Study On The Spatial Distribution Characteristics Of Tree Roots And Their Influencing Factors Based On Tree Radar

Thick roots of trees,as an important part of the root system,play an important role in the transportation of water,nutrients,and anchoring plants.The distribution of coarse roots in the soil space determines the spatial range in which trees can obtain water and nutrients.A strong and developed root system is the basis for the vigorous growth of tree branches.There is a large spatial heterogeneity in the distribution of thick roots of trees in soil space.Pinus koraiensis,Larix gmelini,Picea koraiensis and Pinus sylvestris are important dominant and precious tree species in Northeast China,and have high ecological and economic value.Therefore,this paper takes Pinus koraiensis,Larix gmelini,Picea koraiensis and Pinus sylvestris as research objects.This paper studies the spatial distribution of the thick roots of trees and analyzes the distribution characteristics of tree thick roots,tree factors,soil physical and chemical characteristics,and the decay of the trunk.The relationship between them can provide theoretical and data support for the good growth of tree roots.The main research contents and research methods of this paper include:(1)Study on the distribution rules of the thick roots of four tree species(Pinus koraiensis,Larix gmelini,Picea koraiensis and Pinus sylvestris).The tree root system was used to detect the root system of trees,and the distribution characteristics of the thick roots of four tree species in soil were investigated through field experiments and data analysis.(2)Study on the relationship between the distribution of tree roots and tree factors and soil physical and chemical properties.The tree height,DBH,crown width,and physical and chemical properties of soil were measured.Correlation analysis and stepwise regression analysis were used to study the relationship between them and the distribution characteristics of tree roots.(3)Study on the relationship between the distribution of tree coarse roots and trunk decay.Impedance meter and growth cone drilled core method were used to detect the decay of the experimental tree trunk,quantitatively characterize the degree of decay,and correlation between regression analysis and regression analysis was used to explore the relationship between the degree of trunk decay and the distribution of tree roots.Research indicates:(1)The spatial distribution of coarse roots of four tree species(Pinus koraiensis,Larix gmelini,Picea koraiensis and Pinus sylvestris)in space is generally expressed as follows:as the distance from the trunk and the soil depth increase,the thick roots of the tree The number is gradually decreasing.The thick roots of the four tree species showed a shallow distribution trend.About 81.17%of the thick roots of the trees were distributed in the depth range of 0?40 cm.(2)The number of thick roots of larch and Korean pine trees in the horizontal and vertical directions showed a decreasing trend with increasing distance from the trunk and soil depth.More than 80%of the thick roots of Larix gmelini and Pinus koraiensis are distributed in the range of 0-40cm soil layer.The distribution of the number of thick roots of Picea koraiensis and Pinus sylvestris trees in the horizontal direction showed a trend of decreasing gradually as the distance from the trunk increased.In the vertical direction,it increased first and then decreased as the soil depth increased.More than 80%of the thick roots of Picea koraiensis are distributed in 0?40cm soil layer,and more than 70%of the thick roots of Pinus sylvestris are distributed in 20?60cm soil layer.(3)The longitudinal distribution of the coarse root spatial distribution of 32 test samples of 4 tree species is approximately rectangular.According to the spatial distribution characteristics of the thick roots,the spatial distribution types of the crude roots of the test samples can be divided into shallow root types and deep Root system type.(4)The distribution density of tree thick roots has a significant positive correlation with tree height,DBH,and crown width;it has a significant positive correlation with soil water content,saturated water holding capacity,and capillary water holding capacity,and it has a significantly negative correlation with soil bulk density;There were significant positive correlations with organic matter content,total nitrogen content,total phosphorus content,and hydrolyzed nitrogen content.However,the density of tree roots distribution is not highly correlated with tree factor indicators and soil physical and chemical properties,indicating that there may be other factors affecting the distribution of tree roots in the soil besides tree factors and soil physical and chemical properties.The distribution of tree thick roots in the soil may be the result of a combination of various influencing factors.The characteristics of the tree itself and the physical and chemical properties of the soil cannot be the decisive factors affecting the distribution of tree thick roots.(5)When the degree of trunk decay is less than 21.83%,there is no significant correlation between the density of thick roots of trees and the degree of trunk decay and the average resistance value.The density of the distribution of thick roots of trees is not affected by trunk decay and tree material conditions.