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

Urban wetlands constitute a pivotal element within urban ecosystems. The implementation of ecologically sound wetland design methods can foster their biodiversity while augmenting overall ecosystem services. This study investigated three urban wetlands—Xixi, Tongjian Lake, and Qingshan Lake wetlands as the core, fringe, and suburban areas, respectively, of Hangzhou in Zhejiang Province, China. The plant species composition of these wetlands was quantified and 33 ecological design methods were accessed across the values of water quality protection, shoreline maintenance, ecological facilities, and plant diversity. Employing structural equation modeling, design methods significantly influencing plant diversity were identified. Key findings reveal: (1) variances in plant species and design methods occurred across wetlands, with the Xixi Wetland in the urban core displaying higher biodiversity; (2) four design methods—ecological conservation measures, rain gardens, complex plant community structure, and increased hydrophytic species populations—significantly impacted wetland plant diversity; (3) divergent pathways of design methods can be used to improve plant diversity in different urban wetlands; and (4) rational ecological design enhances plant diversity but may have time-limited effects, necessitating ongoing management to be effective. It is crucial that land managers ensure urban wetland protection occurs amidst urbanization using carefully tailored land use planning and management while considering wetland functions and characteristics. This research underscores the importance of employing ecological design methods strategically for sustaining and maximizing the benefits of ecosystem services that urban wetlands can provide.