Investigation And Evaluation Of Health Status Of Heritage Trees Based In The Method Of Analytic Hierarchy Process And Hemispherical Photography In Jinping District,Shantou City

Heritage trees are not only excellent trees for time screening,but also the "living fossils" carrying the history.The value given by the years makes the heritage tree resources unique and non renewable.The combination of the ecological,landscape and cultural values makes the heritage trees the unique part of the ecological construction.However,due to the imbalance of economic development and the different attention of importance in different areas,the progress of protection for heritage trees is different.It is necessary and meaningful to help and promote the protection of heritage trees actively.This study is to evaluate and classify the indicators of trees whose age is more than one hundred years in Jinping District,Shantou,in order to provide basic data and analysis for the protection of heritage trees.After field investigation,there were 130 heritage trees in Jinping District of Shantou.The evaluation of the heritage trees is divided into four parts(whole,root,bole and crown)and 14 indexes(growth,inclination,root,root,root permeability bare root injury(visible),stem rot or empty,bark damage,trunk pests,partial crown,crown density,dry broken branches and leaves of hue and crown pests)of them are selected to evaluate and analyze the ancient health,through field investigation of the indicators of trees were measured,and fill in the corresponding per wood questionnaire and health questionnaire,and photographs.The data were statistically classified.The scores of each tree were calculated and analytic by AHP(Analytic Hierarchy Process).The scores of each tree were classified according to 3 grades:good(4.8-5),medium(4.5-4.7)and general(below 4.5).And with the hemisphericalphotography images,using Gap Light Analyzer tree canopy structure on each level of the canopy openness(Canopy Openness)?leaf area index(LAI)?transmitted direct gap light(Trans Dir)and transmitted diffuse gap light(Trans Dif)were measured and analyzed.The main results are as follows:(1)the overall situation is as follows: the health evaluation of heritage trees in Jinping District of Shantou city is in 4.1985-4.9794,the average score is 4.6391,and the overall heritage tree is in good condition.There were 23 heritage trees reach the good grade,accounting for 17.69% of the total.79 of the heritage trees reached the medium grade,accounting for 60.77% of the total,and 28 of the general grade heritage trees accounted for 21.54% of the total,(2)The canopy openness is between 10.51%-57.33% of the heritage trees,and the average is 21.47%,combine with the level of the health evaluation for the trees,the good grade(23.45%)> the medium grade(21.22%)> the general grade(20.55%).And positively correlated with the level,trend of trees health evaluation;The leaf area index(LAI)is between the 0.96-3.97,and the average is 2.44.The leaf area index of health evaluation grade is the good grade(2.36)< the medium grade(2.45)< the general grade(2.52).The grade of the health evaluation of the heritage trees changed with the leaf area index is negatively correlated;The transmitted direct gap light(Trans Dir)is between the 5.38%-47.24%,and the average is 17.99%.The transmitted direct gap light of health evaluation grade is the good grade(17.25%)< the medium grade(18.09%)< the general grade(18.31%).The grade of the health evaluation of the heritage trees changed with the transmitted direct gap light is negatively correlated.The transmitted diffuse gap light(Trans Dif)is between the8.07%-48.06%,and the average is 17.56%.The transmitted direct gap light of health evaluation grade is the good grade(17.43%)< the medium grade(17.51%)< the general grade(17.83%).The grade of the health evaluation of the heritage trees changed with the transmitted diffuse gap light is negatively correlated.