[Spatial and temporal variations of ecosystem service synergy and trade-off in Qinling Mountains, China]

The Qinling Mountains are an important ecological function area in China. Exploring the trade-offs and synergies of ecosystem services is important for ecological protection and sustainable development in the Qinling Mountains. In this study, we analyzed the spatio-temporal variations of land uses in the Qinling Mountains in 2000, 2010 and 2020 based on remote sensing, meteorological, and soil texture data. The amounts of carbon sequestration, water yield, habitat quality, and soil conservation were calculated with CASA, InVEST and RUSLE models. The relationships between its spatially heterogeneous characteristics and various ecosystem services were analyzed. The results showed that, from 2000 to 2020, the area of arable land and grassland in the study area continued to decrease, the area of forest and building land increased, and the change of water body and unused land was not noticeable. Carbon sequestration was high in the east and low in the west, with an increasing trend. Water production continued to decrease, showing a tendency of higher on the south slope and lower on the north slope. Habitat quality increased steadily, while soil conservation increased and then decreased. Ecosystem services varied across land classes and across ecosystems in the same land class. In general, there was a synergistic relationship between carbon sequestration and soil conservation, habitat quality and soil conservation, carbon sequestration, and habitat quality. There was trade-off between carbon sequestration and water production, soil conservation and water production, habitat quality, and water production. There were significant differences in the relationship between service volumes under different conditions. The results could reduce the risk of trade-offs and maximize overall benefits, and provide a reference for promoting ecologically high-quality development and achieving a win-win situation for natural resource management and human well-being.