Management Strategies Based on the Spatial Heterogeneity of Ecosystem Service Trade-Offs and Synergies at the Township Scale in Hainan Island, China

Abstract

The spatial heterogeneity of ecosystem services (ESs) and their trade-off and synergy mechanisms are the core scientific basis for regional ecological management and spatial optimization. However, existing studies have largely focused on large-scale assessments, with limited attention given to the interactions of ecosystem services at the township scale. This study, based on the township scale of Hainan Island, used the InVEST model and net primary production (NPP) to simulate the spatiotemporal changes of five ESs—habitat quality (HQ), carbon storage (CS), water yield (WY), soil retention (SR), and oxygen release (OR)—from 2000 to 2020. Additionally, self-organizing mapping, machine learning, and multi-scale geographically weighted regression methods were employed to systematically identify the trade-offs and synergy structures of ESs, as well as the dominant driving factors. The study also proposed differentiated spatial management strategies. The results show that: (1) All five ESs exhibited a declining trend, with particularly severe degradation in coastal regions. In contrast, relatively stable high-value clusters were observed in the central mountainous regions, indicating significant spatial differentiation and imbalance in service provision. (2) The key synergistic bundle was spatially aligned with the protection zones of the national forest park, representing areas with the most complete ecological functions. Conversely, the city bundle was concentrated in peri-urban and development-pressured zones, showing pronounced functional degradation. (3) The woodland proportion was identified as the dominant positive driver, while construction land proportion and human footprint were key negative drivers. ESs exhibited pronounced spatial non-stationarity in response to these variables. Based on the spatial heterogeneity of ESs at the township scale, it is recommended to implement differentiated ecological protection and land control strategies, including strengthening the management of protection redlines in core areas and constructing ecological corridors and compensation mechanisms in peripheral areas, in order to enhance the overall resilience and service supply capacity of regional ecosystems.