Long-term exposure to elevated CO₂ enhances plant community stability by suppressing dominant plant species in a mixed-grass prairie

Journal Article · Mon Oct 13 00:00:00 EDT 2014 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.1414659111· OSTI ID:1348417

Zelikova, Tamara Jane ^[1]; Blumenthal, Dana M. ^[2]; Williams, David G. ^[1]; Souza, Lara ^[3]; LeCain, Daniel R. ^[2]; Morgan, Jack ^[2]; Pendall, Elise ^[4]

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1. Univ. of Wyoming, Laramie, WY (United States)
2. U.S. Dept. of Agriculture, Fort Collins, CO (United States)
3. Univ. of Oklahoma, Norman, OK (United States)
4. Univ. of Wyoming, Laramie, WY (United States); Univ. of Western Sydney, Penrith (Australia)

Evaluating ecological responses to climate change is essential to predict ecosystem function under future climate scenarios. In a mixed-grass prairie, we use a multifactor field experiment to show that the effects of elevated CO2 and warming on plant community structure and productivity depend on interannual variation in precipitation. We also show that shifts in plant dominance patterns driven by elevated CO2 in a mixed-grass prairie ecosystem promoted biomass and compositional stability and resistance to interannual variation in precipitation. The economic value of grasslands is largely dependent on the relative abundance of key forage species. Thus, our results have implications for how we manage native grasslands in the face of changing climate. 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.

• Research Organization: Univ. of Wyoming, Laramie, WY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: SC0006973
• OSTI ID: 1348417
• Alternate ID(s): OSTI ID: 1454918
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Vol. 111, Issue 43; ISSN 0027-8424
• Publisher: National Academy of Sciences, Washington, DC (United States)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
climate change
elevated carbon dioxide
grassland
community stability
warming