A new NASA-led study seven years in the making has confirmed that natural forests in the Amazon remove more carbon dioxide from the atmosphere than they emit, therefore reducing global warming. This finding resolves a long-standing debate about a key component of the overall carbon balance of the Amazon basin.The Amazon’s carbon balance is a matter of life and death: living trees take carbon dioxide out of the air as they grow, and dead trees put the greenhouse gas back into the air as they decompose. The new study, published in Nature Communications on March 18, is the first to measure tree deaths caused by natural processes throughout the Amazon forest, even in remote areas where no data have been collected at ground level.Fernando Esprito-Santo of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the study, created new techniques to analyze satellite and other data. He found that each year, dead Amazonian trees emit an estimated 1.9 billion tons (1.7 billion metric tons) of carbon to the atmosphere. To compare this with Amazon carbon absorption, the researchers used censuses of forest growth and different modeling scenarios that accounted for uncertainties. In every scenario, carbon absorption by living trees outweighed emissions from the dead ones, indicating that the prevailing effect in natural forests of the Amazon is absorption.Until now, scientists had only been able to estimate the Amazon’s carbon balance from limited observations in small forest areas called plots. On these plots, the forest removes more carbon than it emits, but the scientific community has been vigorously debating how well the plots represent all the natural processes in the huge Amazon region. That debate began with the discovery in the 1990s that large areas of the forest can be killed off by intense storms in events called blowdowns.Esprito-Santo said that the idea for the study arose from a 2006 workshop where scientists from several nations came together to identify NASA satellite instruments that might help them better understand the carbon cycle of the Amazon. In the years since then, he worked with 21 coauthors in five nations to measure the carbon impacts of tree deaths in the Amazon from all natural causes — from large-area blowdowns to single trees that died of old age. He used airborne lidar data, satellite images, and a 10-year set of plot measurements collected by the University of Leeds, England, under the leadership of Emanuel Gloor and Oliver Phillips. …Read more
Sep. 11, 2013 — Peru’s cloud forests are some of the most biologically diverse ecosystems in the world. A profusion of tree and plant species as well as one third of Peru’s mammal, bird and frog species make their home in these perennially wet regions, located along the eastern slopes of the Andes Mountains. The high elevation (6,500-11,000 feet), and remote location of these areas makes them some of the hardest to reach and therefore hardest to study ecosystems in the world. To date, scientists only believe a fraction of cloud forest tree and plant species have been discovered.This massive array of underexplored biodiversity will face an unprecedented threat before the end of the century.Now, researchers at Wake Forest University in Winston-Salem, N.C. have pieced together startling new evidence that shows rapid 21st century warming may spell doom for tree species in Peruvian cloud forests, with species losing 53-96 percent of their populations.Stuck in a Hot PlaceThe habitats of most Andean plants-and therefore the habitats of the organisms that use them for food and shelter- are determined largely by temperature. Temperatures change quickly on the slopes of the Andes due to the region’s steep terrain. This means the vast majority of trees and plants only can live in a range that extends a few hundred meters.”I could be standing among a group of one tree species and throw a rock completely across their ranges,” says David Lutz, the paper’s lead author and a former postdoctoral associate at Wake Forest University. Lutz, who is now a post-doctoral research associate at Dartmouth College in New Hampshire, says this means cloud forest trees are particularly sensitive to climate change.Historically, Andean cloud forest seedlings sprout higher in elevation during periods of global warming. However, an unprecedented rate of projected temperature gain in the region over the next century, 5 degrees Celsius, will have them going upslope faster than ever before, says Miles Silman, professor of Biology at Wake Forest University. …Read more
