Identifying priority conservation areas based on comprehensive consideration of biodiversity and ecosystem services in the Three-River Headwaters Region, China

The Three-River Headwaters Region (TRHR) is an ecological security shelter for southeastern China and East Asia. It is necessary to develop scientific land-use management strategies in the Three-River Headwaters Region to achieve the goal of sustainable land development. This study selected six vital ecosystem services (ESs) for the study area namely, water supply, carbon sequestration, soil retention, sand fixation, hydrological regulation, and flood mitigation to quantify and map the spatiotemporal distributions of these ecosystem services during 2000–2018. We also mapped the spatial distribution of biodiversity protection importance in the Three-River Headwaters Region using the MaxEnt model. We further identified the priority conservation areas through the combination of biodiversity and six ecosystem services with different area thresholds and compared the conservation efficiencies in the Sanjiangyuan National Park and the current protected areas in the Three-River Headwaters Region. In addition, we evaluated the relationships between ecosystem services and biodiversity protection importance and the impacts of eleven environmental factors (i.e., normalized difference vegetation index, elevation, slope, temperature, precipitation; wind speed, solar radiation, the proportion of forest land, the proportion of grassland, the proportion of cropland, and the proportion of wetland) on them. Finally, we identified the functional zones based on the ecosystem services-biodiversity bundles and proposed the corresponding management schemes. The results showed that the spatial distributions of six ecosystem services and biodiversity protection importance in the Three-River Headwaters Region were not spatially congruent. With the changes in the area thresholds in extracting priority conservation areas, the protection focus in the Sanjiangyuan National Park and the current protected areas should be updated accordingly. We identified eight ecosystem services-biodiversity bundles in the Three-River Headwaters Region and divided them into five ecological functional zones, based on which then the corresponding zoning optimization management schemes in each bundle and function zone were proposed. Comprehensive consideration of ecosystem services and biodiversity protection importance is insightful for other regions to conserve biodiversity and exploit natural resources simultaneously.