长白山云冷杉针阔混交林两个演替阶段乔木的种间联结性

基于2×2联列表和方差比率,通过χ2统计量检验和种间联结系数值计算,对杨桦次生林和云冷杉针阔混交林阶段林分总体种间联结性进行了分析。结果表明：杨桦次生林群落内出现的12个乔木树种之间的总体关联性方差比率为0.932,接近1,表现为无相关性;在针阔混交林阶段,群落主要种间的总体关联性表现为正相关,说明该阶段的群落已处于和...

Interspecific association among arbor species in two succession stages of spruce-fir conifer and broadleaved mixed forest in Changbai Mountains,northeastern China

Based on the use of variance ration (VR), 2×2 contingency table,χ2 test and interspecies association coefficient calculation, we examined interspecific association of dominant species both in polar-birch secondary forest and in spruce-fir forest. The results showed that mean variance of the 12 principal arbor species in poplar-birch secondary forests was 0.932, closes to 1, and had no significant correlation; but in spruce-fir mixed forest, it showed positive correlation, which indicated that the stage was relatively stable and adapted to the environmental conditions. The positive correlation of the whole community was strengthening along with the progression of succession. The end-result of competition would lead to the pioneer tree, Betula platyhylla and Populu. davidiana, which were declining species, be replaced by the zonal climax species spruce-fir forest in the future. The overall correlations among multi-species reflect the general trend among various species in community. The interspecific association further explains that the community we studied is in the transitional stage, ie from the polar-birch secondary forest to spruce-fir mixed forest.