Ecological benefit assessment and impact factor analysis of restoration in the Hanjiang River basin, Guangdong, based on ecosystem services

Abstract

Rapid industrialization and urbanization have fueled socioeconomic growth, but have also caused ecological degradation. Therefore, ecological restoration has become essential for maintaining environmental quality. Evaluating the effectiveness of ecological restoration is critical for determining whether objectives have been met and for guiding further ecosystem management decisions. This study evaluated the ecological benefits and influencing factors of restoration in the middle and upper reaches of the Hanjiang River network in Guangdong Province, China, from 2000 to 2023. Redundancy analysis identified the key factors affecting ecological benefits and their relative contributions. The results indicated that the value of ecosystem services in the Hanjiang River network increased from 2000 to 2008, decreased from 2009 to 2020, and increased again from 2021 to 2023. Ecological benefits followed a generally decreasing trend, improving from 2000 to 2013, declining from 2014 to 2020, and improving from 2021 to 2023. The “Integrated Protection and Restoration Project of Mountains, Waters, Forests, Farmlands, Lakes, Grasslands and Soil in the Middle and Upper Reaches of the Han River in the Nanling Mountains of Guangdong Province” implemented from 2021 to 2023 is of great significance for enhancing the value of regional ecosystem services. The key factors affecting ecological benefits included pollution from mining and timber harvesting, which was strongly negatively correlated with restoration benefits (contributing 20.6%), and long-term restoration measures such as soil and water conservation, pollutant control, and river management, which contributed 71.6%. These findings emphasize that tailored ecological restoration measures that address local environmental issues are crucial for restoring ecosystem structure and improving ecosystem services.