Spatiotemporal Evolution and Trade-offs among Ecosystem Services in Tianjin Wetland Nature Reserves Based on the InVEST Model

Ang Yue^1,2Xueer Guo³Haiying Gong³Xinhui Ji³Yatao Zhang^4*Wanfeng Wang^5*

• ¹School of Environmental Science and Engineering, Tianjin University, Tianjin, China
• ²Tianjin Eco-Environmental Monitoring Center, Tianjin, China
• ³Tianjin Normal University, Tianjin, China
• ⁴Tianjin Environmental Emergency and Accident Investigation Center, Tianjin, China
• ⁵Tianjin Natural Resources Ecological Restoration and Remediation Center, Tianjin, China

Wetland ecosystem nature reserves have ecological protection and cultural and educational functions; thus, scientific assessments of their ecosystem services and associated interactions are required. This study evaluated the ecosystem services water resource supply, soil conservation, carbon fixation and oxygen release, and habitat quality in four wetland reserves in Tianjin from 2000 to 2020 using the Integrated Valuation of Ecosystem Services and Trade (InVEST) model and explored their temporal and spatial evolution laws. The ecosystem trade-off synergy model was used to analyze the relationships between ecosystem services. The results showed that 1) wetland nature reserve ecological service functions differed significantly. Habitat quality improved, soil conservation declined slowly, and carbon storage decreased from 7.61 t/hm2 in 2000 to 5.23 t/hm2 in 2015 and rebounded thereafter. 2) The ecological service functions of the core area and buffer zone in the protected area were generally higher than those in the experimental area, with 1 t/hm² higher carbon storage in the core area and 0.1 t/hm2 higher soil retention. 3) A complex trade-off and synergy relationship occurred between ecosystem service functions. Soil conservation showed greater synergy with habitat quality and carbon storage, while carbon storage showed higher trade-offs with habitat quality and water production.