Tradeoffs and synergies of ecosystem services in western mountainous China: A case study of the Bailongjiang watershed in Gansu, China

Abstract

The Bailongjiang watershed of Gansu is an important water conservation and ecological barrier area in the upper reaches of Yangtze River. It is necessary to reveal the tradeoffs and synergies of ecosystem services (ESs) for the "win-win" of watershed ecological system and social eco-nomy development. Based on the InVEST model, four typical ESs including soil conservation (SC), water conservation (WC), food supply (FS), and habitat quality (HQ) were assessed, and the multi-scale tradeoffs and synergies of ESs and its drivers were analyzed by correlation and root mean square deviation (RMSD). The results showed that there were significant synergies among SC, WC, and HQ, and a significant tradeoff between FS and HQ, SC, WC, respectively. The areas with high tradeoff intensity between the three pairs of synergistic services (SC-WC, SC-HQ, WC-HQ), and between FS and HQ were mainly concentrated in the steep forest area of middle-high mountain in Wenxian, Diebu and Zhouqu. The high intensity of tradeoffs between FS-SC, FS-WC were mainly concentrated in the gentle apricus farming and pastoral areas of middle-low mountain in Tanchang and Wudu. The spatial variation of land use/cover caused by human activities was an important factor affecting the degree of ES tradeoffs and its scale effect.