Trade-offs and synergies of ecosystem services in Anhui Province, China based on functional zone identification.

Clarifying the spatial layout of ecological functional zones and the evolution patterns of trade-offs and synergies among multiple ecosystem services is helpful to formulate region-specific management strategies and is fundamentally important for scientific ecosystem management and sustainable development. We analyzed the spatiotemporal variations of six ecosystem services (ES) in Anhui Province from 1990 to 2020, including biodiversity maintenance, water yield, habitat quality, carbon storage, food supply, and soil retention. The multiple ecosystem service landscape index was used to assess comprehensive ecosystem service capacity. The self-organizing mapping algorithm was used to identify ecosystem service bundles. We conducted ecological functional zoning and investigated the trade-off and synergy among ES at both regional scale and within different service bundles. The results showed that during 1990-2020, construction land and forest exhibited increasing trends, increased by 121.8% and 1.2% respectively, while cropland, grassland, water, and unused land all decreased. Habitat quality and carbon storage showed decreasing trends, while the other four ESs exhibited overall increasing trend. Food supply displayed a pattern of low in the south and high in the north, whereas all other ESs showed a pattern of high in the south and low in the north. Based on the identified ecosystem service bundles, the study area was classified into three functional zones. The grain production area accounted for the largest proportion, while the ecological conservation area and the ecological transition area maintained roughly equal proportions. The ecological transition zone expanded faster than the ecological conservation zone. At the regional scale, there were trade-offs between food supply and other ESs, while there were synergies in the remaining five ESs. Due to the influences from human activities, land use types and climate change, the trade-off and synergy relationships among ESs within different service bundles exhibited varying degrees of heterogeneity compared to those at the regional scale.