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understanding of ecosystem ecology and engineering design to create functional ecosystems that provide services to both human society and the natural environment”, explains Nairn. “If the passive treatment system provides long-term, low-maintenance solutions to water contamination caused by historical [mining] activities, degraded streams will have an opportunity to recover chemically and biologically.” So far the system has been tested at two sites in the US, both in Oklahoma, and in Potosi, Bolivia. Each environment presents challenges

to implementation, including radical differences in landscape geography. “Designs are site- and source-water specific, so process unit selection, sizing, and configurations will vary depending on site characteristics”, says Nairn. Designs can be adjusted for geographic, climatological, ecological, and other conditions.” Improvements in water quality – such as decreased metal concentrations and stabilized pH and alkalinity levels – have already been documented, but the project still faces hurdles. According to Nairn, “contaminant retention in passive treatment systems raises concerns about the potential for bioaccumulation”. While the system is designed to mitigate such complications, comprehensive monitoring programs are necessary to ensure success. Although the passive water-treatment system uses natural ecological processes, the method is still a bit of a “black box”. Nairn’s team seeks to understand and optimize the specific mechanisms at work and to evaluate “ecosystem services beyond waterquality improvements – such as carbon footprint analysis, habitat provision, and water supply – as well as environmental education efforts”. n

emerald ash borer (Agrilus planipennis), an invasive species responsible for the loss of 100 million trees across 15 US states between 2002 and 2012. Donovan noticed increased human mortality – 15 080 deaths from cardiovascular disease and 6113 deaths from respiratory illness – following the pest outbreak; the magnitude of the effect was greater during the later stages of the infestation. The most plausible explanations for this relationship could be decreased physical activity, reduced air quality, or increased stress. Interestingly, the connection between tree infestation and human mortality was higher in wealthier counties. It’s unclear why, but wealthier areas possibly have more tree cover to begin with and therefore would be more adversely affected by tree loss. “This research looks at a natural experiment that occurred somewhat randomly over a broad geographic

area, offering yet another interesting way to push forward our understanding of whether environmental factors offer health benefits”, comments Gina Lovasi, an epidemiologist at Columbia University (New York, NY), whose own research detected decreased prevalence of asthma in children living in urban areas with more street trees (J Epidemiol Commun H 2008; doi:10.1136/jech.2007.071894). However, she cautions, ecological analyses such as this aren’t always confirmed by more rigorous, follow-on studies at an individual level. “These studies are important because they give us an idea of what direction to take future research.” Donovan agrees. “We need to quantify the benefits, to help local governments make appropriate decisions when allocating money”, he says, adding “if we can’t count a thing, it doesn’t count.” n

Ecological solutions to mine water pollution Lindsay Deel In the deserts of southern Bolivia, much of the region’s limited water resources is tainted by pollution from nearby mining operations. However, a new passive water-treatment method developed by engineers from the University of Oklahoma may hold the key to improving the area’s water quality in an ecologically responsible way. “In Bolivia, water is crucially important to agriculture. When irrigation waters are left untreated, the human health risk from consumption of staple root crops is unacceptable”, says Robert Nairn (Director of the Center for Restoration of Ecosystems and Watersheds, Norman, OK). This novel water-treatment system funnels untreated water through a series of filtration ponds, where natural biological or chemical processes remove pollutants from the water as it flows back toward natural waterways. “The general idea is to marry our

Tree loss tied to human deaths? Virginia Gewin New research has found a connection between trees and human cardiovascular–respiratory health, thus adding a bit of statistical heft to a growing body of evidence that the natural environment can have public health benefits and providing stronger support for a causal link. Previous studies identifying such an association have typically relied on single time-point observational studies, which are often unable to rule out confounding factors. US Forest Service economist Geoffrey Donovan (Portland, OR) used county-level health records from 1990–2007 to track the impacts of a massive tree kill event that began in 2002 (Am J Prev Med 2013; doi: 10.1016/j.amepre.2012.09.066). The trees died after an outbreak of the www.frontiersinecology.org

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Mayer Ranch passive treatment system at Tar Creek Superfund site, OK (February 2009).

