Research On Health Evaluation And Ecological Benefits Of Campus Trees Based On I-Tree Eco Model

This study takes the trees on the Xuhui campus of Shanghai Institute of Technology as the research object,and conducts multiple on-site investigations on the trees on the campus.Establish a tree health evaluation system using a combination of principal component analysis and factor analysis,and use fuzzy comprehensive method to classify and evaluate the health of trees.Use the non-destructive tree testing instrument PICUS to detect the health of metasequoia trees in the campus,and analyze the relationship between the growth environment and health of metasequoia trees,in order to identify the sources of tree damage.Using the i-Tree Eco model to study the ecological value of campus trees,in order to evaluate their conservation value and propose the most effective management plan for tree conservation.(1)A total of 313 trees were surveyed in the campus,of which 212 trees met the requirements for ancient tree reserve resources,including cedar,camphor,cypress,metasequoia and weeping willow.Among them,the metasequoia species is one of the top ten rare trees endemic to China.The tree health evaluation model calculates a health evaluation score of2.34 points and a health index of 0.952.84.03% healthy,9.58% basic healthy,1.92% sub healthy,1.6% unhealthy,2.88% near death.(2)The evaluation and analysis of the health status of trees with different breast diameters showed that the trees with a breast diameter of 38.3-55.9cm had the highest number of trees.The diversity index of tree diameter at breast height in the campus is 1.32,with a relatively high index value.The order of each type of chest diameter according to the proportion of health value from high to low is: Grade I chest diameter>Grade V chest diameter>Grade VI chest diameter>Grade IV chest diameter>Grade III chest diameter>Grade II chest diameter.The order of health index from high to low is level I chest diameter>level IV chest diameter>level V chest diameter>level II chest diameter>level VI chest diameter>level III chest diameter.(3)The health index of different tree species,from high to low,is as follows: boxwood>camphor tree> privet> redbud> palm> cypress > metasequoia > cedar.The health index of metasequoia and cedar is lower than the average,while the health index of dragon cypress is at the same level as the median.The other five trees are all above the average.(4)The bulk density,moisture content,and porosity of the soil in the Metasequoia area of the playground are not within the standard.Metasequoia is one of the top ten rare trees unique to China.Using the PICUS stress wave tree fault image diagnostic instrument to detect Metasequoia trees,there were 70 healthy trees,and 5 trees had a health level below 95%,but there were no signs of damage or infection.RHL19 has 69% of the empty rot area at80 cm,while RHL63 has varying degrees of empty rot at 30 cm,80cm,and 120 cm.There is a highly significant negative correlation between health value and soil bulk density(P<0.01);There is a highly significant positive correlation between health value and soil moisture content,porosity,and conductivity(P<0.01).(5)The i-Tree Eco model calculates the ecological benefits of trees in Xuhui Campus.The total ecological benefit is approximately 26885.12 yuan/year.The tree species with better overall ecological benefits per year is camphor tree(94.88 yuan/plant),with a total benefit value of13127.98 yuan/year;The total benefit of metasequoia(63.95 yuan/plant)is 8951.25yuan/year.The tree species with poor annual ecological benefits are pomegranate(14.62yuan/plant)and privet(12.8 yuan/plant).The ecological benefits of trees are good,and the individual plant benefits are relatively high.(6)When establishing a tree maintenance plan,scientific restoration plans and establishing a long-term management mechanism for the campus should be utilized.Education and training should be provided to maintenance personnel to scientifically repair diseased trees.Reasonably plan the campus environment and adapt to local conditions and suitable trees.The protection of trees should be implemented among teachers and students,establishing a long-term health evaluation system,establishing tree evaluation records,and forming a long-term regulatory mechanism.