z.M. Hasanov, Z.A. Ibrahimov, V.R. Nabiyev PII:
S1512-1887(16)30054-9
DOI:
10.1016/j.aasci.2016.08.003
Reference:
AASCI 36
To appear in:
Annals of Agrarian Sciences
Received Date: 19 November 2015 Accepted Date: 17 July 2016
Please cite this article as: Z.M. Hasanov, Z.A. Ibrahimov, V.R. Nabiyev, Beech forests of Azerbaijan: the modern condition, age structure and regeneration, Annals of Agrarian Sciences (2016), doi: 10.1016/ j.aasci.2016.08.003. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Annals of Agrarian Science vol. 14, no. 3, 2016
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Beech forests of Azerbaijan: the modern condition, age structure and regeneration Z.M.Hasanov, Z.A.Ibrahimov, V.R.Nabiyev
Corresponding author: Z.M. Hasanoz
[email protected]
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Abstract
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Azerbaijan State Agricultural University 262, Ataturk's avenue, Ganga, Az2000, Azerbaijan Republic Received 19 November 2015; Accepted 17 July 2016
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Azerbaijan is a country with low forest cover, only 11.8% of the territory is covered with forests. All forests perform important water-soil-protection functions. In forests, naturally grow 107species of trees and 328 shrubs species. Despite the fact that there are many species in dendroflora, only 10 tree species have economic value for the forest sector of the country. Beech (31.68%), oak (27.40%) and hornbeam (26.01%) are growing in 85.09% of forested areas. Beech forests are spread on 327 thousand hectares from 989,5 of total forest lands of he Republic. Beech forests are a source of high-quality wood and beech nuts. All beech forests grow in mountains at heights of 600-800 and 1600-1800 m above the sea level and performing important ecological functions. Until recently there were no problems with natural renewal of the beech forests, but now the regeneration of beech forests is alarming. In recent years, the productivity and density of beech forests decreased substantially, the natural regeneration proceeds unsatisfactorily and, consequently, reduction of beech forests takes place. We have researched 33,8 thousand hectares of beech forests of the Lesser Caucasus, their natural regeneration and made analysis of age structure of forests. Keywords: Fagus orientalis, Beech forests, Silviculture, Natural regeneration, Age class
1. Introduction
National development strategy of forests of Azerbaijan provides for increase of the forest area by creation of silviculture and activities for natural regeneration of valuable (main) tree species. Annually in Azerbaijan produced silviculture on the area of 2.5-3.0 thousand hectares and promotion for natural regeneration on 7.0-7.5 thousand hectares. Every year 10 thousand hectares of
young forest stands are transferred into wooded area. Among transferred forest lands the natural young plants 2.5-3.0 time exceeds the forest plantations produced artificially [2,3]. The natural regeneration requires less works, material, and financial resources. Secondly, natural regeneration is more productive and resistant to external
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growing conditions and elimination of negative impact of external factors [6-8].
In Azerbaijan the beech forests are spread on 327 thousand hectares from 989.5 thousand hectares of total forest lands. Beech forests occupy 32% of the total forest area of the Republic [9,10]. Beech forests are the source of high quality wood, beech nuts as a raw and processed form are used as a food sources,it is also used as a raw material to produce highquality vegetable oil and different technical purposes. Growing up in the mountains, they
particular class - their spatial distribution. The sustainable forest management is the desire of foresters to reach balanced distribution of stands by age classes. A balanced distribution of stands by age classes can be achieved by regulation of natural regeneration. Done the analysis of age structure, examination and evaluation of natural regeneration of beech forests of the Lesser Caucasus. For this purpose, was used information concerning forest inventory and forest fund registration from five forestry enterprises in the Western part of Azerbaijan with the total area of forests 84.800 ha, including 33.800 ha of beech forests. Considered beech forests were presented in 9 age classes (I-IX, with the duration of each age class 20 years). Analysis of age structure of forests carried out by using class methods of forest management (15), for the estimation of natural regeneration was used the scale of Nesterov [16. When assessing the quality and quantity of natural regeneration were taken into consideration such points as soil type, grass cover, slope, aspect and height above sea level. Registration and evaluation of natural regeneration of Oriental beech were carried out on plot areas. Plots with size 0.25; 0.5 and 1.0 hectares are covering at least 10% forest stands. On each plot in the diagonal direction created 25 small additional plots. Depending on the age of natural renewal the size of every small plots are the following: under 5 years of natural renewal 1-2 m 2 , at
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environmental factors. Compared to artificial forests, natural forests are easier to manage and easier to predict the dynamics of their development [4,5]. For a successful natural regeneration it is necessary the optimal 2. Objectives and methods
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perform important ecological functions [11,12]. Increasing anthropogenic impact, changing environmental conditions adversely affect the natural regeneration of beech forests. The absence or insufficient natural regeneration contributes to replacement of beech forests by secondary forest species such as hornbeam, maple and so on, and as a result such changed beech plantations are transformed to thickets, or to forest less areas. This ultimately leads to reduction the area of beech forests, and can not disturb the foresters and researchers. The goal of this research was to study methods of sustainable beech forests management of Azerbaijan Republic. The sustainable forest management firstly puts forward the need for spatial-temporal analysis of the distribution of plants. The spatial analysis involves the areas of forest stands, and the temporary analysis of the age of trees in the specific area. The answer to this question can be obtained according to the analysis of the age structure of the plantations. Distribution of stands by age classes reflects their spatial-temporal distribution. The age specific class reflects a temporary, and the area of plantations in a
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the age of 5-10 years 5-10 m 2 , more than
10 years 0,1-0,2 ha.