© The Ecological Society of America

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Spotlight on global mercury pollution Noreen Parks In mid-January, after years of debate, delegates from 140 countries agreed to a legally binding treaty to reduce releases of mercury (Hg) from various products and industries, ranging from medical equipment to mining, cement production, and coal-fired power plants. Even as talks were underway, recent findings emphasized the need for global action to curb one of the planet’s most serious threats to human and environmental health. A UN Environment Programme (UNEP) report released in January revealed that after declining from 10 000 metric tons (mt) to 1000 mt between 1971 and 2001, Hg mining output doubled over the past decade, largely due to the rising use of Hg in small-scale gold mining, energy-efficient lighting, and vinyl chloride plastics. At the same time, Hg emissions fell in some geo-

graphic areas, and overall emissions from 1990 to 2010 – estimated at 1960 mt – were roughly stable. Developing nations now account for more than 80% of those emissions. Wind-transported Hg can circulate vast distances before falling to Earth, where microbial activity converts it to toxic methylmercury, the form taken up by animals. During the 20th century, the total Hg deposited in the planet’s oceans and freshwater doubled, according to UNEP. Furthermore, climate-change impacts are boosting the availability of Hg trapped for millennia in ice and snow. A study found that river flows amplified by warming-induced melting contributed most of the Hg detected in the Arctic Ocean (Nat Geosci 2012; doi:10.1038/ ngeo1478). In addition, thawing permafrost and increasingly frequent forest fires are intensifying concentrations of Hg in high-latitude soils. New research suggests that reducing Hg emissions could have immediate environmental benefits (Sci

Total Env 2012; doi:10.1016/j.scitotenv.2012.10.069). When scientists in Ontario, Canada, added a particular Hg isotope to lake waters, lake perch showed surprisingly higher concentrations of it within months, compared to “older” Hg already present in the lake. Within a year, the “new” Hg had passed up the food chain to top predators. When Hg additions ceased, Hg levels in the fish dropped quickly. Many parts of the new treaty won’t take effect until 2020 or later, and large-scale positive consequences could be decades away. David Lennett (Natural Resources Defense Council, Washington, DC) contends that “the provisions on product phase-outs are relatively strong, while the emissions control requirements for existing facilities are delayed far too long”. Still, he adds, “the agreement is a good starting point for building international cooperation, and there’s room for improvements down the line”. n

A baby gorilla watches its mother and other family members forage for food.

Government to protect the area after the gorillas were discovered there by WCS researchers in 2008. Because of the relative political stability in the Republic of Congo – unlike that in the neighboring Democratic Republic of Congo, where civil war continues to complicate conservation efforts – Deutsch believes this park will thrive. “No doubt there will be threats, including poaching for elephants and other valuable wildlife, but we believe that by working with the government, communities, and other partners, we can meet these challenges.” As for how the Congolese people might benefit from the new park, Deutsch points out, “The area itself is uninhabited, and we have worked with local communities to ‘grandfather’ their fishing rights in the river that forms one boundary of the park. We hope over time to be able to monetize the averted deforestation that has resulted from the park’s creation and to use the proceeds to benefit local communities.” n

T Breuer/WCS-Max Planck Inst for Evolutionary Anthropology

Republic of Congo protects gorillas’ “green abyss” Jen Fela The Wildlife Conservation Society (WCS) announced in late January that the Republic of Congo has declared a new national park that protects 4572 km2 of land, including a remote swamp dubbed the “green abyss” by the first WCS researcher to explore the area. The NtokouPikounda National Park counts among its residents 8000 forest elephants, 950 chimpanzees, and a substantial hippopotamus population. With the addition of this new park, protected areas of the Republic of Congo now account for more than 11% of the country’s land. James Deutsch, WCS Executive Director for Africa Programs (New York, NY), says the park is “extraordinary – it is highly inaccessible because of dense Marantaceae vegetation and seasonally flooded forests, and this inaccessibility has enabled the fauna and flora to remain unusually intact.” © The Ecological Society of America

