东北林区森林资源可持续特征模型研究

STUDY ON NORTH-EAST FOREST RESOURCE SUSTAINABLE MODEL

本文从法正林的数学模型出发 ,利用天然同龄林的固定小班间隔近 4 0a的龄级转移观测资料 ,经龄级转移期的处理 ,构造出天然林林龄可持续转移模型P′S′ =λS′ ,其中特征根λ均为 1。分析稳定状态S′的结构 ,发现了天然林林龄滞留转移现象 ,并由此获得天然同龄林可持续的林龄向量应是呈递增的等差级数。根据滞留量的大小 ,可以把天然林可持续转移模型分成 3类。并指出产生上述现象的林学机理是林木枯损概率随着林木年龄的加大而增长。

This paper started from normal forest equation model,based on the 40 years'observation data of natural even\|age stable sub\|compartment,dealt with forest age class transfer,and constructed natural forest age class transfer sustainable model:P′S′=λS′,where characteristic root ( λ ) was 1.By analysing the structure of stable state S’,the natural forest age retard was discovered and natural even\|age forest sustainable age vector was equidifferently ascending.According to the amount of retard,the natural forest resource transfer sustainable models were divided into three types.It also pointed out that the forestry mechanism of phenomena above\|mentioned was the probability of forest tree withering and damage increasing with its age increase.