Abstract: Growth model is an efficient way to study growing process of some factors of plants quantitatively. Height growth of the Korean pine(Pinus koraiensis)was studied by means of hyperbola equation, Logistic equation, Richards equation with three parameters and four parameters in this paper. The results showed that Richards equation with four parameters was the most suitable and could become the other theoretical equations when some parameters were given different value. The maximum height of trees can be given in advance when Richards equation with four parameters is used, and it was even more corresponding to reality. In addition, a height growth model with real height of fixed age as a parameter was discussed in the paper. This kind of growth model can be used to calculate height growth of a given tree.

Key words: Aphis citricola, apple, selectivity, adaptability, age-stage two-sex life table.