But the park’s foremost distinction is that it is home to an estimated 15 000 western lowland gorillas, a critically endangered species with fewer than 200 000 remaining in the wild. Gorillas across central Africa are threatened by hunting for bushmeat, habitat destruction caused by deforestation, and the spread of the deadly Ebola virus. Creation of the NtokouPikounda National Park fulfills a promise made by the Congolese

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Wyoming wind balances California renewables Robin Meadows Wyoming has wind power when California needs it, making this renewable energy source potentially more reliable and cheaper for Californians, according to a new report. “Wyoming wind rips in the winter”, says Loyd Drain, Executive Director of the Wyoming Infrastructure Authority (Cheyenne, WY), which facilitates consumption of the state’s electricity. In contrast, California’s winds are weakest during the winter. In addition to being strong – often blowing at speeds of 10–12 m s–1 – Wyoming wind is steady. “It’s amazingly consistent here”, observes Jonathan Naughton (University of Wyoming, Laramie), lead author of the January 2013 report Wind Diversity Enhancement of Wyoming/California Wind Energy Projects. Naughton’s team projected wind power in Wyoming and California based on atmospheric data, and found that it is complementary year-round. Besides balancing each other in the winter, wind power in the two states has opposite daily pat-

Burning target a threat to rare species Claire Miller Endangered species in the Australian State of Victoria are at risk from a government commitment to burn at least 5% of the state’s public land annually, in an effort to reduce fuel loads. The 5% target – 380 000 ha per year – was recommended by a Royal Commission investigating the deadly wildfires in February 2009, in which 173 people died. But scientists warn that such a blanket approach will lead to converse outcomes, with agencies burning vast remote regions rather than strategically important areas closer to towns. “If the rationale is to reduce the risk to life and property, then obviously you [take action]

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Wyoming’s wide open spaces make it ideal for wind ranches.

terns during the summer, peaking at noon and then dropping in Wyoming while the reverse occurs in California. Wyoming wind likewise complements California’s solar power. “Solar goes to zero when the Sun goes down, and our wind could fill half that energy gap”, explains Drain. At present, renewable energy gaps are commonly filled with energy produced from fossil-fuel-burning power plants. Importing Wyoming wind power would also lower energy costs for Californians. Rates are already four to eight times higher in California than in Wyoming, and are predicted to rise further as California tries to meet its mandate of producing one-third of its energy from renewables by 2020. Buying Wyoming wind power would where life and property are at risk”, explains Mike Clarke (La Trobe University, Melbourne, Australia). “If you keep burning remote parts of Victoria, you’re not making anyone safer, and you have the potential to do ecological harm.” The semi-arid Mallee country of Victoria’s far northwest is a case in point. Some tracts in the Mallee have not burned for up to 140 years, allowing complex habitat structures to form – structures that would otherwise be lost, according to Clarke and his colleague Andrew Bennett of Deakin University (Melbourne). For example, the endangered Malleefowl (Leipoa ocellata) relies on ground litter that has accumulated over decades to rake into their large nest mounds, tree hollows take at least 40 years to form, and spinifex grass (Triodia spp) requires a

save California ratepayers $600 million per year, according to a 2011 study by the Western Electricity Coordinating Council (Salt Lake City, UT). Because the power grid that currently serves the western US is at capacity, sending wind-produced electricity from Wyoming to California would require the construction of a new high-voltage transmission line. The TransWest Express, a 1167-km line linking Wyoming to southern Nevada, is being planned; connecting that line to California’s grid would be relatively easy, and it could be up and running by 2017. To actually build the Nevada–California extension would, however, require power purchasing agreements from public utilities in California. Drain is now in talks with energy officials there, but so far there are no takers. Adding even more long-distance transmission lines would facilitate moving electricity as needed throughout the western US. “Right now, each state maximizes its own resources, but we should maximize resources regionwide”, Naughton recommends. “This is the way to make renewables really work.” n minimum of 20–30 years to reach maturity. “So the concern is that if you burn 5% every year, logically after 20 years you’ve burned an area equivalent to 100% of the region. How do you then provide extensive areas of Mallee habitat that is 30, 40, or 80 years old?”, asks Bennett. “If you burn large areas repeatedly at intervals of less than 20 years, to allow other areas to develop older vegetation, it will put plant communities at risk.” The scientists are calling for the 5% target to be replaced with a risk management objective. “We’re not opposed to planned burning per se, and absolutely we need to protect human life and property, but our argument is that targets should be based on reducing risk”, says n Bennett.

