Evaluation Of Ecosystem Services And Design Of A Typical Application Case In A Mountain City

Long-term urbanization has brought many negative impacts to the urban environment,such as air pollution,soil erosion and reduction of landscape open space.Urban green space helps to mitigate these impacts,improve the quality of life of urban residents and maintain the balance of the urban ecosystem.A healthy and stable ecosystem is an inexhaustible driving force for sustainable urban development,and the assessment of ecosystem service value and its functional rating is an important method to evaluate the quality of ecosystems.This study takes full account of the specific situation of green areas in the central city of Zunyi,including aspects such as topography and socioeconomic conditions,as well as data accessibility.Based on the basic characteristics of mountain cities and with reference to many research results,a classification system for ecosystem services in mountain cities was constructed.The functional value approach is used to try to study the mountainous urban ecosystem services and their value assessment,and attempt to apply it to urban green space planning,design and construction.For four different types of ecosystem service functions,suitable monetary value assessment methods were selected for evaluation and calculation to assess nine indicators of greenland ecosystems in the central city of Zunyi City,Guizhou Province in 2021,including eight regulating service values as well as one cultural service value,to deeply analyze their ecosystem service value quantity results.Then the ecological service value assessment results were standardized by the full-arrangement polygon graphical method and classified into four levels according to the strength of their functions.Finally,based on the data analysis and rank distribution,this study proposes targeted recommendations to improve the urban green space landscape.The study shows that:(1)The assessment results of nine ecosystem service values in the central city of Zunyi are as follows: cultural service value > climate regulation value > soil conservation value > water connotation value >carbon sequestration and oxygen release value > noise reduction value >air purification value > flood storage value > water purification value.The contribution of cultural services is the most prominent,accounting for89.20% of the total value of ecosystem services in the central city of Zunyi;the contribution of three indicators of the value of climate regulation,soil conservation and water conservation services in regulating services is significant,and the sum of the three values accounts for94.17% of the total value of regulating services.The amount of flood storage and water purification value is relatively low.Therefore,the indicators with low functional amount need to be focused on and improved in the subsequent urban planning,design and construction.(2)According to the assessment results of different ecosystem service types,among the four types of ecosystems: trees,shrubs,grasslands and wetlands,trees and shrubs ecosystems provide great contributions to the ecological environment of Zunyi City and should be protected in the subsequent urban development and construction,while relatively wetlands and grasslands ecosystems need to be improved.According to the assessment results of different administrative divisions,the sum of the value of Honghuagang District and Huichuan District accounts for85.00% of the total value of ecosystem services,indicating that the economic value of ecosystem services provided by areas closer to urban centers is more significant.(3)The current problems of urban green space planning in the central city of Zunyi are mainly reflected in the serious influence of industrialization in some centers and clusters,the frequent development and construction activities on the mountainous city,the uneven distribution of various types of green space,and the strong heat island effect in some centers and clusters.Therefore,for the primary ecological protection zone and secondary ecological improvement zone need to carry out protection and maintenance,and improve the ecological environment of the tertiary ecological control zone and the quaternary ecological restoration zone by taking measures such as increasing the green space rate,accelerating the construction of park green space,and improving rainwater storage and purification water quality in various areas of Zunyi City,so that the urban green space ecosystem can develop in a long-term and stable manner.(4)The proposed landscape planning and design strategies based on the results of the ecosystem service value assessment and the full-arrangement polygon mapping method were concretely implemented on the sites of the three-level ecological control zone and four-level ecological restoration zone in the central city of Zunyi.Taking an area in a four-level ecological restoration area as a case study,we insist on the principle of "people-oriented" urban green space design,and fully consider the ecological environment of the site,fully consider the local plant species,and reasonably use trees,shrubs and vines to compound the landscape in all seasons.The detailed design aims to improve the poorly characterized soil conservation,air purification,noise reduction and cultural service value indicators within the site.