植物群落结构和绿地类型对城市公园生态系统服务的影响及其耦合协调机制

The ecological functions of urban green spaces are diverse,so it is necessary to design and manage them scientifically to maximize ecological benefits.In this study,we assessed the differences in ecosystem services among various types of urban green spaces and their plant community structures to provide a reference for better park design.We conducted field experiments in 13 parks in Tianfu New District,Chengdu,China,and selected 28 vegetation sample sites representing five types of community structures and measured their cooling,humidification,particulate matter adsorption,negative ion supply,and noise reduction functions,respectively.We used multiple machine learning algorithms for weighted feature screening and developed a linear mixed-effects model,which considered community structure and green space type as random effects,to identify key factors.In addition,we developed a coupled coordination degree model to analyze the relationship between community structure,green space type,and ecosystem services.The results showed that proximity to water bodies,large tree canopies,high vegetation cover and high grass plants increased air humidity and decreased ambient temperature.Dense planting of low canopy trees and shrubs effectively reduced noise and particulate matter.Undulating slopes greatly influenced the distribution of negative oxygen ions.The coupled coordination showed that the composition of trees usually closely matched ecosystem services,while shrubs and herbs were less coordinated.Linear mixed effects modeling accurately identified influencing factors and explained how specific metrics regulate ecosystem services.The results suggest that optimizing plant community structure and blue-green ratio can enhance the ecological functions of urban green spaces.