Global change is impacting plant community composition, but the mechanisms underlying these changes are unclear. Using a dataset of 58 global change experiments, we tested the five fundamental mechanisms of community change: changes in evenness and richness, reordering, species gains and losses. We found 71% of communities were impacted by global change treatments, and 88% of communities that were exposed to two or more global change drivers were impacted. Further, all mechanisms of change were equally likely to be affected by global change treatments—species losses and changes in richness were just as common as species gains and reordering. We also found no evidence of a progression of community changes, for example, reordering and changes in evenness did not precede species gains and losses. We demonstrate that all processes underlying plant community composition changes are equally affected by treatments and often occur simultaneously, necessitating a wholistic approach to quantifying community changes.
Bibliographical noteFunding Information:
We thank the LTER Network for funding synthesis working groups in 2012 (National Science Foundation [EF 1545288] to MLA and KJK) and 2016 (National Science Foundation [EF 0553768] to KJK, MLA and KRW). This research would not be possible without all the work generosity of the researchers who provided data for this manuscript and the technical staff at these sites who assured that the long‐term integrity of these data are/were maintained. Not all of the researchers who contributed data to this project are listed as authors, so we specifically want to acknowledge their contributions: John Bates, John Blair, William Bowman, Nona Chiariello, Katherine Gross, Greg Houseman, Steven Pennings, Tony Svejcar, David Tilman, Roy Turkington, Zhuwen Xu and Qiang Yu. Funding sources for individual experiments included in the data synthesis can be found in Table S3 .
© 2021 The Authors. Ecology Letters published by John Wiley & Sons Ltd.
- data synthesis
- global change experiments
- herbaceous plants
- species gains
- species losses