陈和洞自然保护区常绿阔叶林结构多样性研究

Structural Diversity in the Broadleaved Evergreen Forest of Chenhedong Nature Reserve,Guangdong Province,China

根据样方调查数据,以空间变化、物种多样性及树木大小3个指标分析了广州从化陈和洞自然保护区常绿阔叶林的结构多样性.3个样地群落组成的对比表明,25个共有种均是亚热带常绿阔叶林的特征成分,包括赤楠蒲桃Syzygium buxifolium、网脉山龙眼Helicia reticulata、华南樟Cinnamomum austro-sinensis、硬斗石栎Lithocarpus hancei、白锥Castanopsis fabric等.上库(SK)和上库南坡(SKN)林分的丰富度差异不显著,但与上库山顶西坡(SKX)的差异显著(P<0.01),SK及SKN群落冠层的优势现象更明显,样方多度平均值均较低.SKX群落的Simpson指数、Shannon-Weiner指数及均匀度指数的变化均比SK和SKN的缓和.3个林分乔木的树高和胸径变化总趋势均为小级别的个体占多数,SKN群落树木的平均树高和平均胸径均明显高于其他2个样地,SK次之,SKX的最小,说明生境条件的差异对森林群落结构多样性和群落空间异质性有重要的影响.

Based on the data collected from sampled surveys in the field work,spatial distribution,species diversity,and variations in tree dimensions in the broadleaved evergreen forest stands in Chenhedong Nature Reserve were analyzed.A comparison of the community composition between the three sites indicated that 25 shared species were characterized by floristic elements of the typical subtropical broadleaved evergreen forest,including Syzygium buxifolium,Helicia reticulate,Cinnamomum austro-sinensis,Lithocarpus hancei,and Castanopsis fabric,etc.The abundance of Shangku stand（SK） was not significantly different from that of the southern slope of Shangku stand（SKN）,but both were significantly different from that of western slope on the mountaintop of Shangku（SKX）（P〈0.01）.The dominant phenomenon in the canopy layer was more conspicuous at SK and SKN stands,with low average abundance by quadrats.Variability in Simpson index,Shannon-Weiner index,and evenness index at SKX stand was moderate as compared with that at SK and SKN stands.All of the 3 stands showed a trend in concentration of individuals in small DBH or height class,with the mean of tree height and DBH from SKN stand significantly greater than that from SK and SKX stands.The findings from this study demonstrated that differences in stand condition had an important effect on structural diversity and spatial distribution of forest communities.