Comprehensive Assessment of Sustainable Development of Terrestrial Ecosystem Based on SDG 15—A Case Study of Guilin City

Sustainable Development Goal 15 (SDG 15) specifically targets the protection, restoration, and sustainable use of terrestrial ecosystems, including forests, wetlands, mountains, and drylands, along with their biodiversity. This study localizes the SDG 15 indicator system and integrates geospatial and statistical data to construct an enhanced evaluation framework for assessing the sustainable development of terrestrial ecosystems at the county level. The proposed system encompasses key indicators such as forest coverage rate, terrestrial biodiversity, sustainable forest management, land degradation neutrality, mountain biodiversity, and mountain green cover index. Using Guilin City as a study area, the ecological status of each county was assessed over the period 2010 to 2020, providing valuable insights to guide ecological conservation and sustainable development efforts. The main results are as follows: (1) Spatial heterogeneity is evident in the distribution of key biodiversity areas, which are concentrated in the northern and southeastern mountainous regions of Guilin. (2) Land degradation during the assessment period is notably smaller than during the baseline period, though a significant gap remains toward achieving land degradation neutrality. (3) Sustainable development scores for terrestrial ecosystems show an overall upward trend across counties, but the poor performance in sustainable forest management affects the comprehensive sustainable development of terrestrial ecosystems in Guilin. The localized SDG 15 indicator system proposed in this paper can effectively quantify changes in terrestrial ecosystems and visualize their spatial distribution, and can effectively serve as a model for other sustainable development areas.