Biodiversity Stabilizes Ecosystems During Climate Extremes

This article first appeared on Phys.Org Can biodiversity help protect ecosystems from extreme conditions? That question is much on the minds of scientists and policy makers as a changing climate brings more wildly swinging conditions at the same time human activities reduce the number of species available to produce food and oxygen and help keep our planet in balance.

Now, a study of 46 grasslands in North America and Europe points to a promising answer: Increasing plant diversity decreases the extent to which extremely wet or dry conditions disrupt grassland productivity.

"We've long known that biodiversity has a stabilizing effect on productivity over time," said lead author Forest Isbell, principle investigator on the project and associate director for the University of Minnesota's Cedar Creek Ecosystem Science Reserve, one of the study sites. "But we haven't been quite sure whether that's during extreme events, after them, or both. This research showed that diverse communities are more stable because they exhibit resistance during events."

Combining results across the 46 study sites, the researchers found that the higher the plant biodiversity, the lower the variability in productivity during wet or dry climate events. Overall, productivity of communities with only one or two species changed an average of 50 percent during events, while those with 16 to 32 species changed only half that much. Biodiversity did not, however, seem to strongly influence how quickly a site returned to normal productivity after wet or dry events...