HEALTH EVALUATION OF WETLANDS DISTRIBUTED ALONG URBAN-RURAL GRADIENTS BASED ON V-IBI

The expansion of urban areas has led to the encroachment of built-up areas on surrounding wetlands, adversely affecting the health of these ecosystems. Assessing the health status of wetlands becomes imperative for devising targeted policies to mitigate the impact of urbanization. Plant diversity is regarded as critical indicator of their overall health. In this study, three wetlands situated along urban -rural gradients in Hangzhou City were evaluated for ecological health using the vegetation -based index of biotic integrity (V-IBI) method, employing diversity survey data. The results revealed the selection of eight core indicators from a pool of 47 candidates that were used to calculate V-IBI values. This study found a decline in ecological health along the urban -rural gradients. The sampling points in the case wetlands were categorized into four groups based on V-IBI: poor (I), general (II), good (III), and healthy (IV). Progressing from the city center outward, 52.5%, 50%, and 4.8% of samples from Xixi Wetland, Tongjian Lake, and Qingshan Lake, respectively were classified as healthy. A positive linear relationship between plant richness and wetland health, coupled with species redundancy, was observed. Augmenting the number of plant species in wetlands proves conducive to maintaining their health and enhancing resilience against external interference.