Direct effects dominate responses to climate perturbations in grassland plant communities.
Theory predicts that strong indirect effects of environmental change will impact communities when niche differences between competitors are small and variation in the direct effects experienced by competitors is large, but empirical tests are lacking. Here we estimate negative frequency dependence, a proxy for niche differences, and quantify the direct and indirect effects of climate change on each species. Consistent with theory, in four of five communities indirect effects are strongest for species showing weak negative frequency dependence. Indirect effects are also stronger in communities where there is greater variation in direct effects. Overall responses to climate perturbations are driven primarily by direct effects, suggesting that single species models may be adequate for forecasting the impacts of climate change in these communities.
SYSU-Alberta Joint Lab for Biodiversity Conservation, State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Building No. 408, No. 135, Xingangxi Road, Guangzhou 510275, China.|Department of Wildland Resources and the Ecology Center, Utah State University, Logan, Utah 84322, USA.
Chengjin
C
Chu
Department of Wildland Resources and the Ecology Center, Utah State University, Logan, Utah 84322, USA.
Andrew R
AR
Kleinhesselink
USDA, ARS, Jornada Experimental Range and Jornada Basin Long Term Ecological Research, New Mexico State University, Las Cruces, New Mexico 88003, USA.
Kris M
KM
Havstad
School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona 85721, USA.
Mitchel P
MP
McClaran
USDA, ARS, Jornada Experimental Range and Jornada Basin Long Term Ecological Research, New Mexico State University, Las Cruces, New Mexico 88003, USA.
Debra P
DP
Peters
USDA-ARS, Fort Keogh Livestock and Range Research Laboratory, Miles City, Montana 59301, USA.
Lance T
LT
Vermeire
School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona 85721, USA.
Haiyan
H
Wei
Department of Wildland Resources and the Ecology Center, Utah State University, Logan, Utah 84322, USA.
Peter B
PB
Adler
D057231:Climate Change; D065948:Grassland; D008962:Models, Theoretical; D010944:Plants / Q000378:metabolism*