Nonlinear response of community stability to ambient climate determines
response direction of community stability to warming and grazing
Abstract
The impacts of human-driven environmental changes on the stability of
natural grasslands have been assessed by comparing differences between
manipulative warming and grazing plots and reference plots. However,
little is known about whether or how ambient climate regulates the
effects of manipulative treatments. A 36-year observational dataset
shows that there is a nonlinear response of community stability to
ambient climate. Manipulative warming and grazing decrease community
stability with experiment duration through an increase in legume
coverage and/or decrease in species asynchrony, due to exceeding the
threshold of background annual mean air temperature with decreasing
background annual mean air temperature through time during the 10-year
experiment period. Moreover, the temperature sensitivity of community
stability is more sensitive under the ambient treatment than under the
manipulative treatments. Therefore, our study emphasizes the importance
of the context dependency of the response of community stability to
human-driven environmental changes.