Spatial differences of the supply of multiple ecosystem services and the environmental and land use factors affecting them

A practical knowledge of the amount or supply level of multiple ecosystem services is the key prerequisite for enhancing local ecological stability and securing the well-being of humanity. We studied the supplies of four ecosystem services: grain provisioning, meat provisioning, water conservation, and soil retention at the county level in the Jinghe watershed in northwestern China. The spatial differences of the supply of four ecosystem services were studied using two indices, the Total Ecosystem Services (TES) and Trade-Offs (TO) indices. Then, the environmental and land use factors affecting the spatial differences were also analyzed. The results show that large spatial differences exist in the supplies of multiple ecosystem services, in which the TES and TO indices varied by as much as six and 12 times from one area to another, respectively. Precipitation was the primary constraint on the total supply of multiple ecosystem services. However, environmental factors had little impact on the ecosystem service trade-offs, although the type of land use had significant impacts. An increase in the spatial extent of grassland area resulted in reduced trade-offs and enhanced the supply of multiple ecosystem services. A spatial increase in farmland had opposite effects. This case study provides a new perspective on identifying where and how to enhance multiple ecosystem services.