Biodiversity loss a major threat to plant growth, researchers warn
If you thought that climate change and pollution are the only factors that affect our planet's ecosystems, think again. A new international research study suggests that the loss of biodiversity is also one of the triggers. The findings, presented in the journal Nature, underline the need for more action to be taken on the local, national and international fronts for safeguarding biodiversity. Researchers from Canada, Sweden and the United States launched this first-of-a-kind study comparing the effects of biological diversity loss on the anticipated effects of other anthropogenic environmental changes. 'Loss of biological diversity due to species extinctions is going to have major impacts on our planet, and we'd better prepare ourselves to deal with them,' explained one of the authors of the study, Professor Bradley Cardinale from the School of Natural Resources and Environment at the University of Michigan in the United States. 'These extinctions may well rank as one of the top five drivers of global change.' Since the early 1990s, researchers have identified the more productive role of biologically diverse ecosystems. Experts have become increasingly concerned that the growing rates of modern extinctions could weaken nature's ability to provide goods and services, including a stable climate, food and clean water. However, researchers have been unable to elucidate how loss of biodiversity measures against anthropogenic environmental changes impacting the health and productivity of ecosystems. 'Some people have assumed that biodiversity effects are relatively minor compared to other environmental stressors,' said lead author David Hooper of Western Washington University in the United States. 'Our new results show that future loss of species has the potential to reduce plant production just as much as global warming and pollution.' Using a suite of meta-analyses of published data, the team observed the effects of species loss on productivity (plant growth) and decomposition (plant death), both of which are important processes for all ecosystems. According to the researchers, negligible impacts on ecosystem plant growth will emerge in areas where local species loss in this century falls within the lower range of projects (i.e. loss of 1% to 20% of plant species). They added that changes in species richness will rank low relative to the impacts estimated for other environmental changes. Plant growth will drop between 5% to 10% in ecosystems where species losses fall within intermediate projections (21% to 40% of species). This result is similar to the anticipated impacts of climate warming and intensified ultraviolet radiation triggered by stratospheric ozone loss. Higher levels of extinction (41% to 60% of species) are comparable to the impacts of species loss ranked with those of several major drivers of environmental change, including 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,' Professor Hooper said. 'I think several of us working on this study were surprised by the comparative strength of those effects.' The team pointed out the importance of policymakers recognising the potential negative effects on biodiversity. 'The biggest challenge looking forward is to predict the combined impacts of these environmental challenges to natural ecosystems and to society,' said one of the authors of the paper, J. Emmett Duffy of the Virginia Institute of Marine Science in the United States. Experts from the University of Gothenburg in Sweden and McGill University and the University of British Columbia in Canada contributed to this study. Other American participants were the National Center for Ecological Analysis and Synthesis, the University of Vermont, Northern Arizona University and the University of California, Irvine.For more information, please visit: Nature:http://www.nature.com/Western Washington University:http://www.wwu.edu/
Countries
Canada, Sweden, United States