| Summary: | As a critical ecosystem type, wetlands have received extensive attention from scholars worldwide. Previous studies have mostly taken the entire wetland as the research object, and there is a lack of differentiated research on wetland subsystems. Ponds are a vital component of wetland ecosystems, and they are widely distributed, provide high ecological service value, and are related to many ecosystem functions; however, they have not attracted sufficient scholarly attention. This study divided ponds into three categories according to differences in geographic location, surrounding land-use types, and ecological service functions: ponds surrounding farmland, ponds around lakes, and ponds near towns. Taking county-level cities in the Jianghuai Ecological Economic Zone as the research area, a comprehensive evaluation system was established based on the external dangers and internal vulnerabilities of pit ponds. This evaluation method was based on the current wetland evaluation system, which considers actual pond characteristics, introduces indicators that characterize pond pollution, and conducts ecological risk assessments of ponds with different ecological service functions. The results demonstrate that (1) the ecological risks of pond wetlands in the northern part of the study area are higher than those in the south; (2) the ecological risks of cultivated land and pond wetlands around towns are less than those around lakes; (3) The primary risk sources of ponds with different ecological service functions vary. The small number of ponds surrounding farmland and ponds near towns, and their unstable structure and internal fragility are the main factors affecting their ecological risk assessments. Ponds around lakes are predominately affected by natural man-made external risk factors. © 2021 The Authors
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