Many terrestrial plant communities, especially forests, have been shown to lag in response to rapid climate change. Grassland communities may respond more quickly to novel climates, as they consist mostly of short-lived species, which are directly exposed to macroclimate change. This study reports the rapid response of grassland communities to climate change in the California Floristic Province (CFP). Using 829,337 occurrence records, 15 long-term community composition datasets, and 3 global change experiments, the researchers analyzed community compositional shifts. They found significant shifts towards species associated with warmer and drier locations at rates comparable to climate warming and drying. These shifts were consistent across observations and experiments, contrasting with lagged responses observed in forest ecosystems and suggesting greater biodiversity changes than expected in the near future.

Kai Zhu, Yiluan Song, Josephine C. Lesage, Justin C. Luong, James W. Bartolome, Nona R. Chiariello, Joan Dudney, Christopher B. Field, Lauren M. Hallett, Michele Hammond, Susan P. Harrison, Grey F. Hayes, Richard J. Hobbs, Karen D. Holl, Peter Hopkinson, Loralee Larios, Michael E. Loik, Laura R. Prugh