百山祖中山中亚热带常绿阔叶林群落5年动态特征

为了解分布在中国东部中山地带典型的中亚热带常绿阔叶林的短期群落动态，于2003年和2008年，对面积为5hm。的百山祖森林动态样地进行2次全面调查，分析群落内主要树种的补员和死亡情况。结果表明：①从2003年到2008年，该样地内胸径≥1cm的植物共有2343株死亡，占样地内个体总数的7．79％，分属于96个物种，占物种总数62．75％。5a间，新增加的胸径≥1cm的木本植物中共有1131株，占样地内个体总数的3．93％。有补员个体的物种共计65种，占物种总数的36．72％。②百山祖5hm。样地，胸径≥1cm的所有个体的年死亡率为1．45％，年补员率为0．62％。灌木的年平均死亡率超过2．00％，高于其他生活型功能群，而4个生活型功能群的年平均补员率差异不大。③样地内主要树种胸径≥1cm的个体5a内的年平均死亡率为1．55％，年平均补员率为0．78％。30个主要树种的死亡率、补员率以及适合度差异较大，死亡率和补员率跟物种多度之间并没有相关性。这些结果显示：百山祖中山中亚热带常绿阔叶林群落近期出现了一定的更新困难，但物种组成基本稳定；种群动态存在较大的种间差异，且与生活型和多度的关系不显著。

A 5-year mid-mountain subtropical evergreen broadleaved forest study Baishanzu,east China

Population dynamics of primary forest species are important for a stable community structure and function. To explore mortalities, recruitments, fitness and changes of population size of the primary forest species in a mid-mountain, subtropical evergreen broadteaved forest in a short term, how do these parameters differ with species life form, and finally the community dynamics of the forest, a 5 hm2 plot （250 mx200 m） was established in 2002 on the north slope of Baishanzu Peak in Fengyangshan-Baishanzu National Nature Re- serve, east China. In 2003, all 30 092 woody plants alive ~ith a DBH （diameter at breast height）I〉 1 cm were tagged, mapped, measured, and identified by species. In 2008, all these woody plants were mea- sured, their living states were examined, and other individuals reached 1 cm DBH during the 5-year term were tagged, mapped, measured, and identified by species. Based on two datasets from censuses in 2003 and 2008, living, dead and recruited plants were grouped into canopy, mid-story, understory tree and shrub （4 functional groups）, and analyzed to estimate annual mortality, recruitment rates and fitness of 30 tree species, and the species composition dynamics of the community were determined with non-metric muhidi-mensional scaling （NMS）. Results showed that （1） compared to plants living in 2003, over five years a total of 2 343 stems （7.79%） belonging to 96 species had died, and 1 131 stems （3.93%） comprising 65 species （36.72%） reached 1 cm DBH. （2） Of all species in the plot, the average annual mortality rate was 1.45%, and the average annual recruitment rate was 0.62%. The annual mortality rates of 4 functional groups were 1.19%, 1.95%, 1.30%, and 2.59% respectively, while the annual recruitment rates of them were 0.67%, 0.92%, 0.68% and 0.92%. （3）For the 30 major species, the average annual mortality was 1.55%, the average annual recruitment rate was 0.78%, and the annual mortality as well as the recruitment rate and fitness, which were all unrelated to abundance of species. （4）The Change of species composition of the community during the 5 years was mild, comparing to the difference in species composition catised by spatial heterogene- ity of the plot. Thus, the mid-mountain, subtropical evergreen broadleaved forest had difficulty regenerating itself and independent of functional group and abundance, while the structure of the community was relatively stable during the 5 years.