中文摘要：

用每木定位监测方法分析了后河自然保护区常绿落叶阔叶混交林1 hm2固定样地主要乔木树种6年的（2001～2007年）动态变化。样地主要分布有14种普通树种和5种珍稀树种。对这19个树种胸径≥5 cm的林木动态进行分析。2001年,样地有998株主要树种,到2007年,其中100株死亡,样地中新增81株更新幼树。19个主要树种基盖度从19.56 m2/hm2增加到20.14 m2/hm2,群落的径级结构没有明显变化,中等径级个体死亡率最高,且死亡植株在小尺度上聚集分布,较大尺度上随机分布,更新幼树几乎在所有尺度聚集分布,活树和死树在所有尺度空间正关联,活树和更新幼树在大部分尺度负关联。稀有濒危植物能长期稳定地在群落中存在,表明干扰、种内和种间竞争共同影响着群落的发展,群落处于动态平衡状态。

英文摘要：

The dynamics of common and rare tree species in a natural evergreen and deciduous broadleaved mixed forest were monitored over 6 years（2001-2007） in a 1 hm2 permanent plot in Houhe Nature Reserve,central China.The plot was dominated by 14 common tree species and 5 rare tree species.We focused on the dynamics of stems ≥5 cm DBH（diameter at 1.3 m above ground） of these 19 major tree species.Community ecology methods were used to measure and analyze changes in demographic and growth parameters of the major tree species.Spatial pattern of recruitment and mortality were also analyzed by point patterns analysis.Out of 998 stems,which were alive in 2001,100 died and 81 new stems developed over the 6-year period.The total basal area for the 19 major tree species was initially 19.56 m2/hm2,which increased to 20.14 m2/hm2 by 2007.There were no obvious differences in size classes for all major tree species,and mortality was the highest for the middle-sized trees.The spatial pattern of the dead stems for major tree species was random at larger scales and clumped at smaller scales.The recruited（new） stems were clumped at all scales.In addition,there was a positive interaction between the living stems and the dead stems,and a negative interaction between the living stems and the new stems at most scales.The results showed that disturbances and intra-and inter-specific competition were the major factors affecting the structure and dynamics of the rare plant community.The rare plant community also appeared to maintain a state of dynamic equilibrium.