Based on survey data of a 0.32 hm2 plot in Beijing Jiulong Mountain,the spatial structure diversity of a Platycladus orientalis plantation was analyzed using traditional approaches and a bivariate distribution of three structural parameters,i.e.,uniform angle index (W),dominance (U) and mingling (M).The community structure was relatively simple.The P.orientalis population was in an obviously dominant position,and in a state of low mingling,insignificant size differentiation and uniform distribution,while other accompanying species were in a state of high mingling and relative disadvantage.The diameter and height distribution of the stand presented as unimodal.59％ of individual trees in the P.orientalis forest were surrounded by the same species,and 22％ were surrounded by only one other species among their nearest four neighbors,i.e.,the forest was in a state of low mingling.More than half (52％) of the trees in the plot were in a random pattern,in which most trees (57％) were surrounded by the same species,while 50％ of the trees in high mixture (mingling=0.75,1.00) were randomly distributed.The trees of different extents of dominance had a similar frequency,but the number of dominant trees was slightly more than that of non-dominants,and most of the dominant trees were in a state of low mingling and random pattern.The spatial diversity in the P.orientalis plantation resulted from mingling and diameter differentiation.Such a result was not only closely related to the development stage of community but also connected to its origin,anthropogenic disturbance and species composition.
Jiulong MountainPlatycladus orientalisspatial diversitystructural parameterdiameter distributionbivariate distribution
国家科技期刊平台
NSTL
万方数据
维普
