Temporal and spatial changes and trade-offs analysis of urban wetland ecosystem services: a case study of Xixi wetland in Hangzhou

Elucidating temporal and spatial changes in urban wetland ecosystem services, especially of long time series and at high resolution, is vitally important for the formulation of urban wetland protection policy．InVEST model and economic valuation methods were applied to land-use maps with high resolution, to estimate changes in ecosystem services and trade-offs between ecosystem of Xixi wetland from 1984 to 2018．Ecosystem services showed an overall declining trend except carbon sequestration, and wetlands continued to deteriorate．An increase trend of carbon sequestration and biodiversity protection services was identified inside park, but a decrease trend outside the park．Rise in precipitation and expansion in impervious ground resulted in higher water yield and nutrient export inside and outside the park．Contradiction between tourism development and ecological protection has not been completely alleviated．Analysis of interactions between pairs of ecosystem services identified that trade-offs occurred mainly between water yield and carbon sequestration services, biodiversity protection services, recreation and cultural services, especially around urban impervious ground．