Abstract: Evaluating the effectiveness of ecological protection and restoration is essential for optimizing management strategies and achieving sustainable outcomes. We developed a multiscale assessment framework of “regionunit-site” with corresponding indicators. The assessment at the region scale focuses on the changes in ecosystem structure and patterns, that at the unit scale pays attention to the changes in ecological disturbance and the completion of performance goals, and that at the site scale focuses on the changes in ecosystem quality and services. Following this framework, we quantitatively evaluated the comprehensive effectiveness of ecological protection and restoration in Jiangmen City, Guangdong Province during 2013-2018 (phase 1) and 2018-2023 (phase 2). The results showed that both phases exhibited ecological land loss (>4%) and connectivity index reduction (>10%) at the region scale, indicating the deterioration of ecosystem structure and pattern. At the unit scale, although some improvement had been achieved in solving ecological problems, the development  intensities of the three restoration units-soil conservation, water quality improvement, and coastal protection-had not been effectively controlled in both stages. At the site scale, while most areas showed enhanced ecosystem quality in both phases, the proportion of areas with excellent and good performance of ecosystem services was less than 25%. There were notable degradation of ecosystem services in the middle and lower reaches of the Tanjiang River and along the coast of the Xijiang River. In general, most areas had experienced significant improvement in ecological protection and restoration effectiveness from phase 1 to 2. The proportion of excellent-effectiveness regions increased from 2.27% to 12.83%, mainly distributed in central-south and northern regions. The proportion of low-effectiveness regions decreased from 52.17% to 26.57%, primarily in coastal zone, the middle and lower reaches of the Tanjiang river and the Xijiang river, and western mountains. These findings underscore the necessity to prioritize ecological land conservation and enhance coastal/riverine ecosystem services in Jiangmen. The proposed multi-scale assessment framework effectively identifies spatial heterogeneity in ecological protection and restoration outcomes as well as the problems, demonstrating the potential for broader application in ecosystem management.

Key words: ecological protection and restoration, multi-scale study, effectiveness evaluation, ecosystem services, Jiangmen City