Abstract: In Huoshan Qiliyu woodland, a field survey was made on the typical Pinus tabulaeformis, and the distribution of P.tabulaeformis at different age-classes and its co-relationship were studied. The results show that: (1)The distribution of the age-classes appears kurtosis, i.e. the majority is the middle-aged, 20-30 cm, whereas the numbers of young and old are comparatively less; (2)The spatial distribution of these seven age-classes tends to be in groups, in which ages 4, 5 and 6 are more obvious. Meanwhile, it centralizes in groups in small-scale and tend to be in random distribution in large-scale; (3)The co-relationship between different age-classes is significantly positive correlated, of which ages from 3 to 5 are more significant. This significantly positive correlation is beneficial for the P.tabulaeformis to make full use of the resources in order to guarantee the living and development of the groups.

Key words: Pinus tabulaeformis, point pattern analysis, sampling scale, age-class, spatial association