Bridging Ecosystem Value and Decision-Making: GEP Accounting in Nanhua County, China, and Pathways for Green Policy

Abstract

Abstract

Establishing effective mechanisms for recognizing and realizing ecosystem value is a central challenge in linking ecological conservation with sustainable development. Gross Ecosystem Product (GEP) accounting has emerged as an important tool for quantifying ecosystem service contributions, yet its application at the county scale—particularly in mountainous regions—remains limited. Taking Nanhua County in southwestern China as a representative case, this study develops a county-level GEP accounting framework tailored to complex topography and forest-dominated landscapes. By integrating biophysical models (InVEST, RUSLE, and SCS-CN) with market-based and replacement cost valuation methods, provisioning, regulating, and cultural services were systematically assessed for the year 2024. Results show that the total GEP reached 163.25 billion CNY, with regulating services accounting for 93.17%. Provisioning services were mainly supported by forestry and specialty agriculture, while cultural services were driven by ecotourism and landscape-related benefits. Spatial analysis revealed pronounced heterogeneity, with high-value GEP areas concentrated in forested southern mountains and lower values in central basins and urbanized zones. These findings highlight the ecological structure underpinning county-level ecosystem value and demonstrate the potential of GEP accounting to support spatial prioritization and comparative assessment. While subject to uncertainty inherent in ecosystem service valuation, the framework provides an indicative basis for exploring pathways that link ecological protection with green development in similar mountainous regions.