Abstract: Xinjiang is located in arid and semiarid areas. Understanding Xingjiang's ecosystems carbon budget and their responses to climate change is important for studying the dryland vegetation carbon sink in China and its contribution to terrestrial carbon balance. Based on the latest meteorological observations and the atmosphere-vegetation interaction model(AVIM2), the net ecosystem productivity(NEP)of Xinjiang from 1961 to 2015, with the spatial resolution of 0.05°×0.05° grids, were simulated and its responses to climate change were analyzed. The results show that the mean NEP of Xinjiang over the 55 years was 14.4 g C·m^-2, and the NEP has no significant trend during the studying periods. NEP decreased in about 40% areas of Xinjiang, and these areas were mainly distributed in the plain areas of the northern and southern sides of the Tianshan Mountains, where with dense population. The other 60% areas in Xinjiang experienced NEP increased. These areas are distributed in Kunlun and Tianshan Mountains and those sparse vegetated areas. NEP in Xingjiang was more sensitive to precipitation than to temperature. Although Xinjiang's averaged NEP fluctuated from sources to sinks as the yearly precipitation changed, the multiyear averaged NEP was positive, implying Xinjiang was the carbon sink area.

Key words: net ecosystem productivity(NEP), AVIM2, Xinjiang, climate change