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Title: Climate change effects on plant biomass alter dominance patterns and community evenness in an experimental old-field ecosystem

Journal Article · · Global Change Biology

Atmospheric and climatic change can alter plant biomass production and plant community composition. However, we know little about how climate change-induced alterations in biomass production affect plant community composition. To better understand how climate change will alter both individual plant species and community biomass we manipulated atmospheric [CO2], air temperature and precipitation in a constructed old-field ecosystem. Specifically, we compared the responses of dominant and subdominant species to our treatments, and explored how changes in plant dominance patterns alter community evenness over two years. Our study resulted in four major findings: 1) All treatments, elevated [CO2], warming and increased precipitation, increased plant biomass and the effects were additive rather than interactive, 2) Plant species differed in their response to the treatments, resulting in shifts in the proportional biomass of individual species, which altered the plant community composition; however, the plant community response was largely driven by the responses of the dominant species, 3) Precipitation explained most of the variation in plant community composition among treatments, and 4) Changes in precipitation caused a shift in the dominant species proportional biomass that resulted in higher community evenness in the dry relative to wet treatments. Interestingly, compositional and evenness responses of the subdominant community to the treatments did not always follow the responses of the whole plant community. Our data suggest that changes in plant dominance patterns and community evenness are an important part of community responses to climate change, and generally, that compositional shifts can have important consequences for the functioning of terrestrial ecosystems.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge National Environmental Research Park
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
986777
Journal Information:
Global Change Biology, Vol. 16, Issue 10; ISSN 1354-1013
Country of Publication:
United States
Language:
English