Study On The Present Situation And Influencing Factors Of Ancient And Famous Trees In The Central District Of Zhengzhou

As a living fossil closely related to nature and social environment,ancient and famous trees have important ecological value of historical and cultural research.With the continuous development of urban construction,Zhengzhou City,as one of the Central Plains urban agglomerations,has also suffered some damage to ancient and famous trees in its central district.Therefore,how to better protect and manage ancient and famous tree resources in urban development and construction is an urgent problem to be solved.In this study,the central district of Zhengzhou was taken as the research area to investigate the current situation of ancient and famous trees in the central district,and the influencing factors of the current situation and growth status of ancient and famous trees in the central district were explored through Arc GIS,Moran’s index,geographical detector,correlation analysis,principal component analysis and other methods.On this basis,combined with the existing problems of ancient and famous trees in the central district,relevant suggestions were put forward for the subsequent protection and management of ancient and famous trees in the central district of Zhengzhou,which had certain guiding significance for the further protection of ancient and famous trees in Zhengzhou City.It also has reference significance for the protection of ancient and famous trees and surrounding space planning in other areas with high urbanization rate and strong urban construction intensity.The main conclusions of this paper are as follows:(1)There are 307 anceint and famous trees in the central district of Zhengzhou,belonging to 27 genera and 28 species in 17 families,of which the legume family constitutes the core of the resource structure of ancient and famous trees in the central district of Zhengzhou;the native plants occupy the main advantage in terms of species origin,with the least foreign introduced plants;the central district of ancient and famous tree resources in the geographical zone to the north temperate distribution type occupy an absolute advantage,but also has a clear north subtropical to temperate transition characteristics;there is one national protected plant,one provincial protected plant,two plants listed in the Red Book of Chinese Plants,and one endangered plant in the central district;in terms of administrative division,there are two central clusters and multiple clusters;in terms of administrative division,there are mainly two central clusters and multiple groups,among which Huizi District is the richest in ancient and famous tree resources and Zhengdong New District is slightly poor in ancient and famous tree resources.(2)The growth of ancient and famous trees in the central district of Zhengzhou is good on the whole,with only a few trees in poor growth;the living type is mainly deciduous broadleaved trees in terms of the number of individuals and species;the survival environment of ancient and famous trees in the central district as a whole is in a good state,and there are fewer ancient and famous trees in poor survival environment;the age of trees is mainly concentrated in the lower age stage,with a stable pyramidal structure,which also reflects the rich reserve resources and stable age structure of ancient trees in the central district of Zhengzhou;the diameter at breast height,crown width and height of ancien and famous trees in the central district are normally distributed,with the value of famous trees generally lower due to the limitation of growth years.(3)The number and species of ancient and famous trees in the central district of Zhengzhou are mainly concentrated in the lower elevation range from 70 m to 110 m,the number and species of ancient and famous trees below 110 m increase with the elevation,and vice versa when the altitude exceeds 110m;on the slope,the number and species of ancient and famous trees below 5°(below the gentle slope)increase with the slope,and vice versa;on the different slopes,the number and species of ancient and famous trees in the central district have a small difference in distribution.The number and species distribution of ancient and famous trees in the central district are less different in different slopes;in the distribution of ancient and famous tree land types,the number and species of ancient and famous trees are more in areas with good ecological environment,and slightly less in areas with poor ecological environment;the number and species of ancient and famous trees in the central district are significantly negatively correlated with population density,distance of river systems and road density;in the overall analysis,it can be seen that the influence of various factors on the current distribution of ancient and famous tree resources can be ranked as follows: distance of river system > land type > population density > road density > elevation >slope > slope direction,with the most significant influence of river system distance and land type.(4)In the case of different ages,the age and diameter at breast height of Grade I ancient trees are mainly influenced by the average annual precipitation,and the height and crown width are mainly influenced by the altitude;the age of Grade II ancient trees are mainly influenced by the average annual PM2.5 concentration,the height is mainly influenced by the average annual solar radiation,the diameter at breast height is mainly influenced by the average annual precipitation,and the crown width is mainly influenced by the survival environment score;the age of Grade III ancient trees are mainly influenced by the altitude,the height is mainly influenced by the average water vapor,diameter at breast height are mainly affected by the average annual precipitation,and the crown width is mainly affected by the soil p H;the age,height and diameter at breast height of famous trees are mainly affected by the average annual temperature,and the crown width is mainly affected by the average water vapor;in the case of different land types,the age of ancient and famous trees on green land is mainly affected by the average annual water vapor,the height is mainly affected by the average annual solar radiation,the diameter at breast height is mainly affected by the soil p H,and the crown width is mainly affected by the average annual solar radiation.The age and diameter at breast height of ancient and famous trees on residential land are mainly influenced by the average annual precipitation,tree height is mainly influenced by the average annual solar radiation,and crown width is mainly influenced by the average annual PM2.5concentration;the age,diameter at breast height and crown width of ancient and famous trees on transportation land are mainly influenced by the average annual precipitation,and tree height is mainly influenced by the average annual water vapor.The age of ancient and famous trees in public management and service sites is mainly influenced by the average annual solar radiation,tree height is mainly influenced by the ecological environment score,diameter at breast height and crown width are mainly influenced by the average annual temperature;the age of ancient and famous trees in commercial service sites is mainly influenced by the average annual precipitation,tree height is mainly influenced by the average annual solar radiation,diameter at breast height is mainly influenced by the degree of altitude,and crown width is mainly influenced by the average annual water vapor.In the overall analysis,it can be seen that the influence degree of each factor on the growth status of ancient and famous trees can be ranked as follows: annual average water vapor > annual average solar radiation >annual average PM2.5 concentration > annual average precipitation > altitude > soil p H >annual average temperature > growth environment score.(5)Although most of the ancient and famous trees in the central district of Zhengzhou are relatively well protected,there are still some of them facing various threats to their survival,a slight lack of protection and publicity work by the relevant departments,insufficient special funds for protection and lack of professional conservation teams,etc.Based on these problems and combined with the previous analysis of this paper,we put forward relevant protection suggestions from 3 aspects: production planning and construction,management of relevant units and rejuvenation and protection techniques.