3. Results and analysis
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seedings on a hectare. However, most of them die the first year. In the first years of life in the undergrowth, there is an intensive differentiation of the young generation of the forest that leads to a natural eradication. In order the foresters be able to justify the choices of a natural or artificial way for the resumption of beech forests firstly requires an assessment of the status of natural regeneration. Given that beech forests of the region are of seed origin, the duration of the age classes adopted in 20 years. Specific age class combines plantings with the difference in age between 20 years and these forest stands with economic and reproductive terms represent the same value. Reproductive maturity of beech forest stands occur after V age class, and such forest lands (VI - IX classes of age) are 37.6% of the total surveyed beech plantations area (table 2). Only 40 % reproductive ripe beech plantations of theRepublic had been observed enough natural regeneration. Analysis of the age structure and evaluation of natural regeneration allows us to predict the future and to identify ways of sustainable management of beech forests. Beech forests of the Lesser Caucasus in the western regions of theRepublic on the area of 33,8 thousand hectares unevenly distributed in 9 age classes (I-IX) (table 2). Age classes I, II, III and VII, VIII, IX represent less than 10% of beech forests (8.5 and 10%, respectively). The area of the first (I) and the ninth (IX) age class is less than 1% of the total area of beech forests. Middle-aged beech forests merges IV, V and VI classes of age and being dominant occupied about 81.5% of the total area (33.8 thousand hectares) of beech forests. The absence of young stands is the result of insufficient regeneration of beech forests by natural regeneration. Up to 70-80 years of the XX century in the beech forests was conducted forest regeneration cuttings.
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The progress of natural regeneration of forest depend on many factors and requires certain conditions, such as: • The first necessary condition for the success of natural regeneration of forest is the onset of reproductive maturity of the stand. Reproductive maturity occurs at the age at which a plantation begin to give abundant harvest of seeds. Reproductive maturity is the synonymous with renewal ripeness. • The success of natural regeneration determines the sufficiency of the forests with high quality seeds. Seeds are the initial reproductive material. A young generation of the forest is growing from seeds. Provision forest lands by seeds is one of the important conditions for natural regeneration of forests [17]; • Forests can produce high seed yield, but the biotic, abiotic and anthropogenic factors able to make the seed crop is insufficient for the resumption of the forest. • The next step in determining the success of natural regeneration is the condition of seed germination. Fallen from trees, the seeds need to get in a good soil condition suitable for germination, after which seeds give rise to a new generation of forest. Falling on a thick layer of forest litter or grass cover, their root system does not reach the soil and tend to dry out and die. Fallen from trees, the seeds must reach the soil surface in winter being under the layer of leaves and snow, swell from the melting snow and rain waters and in spring germinate after occurrence of an optimal temperature regime. The next determining factor is the availability of conditions for the growth and development of self-sowings and undergrowth. After an abundant harvest of seeds under the canopy of trees formed many thousands and even millions of self-
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age classes could be represented by the formula:
Sn =
∑S n
where: Sn - forested area of a specific age class, ha;
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ΣS is the total wooded area (area of all age classes), ha; p is the number of age classes (e.g. I, II, III, .... VIII, IX, n = 9).
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The studied beech forests are critically distinguished by unequal distribution by age classes. Forested area within each age class ranges from 203 to 12333 ha (table 2, age class I and V.). Sustainable management of beech forests in the region should be aimed at even distribution across the age classes. In accordance with this, each age class must take 3500-4000 hectares (33803: 9 ≈ 3750). Given that the duration of the age classes 20 years, and each of the age classes should be represented on the 3500-4000 hectares, annually in the 175 - 200 ha required the carrying out of reforestation works through the promotion of natural regeneration or the establishment of artificial forests.
