COS 21-8 - Composition of C3 and C4 species regulates ecosystem response to climate warming

Tuesday, August 9, 2011: 10:30 AM
6A, Austin Convention Center
Shuli Niu1, Rebecca A. Sherry1, Xuhui Zhou2 and Yiqi Luo3, (1)Department of Botany and Microbiology, University of Oklahoma, Norman, OK, (2)Institute of Biodiversity, Fudan University, Shanghai, China, (3)Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK

Plant community structure has been shown to determine ecosystem functions. However, it is not well understood how plant species composition regulates responses of ecosystem processes to climate warming. We conducted two experiments with warming and clipping, respectively, in a C4-dominated (C4: 72% of above ground biomass) and a C3-dominated (C3: 72.4% of above ground biomass) grassland in the southern Great Plains of North America.


Warming significantly increased ecosystem respiration (ER) but caused little changes in gross primary productivity (GPP) and net ecosystem exchange (NEE) in the C4-dominated grassland. In contrast, warming significantly increased NEE but decreased both GPP and ER in the C3-dominated grassland. The different responses of the carbon exchanges between the two experiments can be primarily explained by composition of C3 and C4 species in the two communities. This is, warming-induced changes in NEE, GPP and ER were positively correlated with C4 biomass proportion but negatively with C3 biomass proportion. These results highlight the importance of species composition in determining ecosystem response to climate change.

Copyright © . All rights reserved.
Banner photo by Flickr user greg westfall.