基于i-Tree模型的行道树生态系统服务价值

Valuation of Street Tree Ecosystem Services Based on i-Tree Model

行道树作为街道绿化系统的骨架,支撑着城市生态系统服务功能的正常运转。以武汉市临江大道中段为例,基于i-Tree构建行道树生态系统服务的综合评议模型,通过以货币值作为统一衡量标准分析演算研究地27种常见行道树及街道整体生态系统服务价值,旨在为行道树树种选择优化,以及街道景观与生态环境的提升提供参考。结果表明:1)在街道的植景搭配中,整体生态系统服务价值排序为:美学价值>能源节省价值>雨水截留价值>空气净化价值>生态固碳价值。2)研究地全部行道树年生态系统服务价值约131.8万元,平均1 km行道树年生态系统服务价值可达28.65万元,单株行道树年平均生态系统服务价值可达307.23元。3)行道树具有可观的生态系统服务价值,同时也存在明显种间差异,其中能源节省、美学价值和雨水截留价值在演算树种中价值量较高,空气净化和生态固碳价值量较低。因此,在街道行道树配置过程中,应将能源节省、美学价值和雨水截留价值作为首要参考因素,再结合街道属性综合考虑树种选择与应用,以构建功能全面的城市行道树生态系统服务结构,提高行道树整体的生态系统服务价值。

As the skeleton of street greening framework,street trees support the operation of urban ecosystem services.Taking the middle section of Linjiang Avenue in Wuhan as an example,the paper constructs a comprehensive evaluation model for street tree ecosystem services based on i-Tree,and analyzes the ecosystem service value of both 27 common street trees and streets in the study area using monetary value as a unified measurement standard,aiming to provide a reference for the selection and optimization of street tree species and for the improvement of street landscape and ecological environment.The results show that:1)In the plant-landscape configuration of streets,the ecosystem service values are ranked as aesthetic value>energy saving value>rainwater interception value>air purification value>ecological carbon sequestration value;2)The annual ecosystem services of street trees in the study area are valued at about 1.32 million RMB,the ecosystem services of street trees per kilometer annually create a value at 290000 RMB,and the average annual ecosystem service value of one individual street tree is 305.4 RMB;and 3)Street trees have considerable ecosystem service value,but there are also obvious interspecific differences,among which energy saving value,aesthetic value and rainwater interception value are higher with the tree species for calculation,and the value of air purification and ecological carbon sequestration is lower.Therefore,it is suggested that energy saving,aesthetic value and rainwater interception value should be taken as the primary factors for reference in the process of street tree configuration,and the selection and application of tree species should be comprehensively considered in combination with street attributes,so as to construct a comprehensive ecosystem service structure of urban street tree and improve the comprehensive ecosystem service value of street trees.