Growth Analysis And Simulation Of Platycladus Orientalis,Pinus Densiflora,Robinia Pseudoacacia Under Different Site Conditions In Mountainous Area In The Middle Of Shandong

Forest ecosystem dominated in the global climate change,is the important guarantee of the earth's ecological balance.Accurate monitoring and evaluation,the grasp and management of forest ecological system has important significance.Plantation growth analysis and simulation,which can be timely grasp of dynamic change,for plantation management and provides a scientific and reasonable theoretical basis for production practice..Taking Platycladus orientalis,Pinus densiflora,Robinia pseudoacacia as the research object,collecting data through sample plot and analytic trees on six types site condition in mountainous area in the middle of Shandong province,using variance analysis and multiple comparisonusing with the control variable method,studying the variation of different tree species growth under different site conditions.The results show that the average growth of height,DBH and volume of Robinia pseudoacacia's were higher than that of Pinus densiflora and Platycladus orientalis,and Pinus densiflora' s growth was higher than that of Platycladus orientalis;Platycladus orientalis grow best on sunny slope and thick soil and worst in shady slope and thin soil;The growth of Pinus densiflora in sunny slope were higher than that in the shady slope;Robinia pseudoacacia grow best in sunny slope and thick soil.The growth of the three trees species is good in this area;Robinia pseudoacacia was better than that of Pinus densiflora,Pinus densiflora was better than that of Platycladus orientalis.The results can provide reference for tree species selection on different site condition in Shandong province.At the same time,this paper takes in Platycladus orientalis,Pinus densiflora,Robinia pseudoacacia as the research object,under different site conditions will be fixed sample survey data of 589 and 142 strains of analytical data in accordance with the ratio of 5:1 is divided into modeling data and test data,and based on the predecessors' theory basis of summarizing the experience equation of screening single growth model,by multiple stepwise regression and nonlinear regression to build Platycladus orientalis,Pinus densiflora,Robinia pseudoacacia plantation has nothing to do with the distance of single chest high basal area growth model,tree height curve model,volume growth model and low loss rate model,the results show that all the parameters of the model in variable by T test and F test,P<0.05,the multiple correlation coefficient R2 were above 0.7,and the approximate normal distribution and residual distribution through the model test,this research about single growth model in three tree species and low loss rate of the model fitting effect is ideal.This study to overcome the past research of small amount of data and geographical limitations,lack of typical problems,for the first time in Platycladus orientalis,Pinus densiflora,Robinia pseudoacacia plantation system analysis under different site,successful build in Platycladus orientalis,Pinus densiflora,Robinia pseudoacacia plantation single growth model,from a perspective of the mathematics and biology in plantation growth dynamic,objectively reflect the four types of growth model of forest tree growth process simulation accuracy is higher,in plantation for the future of the business management and production practice provides an important decision basis,with high promotion value.