Effects of Grazing and Climate Changes on Leymus Chinensis Grassland Ecosystem

摘要

Effects of human activity on terrestrial ecosystems have being drawn more and more attention with the development of global change study. As a case study, the responses of Leymus Chinensis grassland ecosystem in Songnen plain, Jilin Province to grazing and climate change were discussed based on CENTURY model and the field observed data. The results showed that grazing had seriously effect on soil organic matter and community production, especially overgrazing would decrease about 30.35% in soil organic carbon, 74.95% in aboveground biomass and 59.24% in belowground biomass. Under the condition of 2℃ increase in temperature, no matter what precipitation decreases or increases, soil organic carbon would decrease. Under 2℃ increase in temperature and 20% increase in precipitation, the biomass would increase about 60%. Moreover, grazing had more seriously influence on Leymus Chinensis grassland ecosystem than climate changes did. Thus, it is more important to find out strategies, methods and countermeasures for ensuring Leymus Chinensis grassland ecosystem sustainable development.