Abstract: Pinus bungeana is an important protective plant. Spatial pattern analysis of individuals in different age-classes of P.bungeana was conducted in the present study. Here we employed the technique of point pattern analysis which can analyze patterns under all scale along a gradient. The results showed: The densities of six age-classes were more different, and age-classes 2~5 had more individuals than the other two age-classes. The individuals of all age-classes were not clumping distributed in space, however their distribution pattern trended to random distribution varied with the change of scale. The co-relationship between age-class 1 and age-class 2 was significantly positive, this significantly positive correlation is beneficial for the development of the group. In the smaller scale, the individuals of different age-classes were a stronger spatial association. When the scale was larger, their spatial association would be weakened greatly. This showed the spatial patterns of different age-classes individuals and the spatial association between the individuals had a close relationship with the spatial scale.

Key words: population pattern, Pinus bungeana forest, point pattern analysis, age-class