Abstract: Net primary productivity (NPP) of the mountainous area in upper reaches and oasis areas in middle and lower reaches of Shiyang River basin was estimated using the Thornthwaite Memorial model. The spatial and temporal dynamics of NPP were analyzed by Sen’s slope method. Based on the sensitivity analysis, the contributions of main climate factors to NPP were estimated. The response of NPP to climate change was analyzed by setting four different climate scenarios. Subsequently, the changes of NPP in future were predicted. The results showed that climate had a tendency to be warm and wet from 1981 to 2015, with increasing NPP in the study area. The spatial heterogeneity of change trend of NPP was not significant, but the spatial heterogeneity of change magnitude was strong, with NPP increasing from the upper reaches to the lower reaches. NPP was mainly affected by precipitation, relative humidity, and net radiation. The “warm and wet” climate was beneficial to the vegetation growth, while the “cold and dry” climate was unfavorable to the vegetation growth. The changes in NPP depend on precipitation, with temperature affecting the amplitude of such changes. The NPP in Shiyang River basin is predicted to increase by 5.71%-7.83% in 2050.

Key words: Thousand-Island Lake, ecosystem services, valuation, economic evaluation