Spatiotemporal Changes and Trade-Offs/Synergies in Island Ecosystem Services: A Case Study of the Zhoushan Archipelago

With the rapid development of the social economy, island ecosystem services (ESs) are facing increasingly severe disruptions from human activities. This study constructs an integrated analytical framework of spatiotemporal changes–driving mechanisms–trade-offs/synergies. It aims to support regional sustainability by assessing the spatiotemporal patterns of ESs in the Zhoushan Archipelago, identifying key ecological functional zones and areas with high trade-offs and synergies, in order to formulate management strategies for long-term ecological balance. The results indicate that all four ESs in the Zhoushan Archipelago exhibited declining trends from 2000 to 2020. Spatially, these four ESs collectively exhibit a distribution pattern characterized by higher values in the south and lower values in the north. The cold spot and hot spot analysis results indicate that both the significant cold spot areas and significant hot spot areas have expanded, with noticeable changes occurring on Zhoushan Island, Daishan Island, and Liuheng Island. Based on these spatiotemporal variation characteristics, ecological functional zoning was conducted. The results show that the area of ecologically vulnerable zones has significantly increased, while the area of other functional zones has decreased. Driving factor analysis reveals that the land use/land cover, annual average precipitation, digital elevation model, slope, and normalized difference vegetation index have the most significant impact on the spatial heterogeneity of ESs. Furthermore, trade-off/synergy analysis among ESs was conducted. Spatially, high-trade-off areas are primarily located in central Zhoushan Island, Liuheng Island, Jintang Island, Daishan Island, and Sijiao Island. High-synergy areas are mainly distributed in northern Zhoushan Island, Qushan Island, Taohua Island, and the Ma’an Archipelago. These findings provide a scientific basis for the ecological conservation and restoration of the Zhoushan Archipelago, offering significant reference value for promoting sustainable development in island regions.