Spatial Distribution Pattern of Pinus tabulaeformis Populations in North China
Three Pinus tabulaeformis plots along latitude from north to south (Heilihe Natural Reserve of Inner Mongolia, Songshan Natural Reserve of Beijing, Taiyueshan Research Station of Shanxi Province) were built in north China in 2007. Spatial pattern and spatial association of P. tabulaeformis at different growth stages were discussed based on Ripley' s K-function. Among the three plots, Heilihe had the highest density of tree stem and owned the most abundant seedlings and saplings, while Songshan had the lowest stem density, and big trees in Taiyueshan were richest. The stem densities of P. tabulaeformis with diameter at breast height greater than or equal to 1 cm in Heilihe, Songshan and Taiyueshan populations were 1741, 467 and 722 individuals per hectare, respectively. Ripley' s K- function showed that P. tabulaeformis in the three plots mainly had an aggregated distribution, and spatial patterns were various at different spatial scales. As population grew (from saplings to small trees and to big trees), it tended to be random distribution or less clumped, indicating the survival strategy and adaptability of P. tabulaeformis in certain degree. Spatial association was closely related to tree size, namely the associations would be more significant if there was less difference in tree size between saplings and small trees or small trees and big trees.
NETL
NSTL
万方数据
维普
