Responses of an old-field plant community to interacting factors of elevated [CO2], warming, and soil moisture

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Journal of Plant Ecology

DOI:https://doi.org/10.1093/jpe/rtn026· OSTI ID:951083

Engel, Elizabeth C. ^[1]; Weltzin, Jake ^[2]; Norby, Richard J ^[2]; Classen, Aimee T ^[2]

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1. University of Tennessee, Knoxville (UTK)
2. ORNL

Aims The direct effects of atmospheric and climatic change factors atmospheric [CO2], air temperature, and changes in precipitation can shape plant community composition and alter ecosystem function, but it is essential to understand how these factors interact to make better predictions about how ecosystem may respond to change. We investigated the direct and interactive effects of [CO2], warming, and altered soil moisture in open-top chambers enclosing a constructed old-field community to test how the these factors shape plant communities. Materials and methods The experimental facility in Oak Ridge, Tennessee, USA made use of 4-m diameter open-top chambers and rain shelters to manipulate [CO2] (ambient, ambient + 300 ppm), air temperature (ambient, ambient + 3.5 C), and soil moisture (wet, dry). The plant communities within the chambers comprised seven common old-field species, including grasses, forbs, and legumes. We tracked foliar cover for each species and calculated community richness, evenness, and diversity from 2003-2005. Important findings This work resulted in three main results: 1) warming had species-specific effects on foliar cover that varied through time and were altered by soil moisture treatments; 2) [CO2] had little effect on individual species or the community; 3) diversity, evenness, and richness were influenced most by soil moisture, primarily reflecting the response of one dominant species. This experiment demonstrated that individualistic species responses to atmospheric and climatic change can alter community composition, and plant community response should be an important component of analyses of terrestrial ecosystem response. Prediction of plant community changes will remain difficult, however, given the occurrence of interactions between factors and the changes in response through time.

• Research Organization: Oak Ridge National Laboratory (ORNL); Oak Ridge National Environmental Research Park
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 951083
• Journal Information: Journal of Plant Ecology, Journal Name: Journal of Plant Ecology Journal Issue: 1 Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR
CLIMATIC CHANGE
COMMUNITIES
ECOSYSTEMS
FORECASTING
MOISTURE
RAIN
SHAPE
SHELTERS
SOILS
TERRESTRIAL ECOSYSTEMS
USA