Impact of wetland change on ecosystem services in different urbanization stages: A case study in the Hang-Jia-Hu region, China

Urbanization has had a profound impact on wetlands, and wetland conservation and restoration have attracted much attention. However, the detailed impacts of different urbanization and wetland changing processes on ecosystem services (ESs) are not well understood. Based on long-time series of remote sensing data (1990–2020), flood mitigation (FM), water purification (WP), carbon sequestration (CS), and biodiversity conservation (BC) were quantified in the Hang-Jia-Hu (HJH) region, China. According to the changing trend of urban land, the study period was divided into three urbanization stages: slow urbanization (1990–1998), rapid urbanization (1998–2013), and moderate urbanization (2013–2020). Regression analysis was used to explore the quantitative relationship between urbanization/wetland changes and ESs. The results showed that the urban land expansion rates in the slow urbanization, rapid urbanization, and moderate urbanization stages were 46.51 km2/yr, 100.62 km2/yr, and 70.87 km2/yr, respectively, and the corresponding wetland changing rates were 5.14 km2/yr, 19.54 km2/yr and −20.88 km2/yr, respectively. FM decreased in the slow and moderate urbanization stages and increased in the rapid urbanization stage, and WP increased in the slow and rapid urbanization stages and decreased in the moderate urbanization stage. Urbanization led to a decrease in FM, CS, and BC. Wetland restoration improved these ESs, while wetland loss caused a decline in multiple ESs in the slow and rapid urbanization stages. Wetland restoration partially offsets the negative effects of urbanization and wetland loss on ESs in the rapid urbanization stage. Urbanization and wetland changes have linear and nonlinear effects on ESs in different urbanization stages. Wetland restoration is an effective way to improve ESs in urbanization regions. This study can make an important contribution to sustainable wetland ecosystem development in urbanization regions.