© The Ecological Society of America


Alison Gillespie Because bat guano makes a rich fertilizer that is prized by farmers, quiet caves with unique and fragile ecosystems often become targets for those willing to wield shovels in the pursuit of quick cash. Biologists have observed that the bright lights and loud equipment used in guano excavation can cause residing bats to drop their pups or even abandon the cave altogether. Now, a team of conservation biologists has drafted a set of working guidelines that they hope could eventually be used to improve the sustainability of guano mining in many locations by reducing its negative impacts. Officials estimate that millions of bats have been lost worldwide as a result of guano mining, although accurate data are lacking. “We’re receiving many reports of declines in cave bat populations”, says Nina Ingle (Davao City, Philippines), who has worked as a bat biologist for 20 years. “There’s an urgent need for

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New guano mining guidelines drafted

Guardhouse at the entrance to a Cambodian bat cave.

further research on their status as well as for cost-effective methods to monitor bats and the impacts of guano harvesting.” That need was also recognized by several environmental organizations, which collaborated to sponsor the Emerging Wildlife Conservation Leaders Bat Group (EWCLBG), a team that was formed to examine guano mining issues. Some members of the EWCLBG accompanied Cambodian researchers in the field as they tested methods for improving sustainability during the guano harvest at several locations last year, and

Adrian Burton Researchers report that African dung beetles (Scarabaeus satyrus) use the Milky Way to help them speedily steer their hard-won manure balls out of competitors’ reach (Curr Biol 2013; doi:10.1016/j.cub.2012.12.034). This is the first evidence of such a navigation system being used by any animal. Dung beetles eat – and lay their eggs in – other animals’ droppings, and competition around the nighttime manure pile can be fierce. “Rolling a ball in a straight path away from the pile makes for the shortest journey time to a safe mating area”, explains Eric Warrant (Lund University, Lund, Sweden). “During the day, these animals orient themselves by using cues like the Sun, and at night we know they can use the Moon. But they can also roll © The Ecological Society of America

M Byrne

Dung beetles navigate by the galaxy

Starstruck beetles navigate using the Milky Way.

a ball straight when there is no visible Moon; so we asked whether they were using the starry sky.” On a star-filled, moonless South African night, the researchers placed beetles with dung balls in a circular arena, and measured the tracks they followed as they tried to steer their prizes to the arena’s edge 120 cm away. Those prevented from seeing the heavens by a cardboard cap placed over their dorsal eyes made tracks twice as long as those wearing no caps

in January a working draft of mining guidelines was released to the public. According to Ryan Richards, a member of the EWCLBG and a fellow at the Smithsonian Institution (Washington, DC), the challenges associated with guano mining can vary widely from region to region. In some areas, the miners are wellknown, well-organized, and deeply protective of their caves – at one site in Cambodia, for example, a local man had built a guardhouse at the entrance to a cave to defend his interests; this made it easy to know whom to talk to about the needs of the bats. At other locations, however, the identity of the miners is unknown. “It’s very context dependent”, Richards explains. In addition to the guidelines, a series of informative posters about the topic of bats and mining was developed for use in a wide variety of communities. Such initiatives are just the beginning, however; as David Waldien (Bat Conservation International, Austin, TX) cautions, “This is a process that’s going to take years”. n (477 ± 75 cm versus 208 ± 33 cm). In a second, larger arena with a 1m-high wall designed to ensure the beetles could see no land cues (eg treetops), the researchers timed how long they took to roll their balls to the edge. Those wearing the caps took significantly longer (124 ± 30 s versus 40 ± 15 s), their lines of progression much more meandering. The night sky was therefore providing orientation information, but what feature(s) was/were responsible? In planetarium experiments, the researchers showed the beetles to take the same time to leave the arena whether the full sky or just the strip of the Milky Way was projected. “In a nutshell, they use the line of light provided by the galaxy as their guide”, explains Warrant. Julián Santiago-Moreno (National Institute of Agricultural Research, Madrid, Spain) commented: “There must be some mightily confused beetles on overcast nights!” n www.frontiersinecology.org

