Study On Tree Growth Models Of Main Tree Species In The Coniferous And Broad-leaved Mixed Forest In Jiaohe,Jilin

This study was based on the natural conifer and broad-leaved mixed forest in Jiaohe,Jilin.The data obtained from the initial census and recensus of the fixed observational plot in 2010 and 2015,including tree diameter at breast height(DBH),tree height and relative position,were used to establish diameter growth models,tree height curve models and individual tree mortality models for Acer mono,Fraxinus mandshurica,Pinus koraiensis,and Tilia amurensis.Different models were used to explore the influence of tree size and tree competition on tree diameter growth,tree height-diameter relationship,and tree death.In diameter growth models,the performance of the nonlinear growth models were superior to the linear growth models.The optimal model of Acer mono,Fraxinus mandshurica,and Pinus koraiensis contained competition index,while the diameter growth of Tilia amurensis was only determined by the initial diameter.In tree height curve models,the Weibull model had the best performance.The competition intensity contributed to the relationship between tree height and DBH.Plants with similar competition strength had more consistent relationship of tree height and DBH.The optimal single tree mortality model of Acer mono contained competition index,while that of other species did not.The results verified the general rules of relationships between mortality and tree size:the mortality of small trees and large trees was higher compared with medium trees.The individual tree growth models can be used to predict growth and death dynamics of the temperate coniferous and broad-leaved mixed forest,which will provide theoretical support for the management of natural mixed forests.