Investigation And Evaluation Of Health Status Of Ancient And Famous Trees In CongHua District,Guangzhou City

Ancient famous trees have ecological values that affect the hydrological conditions of the ecosystem,carbon storage,nutrient cycling and microclimate,and provide habitat for a large number of plant and animal species.They are considered to be historical and cultural symbols,used for religious and sacrifice activities,and have important ecological and cultural values.However,due to climate change and increased human activities,the survival of ancient famous trees is facing severe challenges,especially in large cities with compact populations.Considering the value and ecological function of ancient trees,protecting them has a certain scientific and economic value,and helps to combine the welfare of trees with the ecological and cultural environment of the city to seek a sustainable smart city.The urban forest of Guangzhou is one of the best forests in China,with a lot of ancient trees.However,due to the intensity and prevalence of high-density urbanization,urban forests in Guangzhou are degrading.Therefore,this study focused on the ancient and famous trees in Conghua District,Guangzhou.The data of basic characteristics such as the type,regional distribution,and age of ancient and famous trees in Conghua District were investigated.Then,through AHP-fuzzy comprehensive evaluation method,a set of index system applicable to the health evaluation of ancient and famous trees was constructed,and the health status of existing ancient and famous trees in Conghua District of Guangzhou City was analyzed.These findings can provide a scientific basis for the protection and management of ancient trees in Guangzhou and other cities in southern China,and will help us better protect these ancient trees and valuable trees in the future urbanization process.The specific research results are as follows:(1)There are 497 ancient trees and 3 famous trees in Conghua District,belonging to 22 families,28 genera and 33 species,including 10 second-class ancient trees and 487 thirdclass ancient trees.Among them,Moraceae and Caesalpiniaceae belong to the largest number of ancient and famous trees,with 137 and 126,respectively,accounting for 53% of the total number of ancient and famous trees in the region.The oldest tree is the 420-year-old Bischofia javanica,followed by the 370-year-old Ficus microcarpa and rough-leaved trees and the 350-year-old Aphananthe aspera.There are 17 ancient and famous trees with a bust of over 800 cm,including 12 Ficus microcarpa,4 Ficus concinna and 1 Bischofia javanica,accounting for 70.59%,23.53%,and 5.88% respectively.(2)After field investigation and statistics,the number of parasitic or epiphytic trees of ancient and famous trees was 60,accounting for 12%;the number of plants with pests and diseases was 89,accounting for 17.9%.The main types of diseases and insect pests include basidiomycetes,such as phellinuspini;insects such as leafhoppers,scale insects and beetles.There are 82 ancient trees with termite activity traces in ancient trees,accounting for 16.4%,and the damage is more serious.In addition,the trunks of ancient trees are still severe.Among the 497 ancient trees,a total of 126 plants had different degrees of tree decay or hollowness,accounting for 25.3%.(3)In this study,the AHP-fuzzy comprehensive evaluation method was used to establish the health evaluation body of ancient and famous trees from three aspects: the whole tree,the crown and the trunk.Then evaluate the health status of ancient and famous trees in Conghua District,Guangzhou.Among the 497 ancient and 3 famous trees in Conghua District,90 belong to the grade “Excellent”(5-4.5 points),accounting for 18% of the total,220 belong to the second-class “Good”(4.5-4 points),accounting for 38.6% of the total,160 belong to the third-level “Average”(4-3.5 points),accounting for 8.2% of the total,and 30 belong to the fourth grade “Poor”(3.5-3 points),accounting for 1.8% of the total.The average health evaluation of 500 ancient and famous trees in Conghua District of Guangzhou is 4.119,which belongs to the second-class “good” range.The overall health of ancient and famous trees in Conghua District of Guangzhou is relatively good.