干旱区生态环境知识资源中心

The grassland ecosystem is of great significance in global carbon cycle under the condition of global change. The biomass of grassland is an important parameter in estimating carbon storage of grassland ecosystem, in order to analyze the relationship between plant yields and climatic factors, 22 years of plant yields and climate data were collected on the northern slope of the Tianshan Mountains region of western China. Using multiple regression analysis, it was clarified that fluctuation of climatic factors affected herbage yields and their periodical variation. The herbage yields were correlated significantly to the water factors especially the precipitation (p<0.01), but unrelated to the trend variable (the former year yield has little effects on the later) and other climatic factors. Our research demonstrated that the herbage yields had 4-year period similar to ecoclimatic factors, but with 114 period delay. These findings revealed further that the fluctuation of some climatic elements (precipitation particularly) was the crucial factor affecting the formation of herbage yields of natural grassland in arid and semiarid ecosystem. These results on periodical fluctuations of plant yields with the climate were important for the herdsmen to rectify their livestock population in grazing land. What's more, we can estimate the carbon storage in this area with the help of remote sensing technology and modelling method. The results will provide the scientific basis for the government to account grassland carbon balance and carbon storage in the future. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Conference ESIAT2011 Organization Committee.