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Poor net carbonate production threatens reefs Jane Bradbury New research suggests that contemporary carbonate production rates are substantially below historical values at reef locations across the Caribbean. “Many of these sites are producing carbonate at very low rates”, explains Chris Perry (University of Exeter, Exeter, UK), “and at some sites there is net erosion of carbonate, which implies the reefs are starting to break down. Our data suggest that recent ecological declines are suppressing the growth potential of Caribbean reefs.” Local factors, including overfishing, coastal development, and pollution, and global factors such as climate change are contributing to the major decline of coral reefs observed since the 1970s. To investigate the impact of this degradation on Caribbean reef growth, Perry and colleagues used a survey-based approach called “Reefbudget”, which estimates the reefs’ net annual carbonate production by quantifying the abundance of corals and other carbonate producers, and of bioeroders like parrotfish. The researchers compared

Brazil to inventory its forests Sarah Whitaker The Brazilian Forest Ministry reently announced that it will conduct a National Forest Inventory to provide information on forest resources countrywide. At present, Brazil’s forested lands – roughly equivalent to 5 million km2 – cover about 61% of the nation’s terrestrial extent. With an expected duration of 5 years, the landscape-scale inventory will rely on a broad set of measures, including field research and satellitebased imagery. Data will be sampled from 18 000 unique field locations equally distributed on a grid spanning across the country; non-forested areas will be included in order to be able to document future transitions of nonwww.frontiersinecology.org

current carbonate production estimates with those obtained before 1970, and with those going back 7000 years measured from coral reef cores. On average, current production rates were at least 50% lower than historical rates, and one-fifth of the sites surveyed had net negative carbonate production (Nat Commun 2013; doi:10.1038/ The branched coral Acropora palmata has been ncomms2409). “Scientists have measured decimated by disease and environmental disturbances. the carbonate budget of various reefs before”, comments marine eroders to continue to grow”, says ecologist Isabelle Côté (Simon Fraser marine ecologist John Bruno (UniUniversity, Burnaby, Canada), “but versity of North Carolina, Chapel this research gives us a first picture of Hill, NC), “but, because other facthe situation at a regional scale. tors that affect geological accretion What worries me is that many of the such as storms are not considered, budgets studied appear to be on a extrapolating these results into the knife-edge. Slight losses in live coral future is tricky”. All three experts note that or slight increases in erosion could tip them into the red, and both are although the local factors involved likely to happen as climate change in coral reef decline can be controlled relatively easily, global presproceeds.” “This attempt to estimate the cur- sures are harder to manage. But, says rent [carbonate] accretion and ero- Côté, “the best chance we can give sion rates in several Caribbean loca- reefs to be able to cope with climate tions suggests that some reefs have change is to limit the local pressures too little coral relative to the bio- on them as much as possible”. n forested land to forested land, and vice versa. At each site, variables such as tree presence, height, diameter, and species name will be collected; data on soil, herbaceous plants, and necromass will be collected as well. The surrounding vicinity will be assessed qualitatively to allow for a more general characterization of ecosystem type. Moreover, researchers plan to conduct interviews with people living near each sample point in order to determine how local human communities view and use the forests. During the 1980s, Brazil conducted an earlier forest assessment, one that focused primarily on timber stocks. The aim of the current inventory, however, is to inform public policy and also to assist in achieving Brazil’s 2009 objective of reducing deforestation by 80%

before the year 2020. According to Brazil’s Forest Service Director, Joberto Veloso de Freitas, regarding the inventory, “it is important to gather raw field data to improve estimates of biomass carbon in different pools and also to drive further research and strategic analysis by the Government.” Although some Brazilian states currently perform their own forest surveys for management-related purposes, government officials hope that the nationwide inventory will provide comprehensive information about forest diversity, health, and use, to help implement largescale conservation initiatives, to better inform future conservation policy, and to allow the country to participate more effectively in international environmental discussions. n © The Ecological Society of America

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