Evaluating ecological restoration outcomes in historical mine sites: Landscape connectivity and ecosystem service changes in the Xiang River Basin, China

Abstract

Ecological restoration in degraded mining areas is essential for improving ecosystem functions and promoting sustainable development in resource-dependent regions. However, integrated assessments of restoration outcomes remain limited, particularly in historically disturbed mine sites. These legacy sites often span large areas and face complex ecological challenges, making it critical to evaluate whether restoration efforts have effectively improved ecological structure and function. This study evaluates restoration outcomes at 756 historical mine sites in the Xiang River Basin from 2000 to 2020, focusing on four key ecosystem services: water yield, water purification, soil retention, and carbon sequestration. The evaluation is based on a systematic framework that incorporates three analytical dimensions: landscape pattern evolution, ecosystem service changes, and spatial coupling with key ecological spaces. Our results showed that landscape fragmentation around 84 % of mine sites was significantly reduced, with patch structures becoming more integrated and regular, particularly in areas with dense mine site distributions. Nevertheless, overall landscape connectivity and system stability remained relatively low. In terms of ecosystem services, 52 % of mine sites has experienced a decline in service capacity, with water yield and water purification services in the middle and lower reaches of the basin showing the most notable deterioration. Encouragingly, restoration efforts at several critical ecological nodes have achieved substantial outcomes, demonstrating the potential of precision-based ecological interventions and offering valuable experience for future regional ecological recovery. This study provides empirical evidence and a practical framework for implementing spatially targeted mine restoration strategies in watershed-scale planning.