Street Trees in a Chinese Forest City: Structure, Benefits and Costs

Xueyan Wang,Wei Chen,Shuai Yu,Chunping Miao,Jing Yao,Xingyuan He

doi:10.3390/su10030674

Abstract

Street trees provide critical ecosystem services and economic benefits that are often disregarded, due to their unknown monetary value. This study analyzed the structural characteristics of Dalian’s street trees and estimated the monetary value of structural and functional benefits by i-Tree Streets. Dalian’s street trees encompassed 28 species and were dominated by Ginkgo biloba, Platanus acerifolia and Sophora japonica, comprising 64.1% of a total of 57,699 trees. The age structure of street trees was distributed somewhat unevenly, with 18% young trees, 56% maturing trees, 25% mature trees and 1% old trees. These trees provide annual functional benefits valued at US$4.9 million and delivered a benefit-cost ratio of 3.2:1. The largest values associated with energy savings and property value were $1.7 million ($29/tree) and $1.5 million ($25/tree), respectively. The net carbon reduction benefits were valued at $935,205 ($16/tree). Smaller benefits resulted from air quality improvement ($381,088 or $7/tree) and stormwater runoff ($459,457 or $8/tree). The structural benefits were valued at $130 million, with the value of $4.5 million for carbon storage. These findings suggested that the benefits produced by street trees were worth the management costs. Our results provide a thorough understanding of the benefits produced by street trees to policy-makers and managers, and help them make informed policies to maximize and sustain the flow of benefits.

Highlights

Urbanization is a spreading phenomenon across the world and promotes economic development and poverty reduction [1]
Street trees, as part of the urban forest, play a vital role as they provide ecosystem services that improve the quality of the environment and life
A diversity of street tree species is important to enhance the stability of street trees and protect street trees against the possibility of catastrophic losses [61]

Summary

Introduction

Urbanization is a spreading phenomenon across the world and promotes economic development and poverty reduction [1]. The deteriorating environment in cities has generated the urgent need for a comprehensive study of urban forests as they can alleviate environmental deterioration and improve quality of life [5,6,7,8]. Street trees (trees growing in the urban street), as part of the urban forest, play a vital role as they provide ecosystem services that improve the quality of the environment and life. Street trees can conserve energy, sequestrate CO2, remove air pollutants, and reduce stormwater runoff [9,10,11,12,13]. Street trees can increase business income and real estate values by increasing community attractiveness and recreational opportunities [14]

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Discussion

Conclusion