Ecosystem effects of biodiversity loss could rival impacts of climate change, pollutionMay 03, 2012
The study is the first comprehensive effort to directly compare the impacts of biological diversity loss to the anticipated effects of a host of other human-caused environmental changes.
The results highlight the need for stronger local, national and international efforts to protect biodiversity and the benefits it provides, according to the researchers, who are based at nine institutions in the United States, Canada and Sweden.
"Loss of biological diversity due to species extinctions is going to have major impacts on our planet, and we better prepare ourselves to deal with them," said University of Michigan ecologist Bradley Cardinale, one of the authors. The study is scheduled for online publication in the journal Nature on May 2.
"These extinctions may well rank as one of the top five drivers of global change," said Cardinale, an assistant professor at the U-M School of Natural Resources and Environment and an assistant professor in the Department of Ecology and Evolutionary Biology.
Studies over the last two decades have demonstrated that more biologically diverse ecosystems are more productive. As a result, there has been growing concern that the very high rates of modern extinctions - due to habitat loss, overharvesting and other human-caused environmental changes - could reduce nature's ability to provide goods and services like food, clean water and a stable climate.
But until now, it's been unclear how biodiversity losses stack up against other human-caused environmental changes that affect ecosystem health and productivity.
"Some people have assumed that biodiversity effects are relatively minor compared to other environmental stressors," said biologist David Hooper of Western Washington University, the lead author of the Nature paper. "Our new results show that future loss of species has the potential to reduce plant production just as much as global warming and pollution."
In their study, Hooper and his colleagues used combined data from a large number of published studies to compare how various global environmental stressors affect two processes important in all ecosystems: plant growth and the decomposition of dead plants by bacteria and fungi. The new study involved the construction of a data base drawn from 192 peer-reviewed publications about experiments that manipulated species richness and examined the impact on ecosystem processes.
The global synthesis by Hooper and his colleagues found that in areas where local species loss this century falls within the lower range of projections (loss of 1 to 20 percent of plant species), negligible impacts on ecosystem plant growth will result, and changes in species richness will rank low relative to the impacts projected for other environmental changes.
In ecosystems where species losses fall within intermediate projections (21 to 40 percent of species), however, species loss is expected to reduce plant growth by 5 to 10 percent, an effect that is comparable in magnitude to the expected impacts of climate warming and increased ultraviolet radiation due to stratospheric ozone loss.
At higher levels of extinction (41 to 60 percent of species), the impacts of species loss ranked with those of many other major drivers of environmental change, such as ozone pollution, acid deposition on forests, and nutrient pollution.
"Within the range of expected species losses, we saw average declines in plant growth that were as large as changes seen in experiments simulating several other major environmental changes caused by humans," Hooper said. "I think several of us working on this study were surprised by the comparative strength of those effects."
The strength of the observed biodiversity effects suggests that policymakers searching for solutions to other pressing environmental problems should be aware of potential adverse effects on biodiversity, as well, the researchers said.
Still to be determined is how diversity loss and other large-scale environmental changes will interact to alter ecosystems. "The biggest challenge looking forward is to predict the combined impacts of these environmental challenges to natural ecosystems and to society," said J. Emmett Duffy of the Virginia Institute of Marine Science, a co-author of the paper.
Authors of the Nature paper, in addition to Hooper, Cardinale and Duffy, are: E. Carol Adair of the University of Vermont and the National Center for Ecological Analysis and Synthesis; Jarrett E.K. Byrnes of the National Center for Ecological Analysis and Synthesis; Bruce Hungate of Northern Arizona University; Kristen Matulich of University of California Irvine; Andrew Gonzalez of McGill University; Lars Gamfeldt of the University of Gothenburg; and Mary O'Connor of the University of British Columbia and the National Center for Ecological Analysis and Synthesis.
Funding for the study included grants from the National Science Foundation and the National Center for Ecological Analysis and Synthesis.
"This analysis establishes that reduced biodiversity affects ecosystems at levels comparable to those of global warming or air pollution," said Henry Gholz, program director in the National Science Foundation's Division of Environmental Biology, which funded the research.
University of Michigan
Related Biodiversity Current Events and Biodiversity News Articles
Tigers, pandas and people a recipe for conservation insight
The first big revelation in conservation sciences was that studying the people on the scene as well as nature conservation was crucial. Now, as this science matures, researchers are showing that it's useful to compare apples and oranges.
How evolutionary principles could help save our world
The age of the Anthropocene--the scientific name given to our current geologic age--is dominated by human impacts on our environment.
Diversified farming practices might preserve evolutionary diversity of wildlife, say Stanford and Berkeley biologists
As humans transform the planet to meet our needs, all sorts of wildlife continue to be pushed aside, including many species that play key roles in Earth's life-support systems.
LSU Scientists Lead Research on Speciation in the Tropics
In a study that sheds light on the origin of bird species in the biologically rich rainforests of South America, LSU Museum of Natural Science Director and Roy Paul Daniels Professor in the Department of Biological Sciences, Robb Brumfield, and an international team of researchers funded by the National Science Foundation, or NSF, published a paper this week challenging the view that speciation - the process by which new species are formed - is directly linked to geological and climatic changes to the landscape.
Discovery paves the way for a new generation of chemotherapies
A new mechanism to inhibit proteasomes, protein complexes that are a target for cancer therapy, is the topic of an article published in the journal Chemistry & Biology.
Agricultural revolution in Africa could increase global carbon emissions
Productivity-boosting agricultural innovations in Africa could lead to an increase in global deforestation rates and carbon emissions, a Purdue University study finds.
Testing the fossil record
Does the fossil record paint an accurate picture of the history of life? Geobiologist Bjarte Hannisdal at the University of Bergen believes that fossils can tell us a lot about the evolution of life, but also about the evolution of Earth itself.
Near-extinct African amphibians 'invisible' under climate change
An international team of researchers has found that the majority of threatened species are 'invisible' when using modern methods to predict species distributions under climate change.
Climate change to increase forest fire danger in Europe
Climate change is expected to contribute to a dramatic increase in forest fire damage in Europe, but better forest management could mitigate the problem, according to new research from the International Institute for Applied Systems Analysis (IIASA).
Coffee genome sheds light on the evolution of caffeine
The newly sequenced genome of the coffee plant reveals secrets about the evolution of man's best chemical friend: caffeine.
More Biodiversity Current Events and Biodiversity News Articles