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These cuttings not only provided a natural beech forest renewal, but also exhausted mature stands. Therefore, ripe beech forest stands now are only 10% from total beech forests. The greatest concern is the weak presence of young-growth stands (8,5%) in the structure of beech forests (age classes IIII), indicating the absence of natural regeneration over the last 50-60 years(table 3). The lack of resumption indicates a sharp reduction the area of beech forests in the future. Elimination of factors negatively influencing the process of natural regeneration and the implementation of the activities to promote natural regeneration is the primary task in the beech forests of the region. Analysis of the age structure in the Western region of Azerbaijan showed that the distribution of beech forests by age classes is subject to the law of normal distribution (Fig 1-4). The only difference is that in the distribution area of beech forests by age classes left or the right branch of the distribution curve to some extent is compressed or stretched. Excluding the offset to the left or right of the distribution curves of beech forests, distribution closely approach to the normal distribution curve. ("Bellcurve”).
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Sustainable management of beech forests comes from a uniform distribution of stands by age classes. A hypothetical mathematical model of a uniform distribution of stands by 4. Conclusion
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Analysis of the age structure 33803 hectares of the beech forests in the lesser Caucasus showed that in composition of beech forests are dominated middle-aged forest stands (81,5%). The young (8.5%) and ripe (10,0%) forest stands are represented weakly. The low percentage of young stands indicates the insufficient seed availability in beech forests. Ripe beech forests (10 %) are only 40 % of the territory and are provided with
natural renewal. Uniform distribution of stands by age classes are determining factor for sustainable forest management. Based on this principle in each age class (I-IX) of beech forests should be submitted 3.0-4.0 thousand ha forests. Balanced equal distribution by age classes requires the annual forest restoration activities on 175 to 200 hectares.
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REFERENCES
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[1] http:// www. eco.gov.az [2] F.A. Amirov. Forests and Forestry Republic of Azerbaijan, Publishing House “Elm”, Baku, 1997, pp 92 (in Azeri). [3] Q.S. Mammadov, M.Y. Khalilov. Azerbaijan's Forests, Publishing House "Elm", Baku, 2002, pp. 472 (in Azeri). [4] P. Pejman, T. Khosro Sagheb, M. Asadollah, R. Nyland, M. Namiranian. Silvicultural Characteristics of Oriental beech (Fagus orientalis Lipsky.) Regeneration under Different RLI and Positions Within Gaps. 2011, pp. 177-185. [5] K.N. Zaytsev. Oriental Beech Regeneration after the Cutting, Forest farming Information’s J., 8 (1994) pp. 28-35 (in Russian). [6] Z.A. Ibrahimov, V.R. Nabiyev. The Natural Regeneration of Oriental Beech (Fagus orientalis Lipsky.) Forests in Hajikend area. 2014, pp. 305-306 (in Azeri). [7] B. Ö. Halil, K. Erol, K.K. Rabia. Determination of the Factors Affecting the Success of Natural Regeneration in Oriental Beech (Fagus orientalis Lipsky) Forests (Devrek-Pürenkaya Case Study), 2015, pp. 14. [8] S.E. Side, P. Hassan, P. David, O. Ali, T. Javad. Effect of Livestock Grazing and Human uses on Herbaceous Species Diversity in Oriental Beech (Fagus orientalis Lipsky) Forests, Guilan, Masal, Northern Iran, J. of Forestry Science. Volume 25, Issue 2 (2014) pp. 455-462. [9] V.R. Nabiyev. Ensuring the Restoration of Oriental Beech Forests (Recommends), 2015, pp. 28 (in Azeri). [10] Ibrahimov Z.A., Nabiev V.R. Beech forests of Azerbaijan: the Modern Condition, Age, Structure and Renewal, 2015. pp. 64 (in Azeri). [11] G.S. Vachnadze, G.V. Tsereteli, Z.T. Tiginashvili, B.H. Aptsiauri, E.E. Nakaidze. Evaluation of Organic Carbon Stock in Soils of Beech Forests of Eastern Georgia, Annals of Agrarian Science, Vol. 13 No 2 (2015) pp. 81-88. [12] A.P. Poqorelov, S.Y. Shevela. Geomorphological Conditionality Taxations Indicators of Oriental Beech in the Conditions of a Mountain Relief (on an Example of the Caucasian Reserve), Scientific J. of KubSAU, № 93 (09) (2013) pp. 18-31 (in Russian). [13] S.T. Khosro, S. Jean‐Philippe. The Structure of Natural Oriental Beech (Fagus orientalis Lipsky) Forests in the Caspian Region of Iran and Potential for the Application of the Group Selection system, Forestry, 75 (4) (2002) pp. 465-472. [14] S. Kiomars, R. Mohammad, M. Marvie, M. Reinhard, A. Carolyn, H. Copen. Canopy gaps and Regeneration in Old-growth Oriental Beech (Fagus orientalisLipsky) Stands, Northern Iran, Forest Ecology and Management (USA), Volume 262, Issue 6 (2011) pp.1094–1099. [15]. N.P. Anuchin. Forest Inventory (Textbook), Publishing House “Ecologia”, Moscow, 1991, pp. 400 (in Russian). [16]. V.Q. Nesterov. Forestry. Publishing House “Qoslesbumizdat”, (1954) pp. 273-276 (in Russian). [17] B. Halil, A. Sezgin, K. Erol, K. Rabia. Effects of Climate Change on Seed Production in Seed Stands of Oriental Beech (Fagus orientalis Lipsky) in the Bartin region in Turkey, 2015, pp. 15.
