Using a pattern-process-service-sustainability framework to clarify the relationship between regional ecosystem quality and sustainable development

The evaluation of ecosystem quality (EQ) is crucial for sustainable regional development. Existing studies have often focused on a single aspect of the evaluation of EQ, which cannot capture the whole picture of changes in EQ. Therefore, an urgent need exists to construct a comprehensive evaluation system for regional EQ and clarify the relationship between EQ and sustainable development level (SDL). This study takes the West Liao River Basin as an example, constructs a regional EQ evaluation index system based on the "pattern-process-service" framework, evaluates and analyzes the spatial and temporal evolution of EQ as well as the relationship between EQ and SDL in the basin from 2000 to 2020. The regional SDL is also analyzed by combining the indicator system with the United Nations Sustainable Development Goals (SDGs), analyzing the relationship between watershed EQ and SDL and its driving mechanism by using the coupling coordination degree model and Geodetector method and then exploring the strategies for sustainable management of watershed ecosystems. The spatial variation of EQ in the study area from 2000 to 2020 was found to be significant and characterized by increasing inter-annual changes; regions with a high EQ tended to have higher SDLs and SDL evaluation indicators contributed more to the coupling and coordination between EQ and SDL than EQ evaluation indicators. The study developed a regional EQ evaluation system under the perspective of ecosystem services, constructed a county-scale SDL evaluation system, and revealed the relationship between regional EQ and SDL. The evaluation results can provide decision-making references for sustainable regional management. In addition, the EQ evaluation system developed in this study is generalized and objective, thus being applicable to other watershed regions with complex landscape patterns.