Effects Of Plant Diversity On Greenhouse Gas Emissions In Wetland

Wetlands are important "sink" and "source" of greenhouse gas in the atmosphere, and plant species in wetlands affect the absorption and release of greenhouse gas. However, few studies have tested the effects of plant species richness on greenhouse gas emissions in wetland ecosystem, In order to test how different plant species and species richness affect greenhouse gas emissions in wetland ecosystem, we assembled four species richness with 1,2,4 and 8 emergent plant species, respecitively. No significant difference was found in biomass among four species richness. The cumulative emissions of CO2, CH4 and N2O were significantly affected by different plant species. However, plant species richness did not significantly affect the cumulative emissions of CO2, CH4 and N2O. Significant difference was found in the cumulative emissions of CO2, CH4 and N2O between different kinds of communities only when these communities contained either Lythrum salicaria, Iris tectorum, Acorus calamus, Typha minima, Polygonum lapathifolium or Butomus umbellatus; Pontederia cordata, Acorus calamus or Butomus umbellatus; and Pontederia cordata, Typha minima or Polygonum lapathifolium, respectively. Both aboveground biomass and total biomass of different plant species were positivley related to CO2 cumulative emissions while they were negativley realted to N2O cumulative emissions. There was a positive relationship between communities biomass and CO2 cumulative emissions. Therefore, plant species composition can affect greenhouse gas emissions in wetlands. Future studies are needed to detect if there is a significant effect of plant species richness on greenhouse gas emissions in wetland communities consisting of species of different functional groups.