Exploring ecosystem services and interconnections in nearshore islands for spatial planning: Insights from China.

As climate change, urbanization, and marine exploitation intensify, understanding nearshore island ecosystem services (IESs) is essential for ensuring ecological protection and sustainable development. This study maps the spatiotemporal dynamics of six key ecosystem services (ESs) across 295 nearshore Chinese islands, including food production (FP), water yield (WY), soil conservation (SC), carbon storage (CS), and habitat quality (HQ) (2000-2022), and tourism and recreation (TR) (2012-2022). Using spatial autocorrelation, Slope trend analysis, per-pixel Pearson correlation, and K-means clustering, the study quantifies the trade-offs and synergies, identifies constraint characteristics, and delineates ecological functional zones for island classification. The results indicate that FP and TR generally increased, while WY, SC, HQ, and CS declined on most islands-by 52.20 %, 68.47 %, 71.86 %, and 69.49 %, respectively. Spatially, FP increases in the south and stays stable in the north, while WY shows the opposite pattern. TR remains constant on 79.32 % of islands. FP has the strongest trade-off with SC, but this trend is weakening, whereas the FP-WY trade-off is intensifying. The trade-off between WY and HQ has significantly increased. Meanwhile, SC exhibits an increasing synergy with both CS and HQ, with CS-HQ synergy being the most pronounced. Among the constraint patterns, the SC-HQ trough-type, WY-SC linear-type, and TR-WY peak-type are the most representative. By analyzing ecosystem service bundles (ESBs), 68.95 % of nearshore islands are classified as Ecological Protection Category (EPC), 19.05 % as Agricultural Planting Category (APC), and only 12.00 % as Production and Livelihood Category (PLC). This study provides a novel perspective on island spatial planning, promoting integrated management and sustainable development.