Investigation And Protection Of Ancient And Famous Trees Resources In Daxing District Of Beijing

The ancient and famous trees in Daxing district of Beijing were taken as the research object in this paper.Resource survey was conducted in the inspect of the species composition and quantity,age structure,distribution characteristics,health status and protection status of the ancient and famous trees,based on which,the main problems in the growth and protection of ancient and famous trees were discussed,and the causes of these problems were analyzed.Finally,suggestions of the corresponding protection measures were put forward.The aim of the research is to provide references for protection of ancient and famous trees and the urban ecological construction in Daxing district.The main results of the research were as follows:(1)The ancient and famous trees in Daxing district with a total of 128 trees,including 127 ancient trees and 1 famous tree,belong to 9 families,10 genera and 10 species.The largest number of genus was Cupressaceae,and the most species was Sabina chinensis(L.)Ant.,which was the local dominant species.The species and quantity of ancient and famous trees in this area were small,most of them were single families,single genera and single species,the species were relatively single.(2)The age of ancient trees in Daxing district is relatively small,ranging from 100 to 522 years,the age of most trees ranging from 200 to 299 years.Among them,there were 12 first-class ancient trees and 115 second-class ancient trees.The age of ancient trees shows a single peak curve,and the age structure was single.In the process of tree age from low to high,the number of ancient trees increases first and then decreases.(3)The ancient and famous trees are distributed in 13 towns and 29 places in Daxing district.The number of ancient and famous trees was extremely unevenly distributed in the all towns.The largest number of trees in all towns was distributed in 2 places of Xihongmen town,in which there were 97 ancient and famous trees,accounting for 75.78% of the total number.It was found that there was an ancient tree group with 96 trees only in one place of Xihongmen town and only few trees in other towns and no trees in Yinghai town.The number of ancient and famous trees was not evenly distributed in various growing places.The largest number of trees,105 trees in total,were distributed in park and greenbelt.(4)The overall health status of ancient and famous trees in Daxing district is good,which is due to corresponding protection measures for most trees.The proportion of ancient and famous trees in the status of healthy,sub-healthy or unhealthy was 73.44%,20.31%,6.25%,respectively.Dying trees were not found.However,26.56% of the trees was in the status of sub-healthy and unhealthy.It was demonstrated that there are still some defects in the protection of ancient and famous trees.(5)It was found that there were four factors that affected the health status of ancient and famous trees after investigation: Firstly,mechanical damage and rainwater infiltration caused 26 ancient and famous trees to be hollow in the stem of trees in the whole region,among which the number of Sophora japonica Linn.was the largest,accounting for 69.23%;Secondly,pests and diseases infestation or man-made destruction etc.resulted in the larger proportion of withered and broken branches of ancient and famous trees;Thirdly,the large proportion of pavement on the surface hindered the roots growth;Lastly,the lack of nutrients which affected the health status of ancient trees.(6)It was found that there are three problems in the protection of ancient and famous trees in Daxing district after investigation: First,the contradiction between trees growth space and land usage is gradually intensified;Second,the conservation measures are not professional enough;Third,the awareness of the whole society for ancient trees protection is weak.In view of the small total number,small age,uneven distribution and protection status of ancient and famous trees in Daxing district,incremental protection measures were put forward based on the existing resources of ancient and famous trees: First,urban landscape planning should be done well to deal with the contradiction between trees growth space and land usage;Second,media propaganda should be fully utilized to enhance the public’s awareness of ancient and famous trees protection;Third,follow-up resources of ancient and famous trees should be fully tapped.In view of the main problems existing in the sub-healthy and unhealthy ancient and famous trees in Daxing district,the corresponding protection technologies were put forward: The first was to repair the tree cavity and improve the immunity;The second was to reduce the surface pavement area and improve soil properties;The third was to strengthen the daily maintenance management and prevent diseases and insect pests.