Analysis of Factors Influencing Plant Diversity in Urban Wetlands Based on Structural Equation Model

Abstract Urban wetlands play a vital role within the urban ecosystem, and the application of ecological design methods in urban wetland planning and design can significantly enhance their biodiversity and improve the overall service functions of urban ecosystems. This study focuses on three urban wetlands: Xixi Wetland in the core area, Tongjian Lake Wetland in the fringe area, and Qingshan Lake Wetland in the suburban area. Meanwhile, four design factors of water quality protection, shoreline maintenance, ecological facilities, and plant diversity were investigated, together with 34 ecological design methods, based on statistics of the plant species composition of urban wetlands. Using structural equation modeling to screen out the design methods and influence paths that have an appreciable impact on plant diversity. We found variations in the three urban wetlands' plant compositions and ecological design strategies: (1) 336 species of plants were recorded in Xixi Wetland, 179 in Qingshan Lake Wetland, and 112 in Tongjian Lake Wetland; (2) the number of ecological design methods applied in Xixi Wetland is significantly higher than that of Tongjian Lake Wetland and Qingshan Lake Wetland; (3) ten ecological design methods in Qingshan Lake wetland significantly affected plant diversity, while five ecological design methods in both Xixi Wetland and Tongjian Lake wetland significantly affected plant diversity; (4) among all the ecological design methods, four-ecological conservation measures, rain gardens, plant community structure, and the use of different plant species-clearly impact wetland plant diversity. To ensure the protection, differential utilization, and sustainable development of urban wetlands in the context of urbanization, managers and designers should carefully select appropriate ecological design methods based on the specific characteristics of each urban wetland.