Response Of The Tree Ring To The Environmental Change Based On The Resistograph Data

In recent years,it makes a rare report on the study of the ring and environmental changes in urban landscape tree species,in view of the lack of technical means,the difficulty of access to basic data and other reasons.In this study,Platanus acerifolia which is a representative tree in Nanjing is selected,using the Resistograph device to drill the tree ring data of the Platanus acerifolia at ground diameter from the east and west,north and south,respectively.We try to use the foreign advanced instrument on the Platanus acerifolia street tree for non-destructive measurement,geting ring width,ring density,earlywood density,latewood density and other ring index.The radial growth model of Platanus orientalis was established,relationships of the relative density index of wood to the monthly mean temperature?monthly average maximum temperature,monthly mean temperature,monthly mean minimum temperature?and monthly precipitation were analyzed,and the relationship between the relative density index of the wood and the climatic factors were simulated by multiple stepwise regression analysis and principal component regression analysis,in order to reveal the response of the tree ring to the environmement change.The main results were as follows:?1?The group A ring width grow model of Platanus orientalis on street's roadside was y=5.111*t^1.024;The group B ring width grow model of Platanus orientalis on street's roadside was y=0.0089t²+2.751t+2.391.?2?We calculated the correlation coefficients between the temperature of the three base point?the average monthly maximum temperature,the monthly mean temperature,the monthly mean minimum temperature?and the monthly precipitation,respectively.The results indicated that the correlations between the variation of tree ring density of the Platanus acerifolia street tree and the temperature and precipitation was inconsistent in Nanjing.The density of the tree was not significantly related to the precipitation of the various months,and the precipitation in October was a certain extent significantly related to the relative density index of wood?P<0.05?;the correlation coefficients between the monthly mean temperature in May and all the tree ring density of Platanus acerifolia was the largest,indicating great influence.The effect of moisture on the radial growth of Platanus orientalis was less than that of temperature,the temperature condition was the main limiting factor for the growth of Platanus orientalis and the temperature change was very complicated.?3?Modeling the relationship between the tree ring of Platanus orientalis and the climatic factors by the method of multiple stepwise regression analysis,it was known that the climate information of earlywood density was more than that of latewood density.In the index of several tree ring density,the young and half matured Platanus acerifolia were mainly affected by the average temperature in October last year,and the mature Platanus acerifolia were mainly affected by the average temperature in February.?4?In this paper,the effects of nine climatic indexes,such as the average temperature?maximum temperature,minimum temperature,mean temperature?and annual precipitation on the tree-tree density of Platanus acerifolia in 1982 2013 were selected by principal component analysis and regression analysis.The results show that the three principal contributors with cumulative contribution rate of 90.46% are extracted,which contains the information of most of the original variables,indicating that these indexes can be used for principal component analysis.In addition,from the regression analysis results that the temperature is the most influential indicators,rainfall and humidity less than the temperature,which may be related to the abundant rainfall in Nanjing.?5?Resistograph equipment can be a good measure of the relative density of wood,the hole diameter on the tree trunk of Platanus orientalis was only 1.5mm,less than the traditional growth cone destructive,effective protection of the old trees.