Trade-off and synergistic of ecosystem services supply and demand based on socio-ecological system (SES) in typical hilly regions of south China

The balance between the supply and demand of ecosystem services (ESSD) is important for sustainable regional development. The hilly regions of south China have rich natural resources and are rapidly being urbanized, which significantly impacts sustainable development in the region. Therefore, how to analyze ESSD from the perspective of social ecology is imperative. Ganzhou region, which is a typical hilly region in southern China, as an example, this paper creatively integrated ESSD into the social-ecological system (SES) framework, analyzed the spatial and temporal changes of ESSD in 2005, 2010, 2015, and 2020, and constructed a system of indicators from the SES, and analyzed the driving factors of ESSD, so as to provide a reference for balancing ESSD. Based on the classical SES framework proposed by Ostrom, this study first analyses the social-ecological system profile of the Ganzhou region at the macro-scale and constructs an SES indicator system. The innovation of combining the SES framework and ecosystem services lies in integrating the social and ecosystem perspectives and merging these two concepts to understand better and manage the relationship between humans and the natural environment. It provides a comprehensive analytical approach and decision support tool for achieving sustainable development. Our results demonstrate that: (1) From 2005 to 2020, ecosystem services in the study area were highly valued, lower areas had homogeneous distribution characteristics, total demand displayed spatial differentiation, there were high-value areas in the midwest, and low-value areas were concentrated in the region's boundary. (2) There are obvious supply and demand deficits in the southeast and east of the study area, while supply–demand is equal in the north and supply exceeds demand in other regions. From 2005 to 2020, the overall coupling coordination degree of ESSD in the study area was lower than 0.5, indicating a mild to moderate imbalance. (3) The supply of ecosystem services (ESS) was primarily driven by carbon storage, habitat quality, and water yield, while the demand was primarily driven by forest and grassland areas. Factors related to the ecosystem, resource unit, resource system, social system, governance system, and actor all have experienced two-factor interactions, which can explain up to 99% of ESSD. Based on the SES framework, this paper studies the relationship between ESSD in typical areas of the southern hills to provide a reference for research on ESSD in relevant areas and provide a scientific basis for the Chinese government to evaluate ecological protections and improve compensation policies, which is important for ensuring China's ecological security.