Abstract:

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.

Key words: Mathematical model of normal forest, Age-class transfer retarded phenomena, Forest sustainable model