Acknowledgements Authors, dr., prof. Z.Hasanov&dr., prof. Z.Ibrahimov would like to express gratitude to the Science Development Foundation under the President of the Republic of Azerbaijan for financing this research withingrant № EİF/MQM/Universitet-2014-5(20)-11/05/3-M-01).
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Table 1.Oriental beech forests in Lesser Caucasus Including beech forests hectares % 6953 34,6 12133 67,3 5901 26,2 688 20,9 8128 39,0 33803 39,8
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Dashkesan Kedabek Goygol (Goranboy&Shamkir) Qazax Tauz Total
Total forest area, hectares 20089 18040 22551 3294 20853 84827
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Forest Management Unit
Table 2.Age classes and age stages of oriental beech forests, Lesser Caucasus
Dashkesan
I
II
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73 0,6 24 0,4 -
620 5,1 Goygol 77 1,3 (Goranboy&Shamkir) 18 Qazax 2,6 106 389 Tauz 1,3 4,8 203 1104 Total 0,6 3,3 Young age stages (8,5%)
17 0,2 752 6,2 531 9,0 45 6,5 211 2,6 1556 4,6
728 10,6 1820 15,0 1540 26,1 163 23,7 1634 20,1 5885 17,4
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Kedabek
Beech forest area stages of age classes, ha /% III IV V VI VII VIII IX
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3562 1288 51,2 18,5 3554 4065 29,3 33,5 1835 1322 31,1 22,4 244 136 35,5 19,8 3138 2528 38,6 31,1 12333 9339 36,5 27,6 Middle age (81,5)
633 480 245 9,1 6,9 3,5 1225 12 12 10,1 0,1 0,1 489 77 6 8,3 1,3 0,1 56 17 9 8,1 2,5 1,3 106 8 8 1,3 0,1 0,1 2509 594 280 7,4 1,8 0,8 Mature and old (10,0%)
Total 6953 100 12133 100 5901 100 688 100 8128 100 33803 100
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Table 3.Degree of natural recovery of beech forests
Indicator
Forest covered area by age stages , ha/% Degree of natural regeneration *
Young 2863 8.5 *
Age stages Middle age Mature and oldest 27557 3383 81.5 10.0 0,1-0,3 0,6-0,7
Total 33803 100 -
The young trees themselves are squeezed as a result of natural recovery or a natural recovery
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Forest covered area, %
60
Dashkesan Forest Farming
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51.2 50
30
20
10.6
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18.5
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6
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3.6 10
Age classes 12
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Fig.1.Distribution of age classes in beech forests, Dashkesan Forest Management Unit
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Forest covered area, %
40
Kedabek Forest Farming 33.5
35 29.3
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30 25 20 15 15
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10.1
10 6.2
5.1
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5 0.6 0 0
2
4
6
0.1
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8
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Fig.2.Distribution of beech forests on age classes. Gedabek Forest Farming
Age classes 10
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35
Forest covered area, %
Goygol Forest Farming 31.1
30 26.1 25
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22.4 20 15 10
9
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8.3 5 1.3 0 0
2
4
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1.3
0.4
6
0.1
8
10
Age classes 12
Fig.3.Distribution of beech forests on age classes. Goygol Forest Farming
Qazax Forest Farming
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40 Forest covered area, %
35.5
35 30 25
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23.7
20
10 5 0
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15
19.8
8.1
6.5
2.6
2.5
1.3
0
0
2
4
6
8
10
Age classes 12
Fig.4.Distribution of beech forests on age classes. Qazax Forest Farming