Sep. 5, 2013 — Metro Manila — the world’s 10th largest megacity and 6th largest conurbation, based on official statistics — is not a place one would normally expect to discover new species, even in a country that is known as a biodiversity hotspot.In a 83-hectare green island amidst the unnatural ocean of countless human-made edifices, researchers of the Ateneo de Manila University have discovered a tiny new species of aquatic beetle, aptly named Hydraena ateneo. It was named after the University, a 154-year-old Jesuit-run institution that is recognized as one of the premier universities in the Philippines and in the region. The international open access scientific journal Zookeys has published the paper about the unusual discovery in its latest issue [329: 9 (2013)]. The publication of the fact is just timely, given that the university’s Department of Biology is celebrating its 50th anniversary this year.During field training in November 2012, Biology students and a faculty member of the Department of Biology sampled small creeks, ponds, and pools in wooded areas within their sprawling university campus. The group found seven species of water beetles, of which one was a new record for the entire island of Luzon and another was Hydraena ateneo.Arielle Vidal, at the time of the training enrolled in the Department’s B.S. Life Sciences program, says: “I was so amazed that there are new species even in the Ateneo Campus in the middle of Manila. Then I was sure that I wanted to write my thesis on a taxonomic topic.” Kimberly Go, her thesis partner, adds: “Then we pushed through and investigated a remote river catchment in Mindoro. We found several new species of the same genus there, too.”Their thesis adviser and author of the recent paper, Associate Professor Dr. Hendrik Freitag, explains: “The Long-palped Water Beetles (genus Hydraena) are in fact one of the most overlooked and diverse genera of aquatic beetles. …Read more
Aug. 15, 2013 — A study spearheaded by the Wildlife Conservation Society and the University of Minnesota has shown that the world’s largest owl — and one of the rarest — is also a key indicator of the health of some of the last great primary forests of Russia’s Far East.The study found that Blakiston’s fish owl relies on old-growth forests along streams for both breeding and to support healthy populations of their favorite prey: salmon. The large trees provide breeding cavities for the enormous bird, which has a two-meter (six-foot) wingspan. And when these dead, massive trees topple into adjacent streams, they disrupt water flow, forcing the gushing river around, over, and under these new obstacles. The result is stream channel complexity: a combination of deep, slow-moving backwaters and shallow, fast-moving channels that provide important microhabitats critical to salmon in different developmental stages.The study appears in the August issue of the journal Oryx. Authors include Jonathan Slaght of the Wildlife Conservation Society, R. J. Gutiérrez of the University of Minnesota, and Sergei Surmach of the Institute of Biology and Soils (Russian Academy of Sciences).The authors studied the foraging and nesting characteristics of Blakiston’s fish owl in Primorye, Russia, where they looked at nesting habitat over 20,213 square kilometers (7,804 square miles). They found that large old trees and riparian old-growth forest were the primary distinguishing characteristics of both nest and foraging sites.The authors say that management and conservation of old-growth forests is essential for sustaining this species because they are central to the owls’ nesting and foraging behavior. Moreover, conservation of Primorye’s forests and rivers sustains habitat for many other species: including eight salmon and trout species that spawn there; some of the 12 other owl species found in Primorye; and mammals like the endangered Amur (or Siberian) tiger, Asiatic black bear, and wild boar. …Read more
July 23, 2013 — Scientists from the Universities of Stirling, Oxford, Queensland and the Wildlife Conservation Society warn that current hunting trends in Central African forests could result in complete ecological collapse.The authors maintain that the current rate of unsustainable hunting of forest elephants, gorillas and other seed-dispersing species threatens the ability of forest ecosystems to regenerate, and that landscape-wide hunting management plans are needed to avoid an environmental catastrophe.The study appears in the latest version of Philosophical Transactions of The Royal Society B. The authors include: K.A. Abernethy of the African Forest Ecology Group of Stirling University; L. Coad of the University of Queensland and the University of Oxford; G. Taylor of the University of Oxford; M. E. Lee of the Wildlife Conservation Research Unit and University of Oxford; and Fiona Maisels of the Wildlife Conservation Society and the African Forest Ecology Group.”Humans have lived in the forests of Central Africa for thousands of years, until recently practicing subsistence hunting for the needs of their communities,” said Kate Abernethy, lead author of the study. “Over the past few decades, this dynamic has drastically changed. Much of the hunting is now commercially driven, and species that play important ecological functions are being driven to local extinction.”The researchers conducted a review of more than 160 papers and reports on the region’s wildlife declines, hunting trends, and land-use analyses by humans. The authors found troubling trends that threaten the very fabric of rainforest ecosystems. …Read more
