Differences in the Biomass of Ecological System of Wetlands in the Eastern Margin of the Qinghai-Tibet Plateau

The eastern margin of the Qing-hai-Tibetan Plateau boasts plenty of wetlands,and also is the source area of major rivers in China. And therefore the changes of the wetlands in this region will largely influence the inland ecological environment. The study sites were selected in the eastern Tibetan Plateau and they were:Rouergai wetland,Jiuzhaigou Nature Reserve wetland and Hongkou Nature Reserve wetland. Investigations were made on the aboveground biomass of wetland plant communities in the study sites and the results indicated that there was a significant correlation (p < 0.01) between the study sites; and the underground biomass in Ruoergai wetland had a significant correlation (p < 0.05) among other sites. The biomass at higher altitudes was larger than that at lower altitudes. There was a significant higher above-ground biomass (F=9.05,P < 0.01) in Ganhaizi wetland than that in Jiuzhaigou wetland,and their distance was close; while there was no significant correlation in underground biomass among three sites. In terms of carbon sequestration,the order was Ganhaizi Wetland > Ruoergai Wetland > Jiuzhaigou Wetland > Hongkou wetland. The main factor impacting the biamass change should be the types of wetlands and then followed by human activities.