New Evidence Of Impact Of Global Changes On Remote Tropical RainforestsFebruary 06, 2004Scientists have shed new light on the impact of global environmental changes on remote tropical forests with studies that show that the rates of growth and death of trees in pristine forests across the Amazon have accelerated substantially in recent decades. The scientists also demonstrate that the tropical forests globally have warmed by half a degree in the last 20 years and warn that this is expected to increase by a further three to eight degrees by the end of the century, with dangerous implications for the forests, climate change and human welfare. The papers are published in a themed issue, 'Tropical Forests and Global Atmospheric Change', of Philosophical Transactions B, a learned journal published by the Royal Society*. In three papers, scientists report that pristine forests across the Amazon Basin have almost doubled their rates of tree growth and death in recent decades. This appears to have led to an increase in biomass in these pristine forests. Several papers in the themed issue debate the possible cause of these changes and whether they will persist or reverse. The most likely culprits are identified as increases in atmospheric concentrations of carbon dioxide and surface air temperatures, and possible continent-wide changes in sunshine. "Whilst this increase in biomass may well have helped to slow the rate of global climate change so far, a number of computer model simulations presented in the issue, suggest that this 'carbon sink' cannot be taken for granted. The process could be reversed in as short a space of time as the next two decades by the combined effects of deforestation and global warming," says Dr Oliver Phillip of the University of Leeds, one of the scientists and co-editor of the publication. Whilst some rainforests are increasing in biomass, others appear to be already breaking up under a combination of climatic and human pressure. Two papers explore how the combination of climate change and the fragmentation of rainforest settlement 'opens up' the remaining forest and makes it increasingly vulnerable to forest fires. One paper - Ecological responses to El Nino-induced surface fires in central Brazilian Amazonia: Management implications for flammable tropical forests, by Jos Barlow and Carlos Peres - reports new field data showing that these fires cause big declines in large fruit-eating monkeys and insect-eating birds. All contributing scientists are agreed that there is an urgent need for conservation action to prevent fragmentation and to create forest corridors to give some species a chance of moving as the climate changes. Ultimately, saving the world's remaining rainforests also requires a committed effort to move away from burning fossil fuels. The new research presented here suggests this shift needs to happen sooner rather than later. Dr Yadvinder Malhi, co-editor, concludes: "This research shows that conservation of the remaining rainforests will need to take into account the new pressures that global atmospheric change is placing on these forests. In the 21st century, we are moving into a human-made atmospheric and climatic situation that has not been experienced on earth for at least 20 million years. We are deeply concerned with how the earth's most biodiverse ecosystems will respond to these changes." The papers in this issue are: Spatial patterns and recent trends in the climate of tropical forest regions, by Yadvinder Malhi and James Wright Fingerprinting the impacts of global change on tropical forests, by Simon Lewis, Yadvinder Malhi and Oliver Phillips Pattern and process in Amazon tree turnover 1976-2110, by Oliver Phillips and co-authors Concerted Changes in Tropical Forest Structure and Dynamics: Evidence from 50 South American long-term plots, by Simon L Lewis and co-authors Increasing biomass in Amazonian forest plots, by Timothy Baker and co-authors Tropical forests and the global carbon cycle: impacts of atmospheric CO2, climate change and rate of deforestation, by Wolfgang Cramer and co-authors Ecological responses to El Nino-induced surface fires in central Brazilian Amazonia: management implications for flammable tropical forests, by Jos Barlow and Carlos Peres Forest-climate interactions in fragmented tropical landscapes, by William Laurance Tropical forests and global atmospheric change: a synthesis, by Yadvinder Malhi and Oliver Phillips Sources or sinks? The responses of tropical forests to current and future climate and atmospheric composition, by D Clark Error propagation and scaling for tropical forest biomass estimates, by J Chave; R Condit; S Aguilar; A Hernandez, S Lao and R Perez Some aspects of ecophysical and biogeochemical responses of tropical forests to atmospheric change, by J Chambers and W Silver Contrasting simulated past and future responses of the Amazonian forest to atmospheric chance, by S Cowling; R Betts; P Cox; V Ettwein; C Jones; M Maslin, S Spall Through enhanced tree dynamics CO2 enrichment may cause tropical forests to lose carbon, by C Korner Responses of Amazonian ecosystems to climatic and atmospheric CO2 changes since the last glacial maximum, by F Mayle; D Beerling; W Gosling; M Bush Historical climate change and speciation: neotropical seasonally dry forest plants show patterns of both tertiary and quaternary diversification, by R Pennington; M Lavin; D Prado; C Pendry; S Pell; C Butterworth Tropical forests and global atmospheric change: a synthesis, by Yadvinder Malhi and Oliver Phillips | |||||||||||||||||||||
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Related Tropical Forests News Articles Bad sign for global warming: Thawing permafrost holds vast carbon pool Permafrost blanketing the northern hemisphere contains more than twice the amount of carbon in the atmosphere, making it a potentially mammoth contributor to global climate change depending on how quickly it thaws. Tahitian vanilla originated in Maya forests, says UC Riverside botanist he origin of the Tahitian vanilla orchid, whose cured fruit is the source of the rare and highly esteemed gourmet French Polynesian spice, has long eluded botanists. Known by the scientific name Vanilla tahitensis, Tahitian vanilla is found to exist only in cultivation; natural, wild populations of the orchid have never been encountered. Extinction most likely for rare trees in the Amazon rainforest Common tree species in the Amazon will survive even grim scenarios of deforestation and road-building, but rare trees could suffer extinction rates of up to 50 percent, predict Smithsonian scientists and colleagues in the Aug. 12 issue of the journal Proceedings of the National Academy of Science. The drivers of tropical deforestation are changing, say scientists A shift from poverty-driven to industry-driven deforestation threatens the world's tropical forests but offers new opportunities for conservation, according to an article coauthored by William Laurance of the Smithsonian Tropical Research Institute in Panama. Vine invasion? UWM ecologist looks at coexistence of trees and lianas Among the hundreds of species of woody vines that University of Wisconsin-Milwaukee ecologist Stefan Schnitzer has encountered in the tropical forests of Panama, the largest has a stalk nearly 20 inches in circumference. Extinction threat growing for mankind's closest relatives Mankind's closest relatives - the world's monkeys, apes and other primates - are disappearing from the face of the Earth, with some literally being eaten into extinction. A bee's future as queen or worker may rest with parasitic fly Strange things are happening in the lowland tropical forests of Panama and Costa Rica. A tiny parasitic fly is affecting the social behavior of a nocturnal bee, helping to determine which individuals become queens and which become workers. Insect warning colors aid cancer and tropical disease drug discovery Brightly colored beetles or butterfly larvae nibbling on a plant may signal the presence of chemical compounds active against cancer cell lines and tropical parasitic diseases, according to researchers at Smithsonian's Tropical Research Institute in Panama. Looming tropical disaster needs urgent action A major review by University of Adelaide researchers shows that the world is losing the battle over tropical habitat loss with potentially disastrous implications for biodiversity and human well-being. Scientists may have solved an ecological riddle A team of scientists may have solved the riddle of why plants that work with bacteria to convert atmospheric nitrogen gas into an essential biological nutrient (ammonia) tend to prevail in the world's tropical regions rather than higher latitudes. More Tropical Forests News Articles |
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