Changes of wetland area, ecosystem service value and their driving forces in Changsha City from 1991 to 2020

Wetland transformations emerge from complex human-natural interactions, exerting a profound influence on wetland ecosystem service values and regional sustainability. This investigation employed multi-temporal Landsat imagery (7 epochs) and field datasets from 1991 to 2020, supplemented with socioeconomic records from the Changsha City Statistical Yearbook, to analyze wetland area changes and quantify ecosystem service values (ESVs). The study systematically examined drivers of area changes through integrated analysis of socioeconomic indicators (population growth, GDP expansion, urbanization rate, agricultural land use) and environmental parameters (mean annual temperature, precipitation patterns). Key findings revealed persistent declines in both wetland extent and associated ESVs over three decades. Total wetland area decreased by 17.6% (51 000 to 42 000 hm²), predominantly through pond wetland conversion. Concurrently, ESVs declined by 18.3% (2.02 to 1.65 billion Yuan), with regulatory services constituting the largest contribution and provisioning services the smallest. Among wetland types, pond wetland demonstrated the highest service value, followed by riverine wetland, with lake-reservoir wetland exhibiting the lowest valuation. Regression analysis identified significant negative correlations (p<0.05) between total wetland area and key socioeconomic drivers (population density, GDP growth, and agricultural expansion). These relationships highlight the dominant role of anthropogenic pressures over natural climatic factors in wetland transformations, particularly the conversion of peri-urban wetland ecosystems to meet demands for urban expansion and agricultural development.