Assessment of multiple ecosystem services and interrelation-ships in Forest-rich regions: a case study of Guilin, China

Ecosystem services (ES) are fundamental to achieving human well-being. To systematically evaluate ES and their interrelationships in forest-enriched regions, this study takes Guilin, a representative forest-rich area in China, as the study area and develops an integrated coupling model for the comprehensive measurement and interaction analysis of provisioning, regulating, and cultural ES. The InVEST model was used to quantify provisioning and regulating ES. A discrete choice experiment (DCE) was applied to estimate the economic value of cultural ecosystem services (CES), and participatory geographic information systems (PPGIS) were employed to assess its spatial distribution. Based on these results, a spatial analytic geometry model was introduced to calculate the coordination deviation degree (CDD) and coordination transformation degree (CTD), which, respectively, characterize the synergy/trade-off relationships and the comprehensive development level among the three ES types. Finally, a spatial econometric model was used to identify the main influencing factors. The results show that provisioning ES in Guilin are generally at a medium level, with higher values in the southern and central regions and lower levels in the north; regulating ES are relatively high, exhibiting higher levels in the east and west but lower values in the central area; the economic value of CES varies considerably across space, forming a distinct spatial gradient. At both municipal and county levels, the coordination among the three types of ES remains relatively high, while the comprehensive development level is comparatively low. Further analysis reveals that forest coverage and GDP exert significant positive effects on ES, whereas temperature, terrain, population density, and industrial structure have negative effects. This study provides a feasible analytical framework for CES research, effectively captures the interrelationships among provisioning, regulating, and cultural ES, and offers valuable insights for forest ecosystem management.