The Growth Simulation And Selective Technology Research Of Abies Nephrolepis (Trautv.) Maxim Natural Secondary Forest

The paper studied on growth rhythm of (Trautv.) Maxim natural secondary forest in Wang Qing. Jilin province. scientific theoretical basis for selective cutting utilization were formed by combining the empirical equation with theoretical equation to analysis the data of sample plot and parse tree in field, growing site and growth rhythm of Abies nephrolepis.1.By using Richard equation in the ForStat software, this article simulate the growth curve. According to the growth curve of tree-age and tree height from 96 parse tree, we divide the site condition of Abies nephrolepis (Trautv.) Maxim into three categories good, medium, poor2.This paper select parse tree under different site conditions and study on the growth rhythm of Abies nephrolepis (Trautv.) Maxim secondary forest,so we can provide scientific theoretical basis for selective cutting utilization. By making correlation analysis of the DBH and tree-age of Abies nephrolepis (Trautv.) Maxim natural secondary forest parse tree, as a result, the average DBH as the benchmark is reasonable in field investigation.3. Selective cutting technology system research of Abies nephrolepis (Trautv.) Maxim secondary forestâ‘  According to the growth rhythm of Abies nephrolepis (Trautv.) Maxim stand under different site conditions, we can know the best start period of diameter limit selection cutting and the standards of selective cutting wood. During the time, selective cutting can ensure high growth rate of Abies nephrolepis (Trautv.) Maxim secondary forest, be back to the level before cutting rapidly. At the same time, according to the research of DBH and heart rate of Abies nephrolepis (Trautv.) Maxim, we further improve the selection criteria of selective cutting wood. Combining with the growth rhythm and heart rot rhythm of Abies nephrolepis (Trautv.) Maxim secondary forest under different site conditions. The research get the following conclusions:Under the good site condition, when the average DBH of Abies nephrolepis (Trautv.) Maxim is about 18 cm, we cut the trees of 30cm and we can achieve the best returns; Under the medium site condition, when the average DBH of Abies nephrolepis (Trautv.) Maxim is about 24 cm, we cut the mature trees and we can achieve the best economic benefit; Under the poor site condition, the mature time of Abies nephrolepis (Trautv.) Maxim appeared comparatively late, and the condition of heart rot is serious, we suggest that according to the need of the actual situation we should cut the mature tree as early as possible.â‘¡ This paper study on the selective cutting technology of Abies nephrolepis (Trautv.) Maxim secondary forest under different site conditions, In combination with the stipulate of the intensity of forest selective issued by the State Forestry Bureau, the research get the following conclusions:Under the good site condition,20% forest were selected as cutting intensity, when they were 20 years. Then, under the medium site condition,10% forest were selected 10 years as a selective cutting cycle, when they were 19years. While,0-5% forest were selected to the actual situation needs, under the poor site condition.