title: Long-term exposure to elevated CO2 enhances plant community stability by suppressing dominant plant species in a mixed-grass prairie.
abstract: Climate controls vegetation distribution across the globe, and some vegetation types are more vulnerable to climate change, whereas others are more resistant. Because resistance and resilience can influence ecosystem stability and determine how communities and ecosystems respond to climate change, we need to evaluate the potential for resistance as we predict future ecosystem function. In a mixed-grass prairie in the northern Great Plains, we used a large field experiment to test the effects of elevated CO2, warming, and summer irrigation on plant community structure and productivity, linking changes in both to stability in plant community composition and biomass production. We show that the independent effects of CO2 and warming on community composition and productivity depend on interannual variation in precipitation and that the effects of elevated CO2 are not limited to water saving because they differ from those of irrigation. We also show that production in this mixed-grass prairie ecosystem is not only relatively resistant to interannual variation in precipitation, but also rendered more stable under elevated CO2 conditions. This increase in production stability is the result of altered community dominance patterns: Community evenness increases as dominant species decrease in biomass under elevated CO2. In many grasslands that serve as rangelands, the economic value of the ecosystem is largely dependent on plant community composition and the relative abundance of key forage species. Thus, our results have implications for how we manage native grasslands in the face of changing climate.
authors.affiliation: Department of Botany, University of Wyoming, Laramie, WY 82071; tzelikov@uwyo.edu.
authors.forename: Tamara Jane
authors.initials: TJ
authors.lastname: Zelikova
authors.affiliation: Rangeland Resources Research Unit, Agricultural Research Service, US Department of Agriculture, Fort Collins, CO 80526;
authors.forename: Dana M
authors.initials: DM
authors.lastname: Blumenthal
authors.affiliation: Department of Botany, University of Wyoming, Laramie, WY 82071;
authors.forename: David G
authors.initials: DG
authors.lastname: Williams
authors.affiliation: Oklahoma Biological Survey & Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019; and.
authors.forename: Lara
authors.initials: L
authors.lastname: Souza
authors.affiliation: Rangeland Resources Research Unit, Agricultural Research Service, US Department of Agriculture, Fort Collins, CO 80526;
authors.forename: Daniel R
authors.initials: DR
authors.lastname: LeCain
authors.affiliation: Rangeland Resources Research Unit, Agricultural Research Service, US Department of Agriculture, Fort Collins, CO 80526;
authors.forename: Jack
authors.initials: J
authors.lastname: Morgan
authors.affiliation: Department of Botany, University of Wyoming, Laramie, WY 82071; Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW 2751, Australia.
authors.forename: Elise
authors.initials: E
authors.lastname: Pendall
mesh_terms: D000704:Analysis of Variance; D018533:Biomass; D002245:Carbon Dioxide / Q000494:pharmacology*; D057231:Climate Change; D017753:Ecosystem; D006109:Poaceae / Q000187:drug effects* / Q000254:growth & development*; D011891:Rain; D013045:Species Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide
keywords: climate change; community stability; elevated carbon dioxide; grassland; warming