July 17, 2013 — A study published in the July 17, issue of the journal PLOS ONE found that more than 80% of tropical forests in Malaysian Borneo have been heavily impacted by logging.The Malaysian states of Sabah and Sarawak were already thought to be global hotspots of forest loss and degradation due to timber and oil palm industries, but the rates and patterns of change have remained poorly measured by conventional field or satellite approaches. A research team from the University of Tasmania, University of Papua New Guinea, and the Carnegie Institution for Science documented the full extent of logging in this region.The team used the Carnegie Landsat Analysis System-lite (CLASlite) to reveal the vast and previously unmapped extent of heavily logged forest. CLASlite’s high-resolution satellite imaging uncovered logging roads in Brunei and in the Malaysian states of Sabah and Sarawak on the island of Borneo.CLASlite, developed by Carnegie’s Greg Asner and team, has the unique ability to convert satellite images of seemingly dense tropical forest cover into highly detailed maps of deforestation and forest degradation. The user-friendly monitoring system has been made available to hundreds of governments, nongovernmental organizations, and academic institutions for use in mapping tropical forests.Analysis of satellite imagery collected from 1990 and 2009 over Malaysian Borneo showed approximately 226,000 miles (364,000 km) of roads constructed throughout the forests of this region. Nearly 80% of the land surface of Sabah and Sarawak was impacted by previously undocumented, high-impact logging or clearing operations. This finding contrasted strongly with neighboring Brunei, where 54% of the land area maintained intact unlogged forest.Team leader Jane Bryan said: “There is a crisis in tropical forest ecosystems worldwide, and our work documents the extent of the crisis on Malaysian Borneo. Only small areas of intact forest remain in Malaysian Borneo, because so much has been heavily logged or cleared for timber or oil palm production. Rainforests that previously contained lots of big old trees, which store carbon and support a diverse ecosystem, are being replaced with oil palm or timber plantations, or hollowed out by logging.”Only 8% and 3% of land area in Sabah and Sarawak, respectively, was covered by intact forests in designated protected areas. Very few forest ecosystems remain intact in Sabah or Sarawak. But Brunei has largely excluded industrial logging from its borders and has been comparatively successful in protecting its forests.Greg Asner commented: “The results are sobering. …Read more
July 1, 2013 — In the past decade, China has sunk some impressive numbers to preserve its forests, but until now, there hasn’t been much data to give a true picture of how it has simultaneously affected both the people and the environment.Michigan State University, partnered with the Chinese Academy of Sciences, has capitalized on their long history of research in the Wolong Nature Reserve to get a complete picture of the environmental and socioeconomic effects of payments for ecosystem services programs.”Performance and prospects of payments for ecosystem services programs: evidence from China” has been published in the Journal of Environmental Management. In it, Wu Yang, a doctoral student in Michigan State University’s Center for Systems Integration and Sustainability and center director Jianguo “Jack” Liu, the Rachel Carson Chair in Sustainability, outline the wins and losses in one of the world’s richest areas of biodiversity, and home to the endangered giant pandas.China’s tally: $15 billion to ban logging encourage new forests; $32 billion to persuade 32 million rural households to return 8.8 million hectares of cropland back to forest.The group examined both the people and the environment from as big a picture as trends of the forest from decades of land cover maps, to surveying individual households to understand how their behaviors changed as policies were introduced. Payments for ecosystem services programs — programs in which people were given incentives to change their behavior so the forest around them could recover — have been an enormous effort in China and worldwide.The work found that China’s offering people incentives to change how they live to boost the environment did benefit the forest and