Effect Of Different Tree Measuring Factors On Ring Resistance Based On Resistograph Data

This paper takes Dongtai Forest Farm in Dongtai City,Jiangsu Province as the research area,and uses a Resistograph that can measure the internal resistance of trees to provide a non-destructive measurement method for tree age acquisition.According to the change of resistance value,we study different tree species,different planting densities and different The law of tree growth under age.In the two vertical directions of the trees and the north and south directions,the Resistograph is used to collect data on the DBH of the trunk,and the growth cone is used to obtain the age data of the trees.The feasibility of measuring the age of trees by Resistograph was studied.The relationship between the average resistance value of trees and different tree species,different planting density and different ages was analyzed.The main findings include the following:（1）A total of 60 plot data were obtained through field surveys,and the Resistograph data was validly sampled at 56 plots.According to age and planting density,35 poplars had 10 groups of 40 plots,351 poplar,I-69 poplar,There are 4 plots of each of Metasequoia and Ginkgo.Using the DECOM^TM software to extract the age of the acquired Resistograph data,compared with the actual age obtained by the growth cone,although the accuracy is not high,the data obtained by the growth cone is high,but the age of the tree can be obtained effectively and non-destructively using the Resistograph.And the ages obtained from both directions can be cross-validated in the TSAP-Win software to improve the accuracy of the age of the Resistograph.（2）When the Resistograph extracts the age of the species of Metasequoia,there is basically no large error,and the accuracy is relatively high.The accuracy of the ages of 35 Poplar,69Poplar and 351 Poplar is second,and the result obtained by 35 Poplar is accurate.The sex is higher,but when measuring the ginkgo tree species with the Resistograph,the extracted age results show more errors,and the accuracy is lower than other tree species.Whether it can be used as a method to measure the age of the ginkgo tree species needs further confirmation.（3）Two Resistograph data from each other are obtained from each tree.After preprocessing by DECOM^TM software,the maximum resistance value and minimum resistance value in each direction can be extracted in Excel software.And the average resistance value.Using the paired T-test to analyze the average resistance values in both directions,the results show that there is no significant difference in the average resistance values in the two directions,but in order to obtain a more accurate average resistance value of the annual rings,two directions can be obtained.The upper resistance value is summed and the average value is taken as the annual resistance value of the individual trees.（4）By analyzing the variance of the annual mean of different tree species,it is found that the average resistance value of different tree species is significantly different.The average annual resistance value of poplar species is significantly higher than that of Metasequoia and Ginkgo biloba,and the average resistance between them The specific relationship of the values is 35Poplar>I-69 Poplar>351 Poplar>Ginkgo>Metasequoia.And the average resistance value of poplar tree species from outside to inside is higher than that of Metasequoia.（5）Under different planting densities,the average resistance values of 35-year-old,15-year-old and 18-year-old 35 poplar were subjected to t-test and analysis of variance,respectively.The results showed that the Institute set different planting densities to the average of35 poplars.The resistance value has no significant effect and has no effect on the change trend of the resistance within the individual trees.This is also related to the age of the selected poplar.When the age of the poplar has not yet reached a certain stage,the planting density will not affect its The change in resistance value.（6）Under the condition of not considering the influence of planting density on the average resistance value of annual rings,the effects of different ages on the average resistance value of 35Poplar rings were analyzed separately.The results of variance analysis showed that the average resistance value of 35 Poplar was significant at different ages.Differences,further multiple comparisons found that the differences between the 3-year,6-year and 12-year-old were not significant.In addition,there was a significant difference in the average resistance values extracted between any other two age groups.Regression analysis was performed on the different ages of 35 Poplar and the extracted average resistance values,and the regression equation was obtained as y=-0.0167x³+0.7358x²-7.53x+164.15,and R²=0.6955.（7）During the long development of 35 Poplar,the fastest growing stage is between 6 and 9years.According to the growth law found,when planting and planting,it is possible to focus on this growth stage.Growing faster,more tending measures should be given manually,increasing fertilization and irrigation,and strengthening thinning management.