色季拉山急尖长苞冷杉林下灌木群落空间格局及其与倒木关联性分析

分析西藏色季拉山急尖长苞冷杉原始林下灌木群落的空间分布格局及其与倒木的关联性，探讨该森林生态系统内灌木的分布规律，并从空间分布格局角度量化倒木对灌木分布的影响。以色季拉山急尖长苞冷杉原始林下灌木和倒木为研究对象，通过典型样地调查，用点格局法分析其空间分布格局以及与倒木的关联性。结果表明:1）样地内共有灌木7种，总密度730株·hm^-2，不同灌木种群分密度依次为杯萼忍冬（359株·hm^-2）>长尾槭（185株·hm^-2）>西南花楸（61株·hm^-2）>猴斑杜鹃（55株·hm^-2）>冰川茶藨子（53株·hm^-2）>光秃绣线菊（株·hm^-2）>峨眉蔷薇（株·hm^-2）；2）在0~50 m空间尺度内，冰川茶藨子、猴斑杜鹃、长尾槭、杯萼忍冬以集群分布为主要特征；西南花楸以随机分布为主要特征，只是在个别尺度呈现显著的集群分布；3）Ⅰ腐烂等级倒木与灌木在0~50 m空间尺度上呈显著的负关联，倒木整体与灌木及Ⅱ~Ⅴ腐烂等级倒木与灌木在0~50 m空间尺度上均无显著关联。不同灌木种群因对环境的适应性不同而具有不同的空间分布格局，灌木空间格局形成的生态过程及倒木对灌木空间分布的影响均具有复杂性。

SpatialPattern of Shrub Community and Its Correlation with Fallen Logs in Abies georgei var.smithii Forests in the Sejila Mountains

To analyze the spatial distribution pattern of shrub community and its correlation with fallen logs in primitive forest of Abies georgei var.smithii,distributed in the Sejila Mountain,Southeastern Tibet.To explore the distribution law of the shrubs in the forest ecosystem,and to quantify the influence of fallen logs on shrub distribution from the spatial distribution pattern.The typical plot method and spatial point pattern method were adopted used to investigate shrubs and fallen logs and correlationships.1) Seven kinds of shrubs were found in the sample plots with a total density of 730 plant·hm^-2.The densities of 7 shrubs were the order of Lonicera inconspicua（359）>Acer caudatum（185）>Sorbus rehderiana（61）>Rhododendron faucium（55）>Ribes glaciale（53）>Spiraea mollifolia var.glabrata（12）>Rosa omeiensis（5 plants·hm^-2）.2) Within the spatial scale of 0-50 m,R.glaciale,R.faucium,A.caudatum,and L.inconspicua exhibited aggregation distribution,while S.rehderiana was characterized by random distribution,but presented significant cluster distribution at individual scale.3) From 0 to 50 m spatial scale,the correlations between the downed logs of Ⅰ decay level and shrub were significant,but the correlations between the downed logs of Ⅱ-Ⅴ decay level and shrubs were not significant,and the correlations between downed logs as a whole and shrubs were also not significant.Different shrub communities show different spatial distribution patterns due to their adaptabilities to the environment.The ecological process of shrub spatial pattern formation and the influence of fallen logs on shrub distribution are complicated.