Analysis On The Ecological Benefits Of Street Trees In West Lake Scenic Spot Based On I-Tree Model In Hangzhou

Based on the field investigation,this paper uses the i-Tree V5.0 model to analyze and evaluate the resource structure,ecological benefit and cost of 4417 roadside trees in nine roads in Hangzhou West Lake scenic area.Aiming at exploring the analyzing the interaction between the resource structure of trees and the application of i-Tree model to evaluate the ecological benefits of domestic street trees.The research results provide theoretical basis for tree selection and planting planning of urban street trees.The main findings are as follows:1?A total of 4417 road trees were surveyed,belonging to 12 families,12 genera,12 species.The total number of tree species of Platanus acerifolia,Liquidamba formosana and Sapindus mukurossi accounted for 77.9% of the total survey trees.The DBH range distribution of street trees was that DBH<15.2cm accounted for 3.31% of the total level,DBH 15.2-45.7cm 65.49%,DBH 45.7-76.2cm 12.84%,DBH> 76.2cm 2.04%.The growth type of trees is deciduous tree species accounted for 87.95% of the total,evergreen trees accounted for 12.05% of the total;Broad leaf species accounted for 92.55% of the total,coniferous species accounted for 7.45% of the total.In RPI(relative performance index)>1 species are total of 8 species of metasequoia of Platanus acerifolia,Liquidamba formosana,Cinnamomum camphora,Salix babylonica,Celtis sinensis,Pterocarya stenoptera,Acer buergerianum and Metasequoia glyptostroboides.The canopy covers an area of 40 hm2.IV(important value)and RV(replacement value)analysis results for Platanus acerifolia that maximum IV value was 63.47%,the RV of 4417 trees were 128832926 yuan.2?The ecological benefits of street trees in 2017 was evaluated by using the i-Tree model to evaluate the ecological benefits trees in nine roads were 6737382.75 yuan,and the total cost was 1548328.45 yuan.The ratio of benefit to cost is 4.35.The value of energy saving is 588732.79 yuan,the value of fixing carbon and carbon dioxide is 1037984.15 yuan,the value of air quality is 31456.94 yuan,the value of rainwater is 706755.54 yuan,the aesthetic value and other value is 4372453.33 yuan.The total value of ecological benefits of Platanus acerifolia was highest in all species that accounting for 66.10% of the total value of ecological benefits.The average weighted value per of Platanus acerifolia was 2313.81 yuan/ Strain,and it's value was highest.In terms of the total value of ecological benefits of the road,Nanshan Road,Beishan Road and Yanggongdi contribute the most to the total annual benefits,accounting for 64% og the annual benefits.The total benefits of Nanshan Road was the largest,accounting for 26.3% of the total annual benefits of the road,and the lowest annual benefits of the road was the Baidi.