Print PagePlant 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.
Results/Conclusions
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.
