关键词: 关键词：岷江冷杉, 空间分布格局, 空间关联, Ripley’s K 函数, 大小级, 亚高山

Abstract: Abstract: The location of every Abies faxoniana tree was mapped, and the diameter at breast height (DBH), height of each individual recorded in a forty years natural secondary forest. Trees were divided into five age classes according to their DBH and height. The spatial pattern was analyzed using point pattern analysis (Ripley’s K ) method. The results showed that Abies faxoniana distributed as a clumped population, five age classes exhibited clumped distributions at most spatial scales. The intensity of assemblage increased firstly, and then decreased with increasing scale and then tent to random distribution. There existed a critical scale in which distribution pattern transfered from clumped to random. Probably, the clumped distribution of big age classes was determined by the selectively cutting disturbances in the 60th of last century, the clumped distribution of small age classes was closely related to the way of seeds dispersal. All age classes present a positive association at fine scales. Spatial association turned from strongly positive association to zero with the increasing of scale. However, there were no negative associations in age classes at all scales, which indicated that the population had a harmonious relationship internally. Big trees and middle trees had positive association at all scales. Seedlings have positive association with saplings only within the scale of 7 m, but they had no associations with big, middle and small trees. Seedlings were independent of big age classes. Some corresponding measures can be taken to accelerate the proceeding succession to bamboo-Minjiang fir forest before the selective cutting, with the consideration of the population’s spatial property and the characteristics in different growth phase.

Key words: Key words: Abies faxoniana, spatial distribution pattern, spatial association, Ripley’s K, different size class, sub-alpine