Exploring Trade-Offs and Synergies in Social–Ecological System Services across Ecological Engineering Impact Regions: Insights from South China Karst

Abstract

Karst ecosystems have become complex social–ecological systems (SESs) as a result of the interventions of large-scale ecological restoration programs, and the ecosystem services (ESs) that provide regional well-being can, to some extent, be described as social–ecological system services (S–ESs). Understanding the relationships among multiple S–ESs and exploring their drivers are essential for effective ecological management in karst areas, especially in regions differently affected by ecological engineering programs. Taking South China Karst (SCK) as a study area, we first identified two regions as comparative boundaries, namely significant engineering impact regions (SEERs) and non-significant ecological engineering impact regions (NEERs). Then we used ES assessment models, Spearman correlation, and optimal parameter geographic detector to identify the supply capacity, trade-offs/synergies, and their drivers of six types of S–ESs in SEERs and NEERs. The findings included: (1) SEERs were predominantly concentrated in the central and southern SCK regions, accounting for 33.98% of the total SCK area, with the most concentrated distribution observed in Guizhou and Guangxi. (2) Within the entire SCK, six S–ESs maintained a relatively stable spatial distribution pattern over time, with the most pronounced increase in soil conservation and a slight decrease in water retention, and the S–ES hotspots were more concentrated within the SEERs. (3) Most S–ES pairs within SEERs were optimized synergistically, with lower trade-off intensity and higher synergy intensity compared to NEERs. (4) S–ES pairs were affected by the interactions between the natural and socio-economic factors, with land use changes playing a crucial role, and natural factors were difficult to predict but cannot be ignored. Based on the results, we propose different SES sustainable development suggestions, with a view to providing theoretical support for the optimization of SES functions and the consolidating of integrated ecological construction.