the environment — but not without a toll on the people who live there.The article emphasizes the importance of integrating local conditions and understanding underlying mechanisms to enhance the performance of payments for ecosystem services programs. The article also notes that understanding some of the impacts raises questions for future policy — about whether such policies could be made more efficient, is it ethical to make conservation gains at the cost of people’s livelihoods, cultural identity and other issues.In addition to Yang and Liu, the article was written by CSIS members Wei Liu, a former doctoral student; assistant professor Andrés Viña, research associate Junyan Luo and former doctoral student Guangming He. Also contributing were Zhiyun Ouyang from the Chinese Academy of Science and Hemin Zhang of China’s Center for Giant Panda Research and Conservation.The work was supported by the National Science Foundation, NASA,Michigan State University’s Environmental Science and Policy Program, and Graduate Office.Read more
May 28, 2013 — A new study, published 28 May in the open access journal PLOS Biology, has revealed the potential importance of rare species in the functioning of highly diverse ecosystems. Using data from three very different ecosystems — coral reefs, tropical forests and alpine meadows — a team of researchers led by David Mouillot at the University of Montpellier 2, France, has shown that it is primarily the rare species, rather than the more common ones, that have distinct traits involved in unique ecological functions. As biodiversity declines, these unique features are therefore particularly vulnerable to extinction because rare species are likely to disappear first.
“These unique features are irreplaceable, as they could be important for the functioning of ecosystems if there is major environmental change,” explained Dr Mouillot.
Biodiverse environments are characterized by a large number of rare species. These rare species contribute to the taxonomic richness of the area, but their functional importance in ecosystems is largely unknown. Represented by few individuals or distributed over narrow geographic areas, rare species are generally considered to have little influence on the functioning of an ecosystem compared with more common species. Indeed, it is often assumed that they fulfill the same ecological roles as those of common species but have less impact because of their low abundance; a phenomenon known as ‘functional redundancy’. This redundancy suggests that rare species merely serve as an “insurance” policy for the ecosystem, in the event of an ecological loss.
To test this, the team of researchers analyzed the extent to which rarer species in the three different ecosystems performed the same ecological functions as the most common ones. They examined biological and biogeographical information from 846 reef fish, 2979 alpine plants and 662 tropical trees and found that most of the unique and vulnerable functions, carried out via a combination of traits, were associated with rare species.
Examples of such species supporting vulnerable functions include the giant moray (Gymnothorax javanicus), a predatory fish that hunts at night in the labyrinths of coral reefs; the pyramidal saxifrage (Saxifraga cotyledon), an alpine plant that is an important resource for pollinators; and Pouteria maxima, a huge tree in the rainforest of Guyana, which is particularly resilient to fire and drought. Not only are they rare but they have few functional equivalents among the more common species in their respective ecosystems.
“Our results suggest that the loss of these species could heavily impact upon the functioning of their ecosystems,” said Dr Mouillot. “This calls into question many current conservation strategies.”
The work emphasizes the importance of the conservation of rare species, even in diverse ecosystems. Rare species are more vulnerable and serve irreplaceable functions, explained Dr Mouillot: the preservation of biodiversity as a whole — not just the most common species, but all those who perform vulnerable functions — appears to be crucial for the resilience of ecosystems.
“Rare species are not just an ecological insurance,” he said. “They perform additional ecological functions that could be important during rapid transitions experienced by ecosystems. The vulnerability of these functions, in particular biodiversity loss caused by climate change, highlights the underestimated role of rare species in the functioning and resilience of ecosystems. Our results call for new experiments to explicitly test the influence of species rarity and the uniqueness of combinations of traits on ecological processes.” This line of research will also inform the lively debate about the relationship between biodiversity and ecosystem functioning.Read more