南岭国家级自然保护区常绿阔叶林主要树种的种间分离

种间分离的研究对揭示种间相互作用、群落组成与动态具有重要意义。本研究在南岭国家级自然保护区的常绿阔叶林内,设置了36个样方,以样方内株数≥10的27个物种为研究对象,在样方调查的基础上,运用ArcGIS软件、N×N最近邻体列联表、2×2列联表截表以及Pielou分离指数,研究了群落内27个物种的种间分离规律,采用Clark_Evans最近邻体法测定了27个物种的分布格局。结果显示:(1)27个物种中,有3个呈聚集分布,24个呈随机分布;(2)常绿阔叶林植物群落中正分离种对占59.83%,随机毗邻种对占40.17%,没有负分离,群落稳定;(3)正分离主要发生在群落优势种或建群种之间,优势种之间也有随机毗邻发生;(4)呈聚集分布的物种与其它物种主要表现为正分离,一般不表现为负分离;而呈随机分布的物种之间多数表现为随机毗邻,也有部分表现为正分离或负分离;(5)群落内27个物种互相交错分布,是全面不分离的。

Interspecific Segregation in the Main Species of Evergreen Broad-leaved Forest in Nanling National Nature Reserve,Guangdong Province

Analyzing interspecific segregation helps reveal species interactions, community structure and dynamics. We established 36 quadrats and drew a distribution map for 27 species numbering 10 or more. Using ArcView GIS software and the nearest-neighbor method, interspecific segregation was studied with an N ×N nearest-neighbor contingency table, a 2 ×2 nearest-neighbor contingency sub-table, and Pielou's coefficient of segregation for the individual tree species. Distribution patterns were measured by a revised Clark-Evans index (CE) and the widely-used χ² method. Results showed that:(1) three tree species were clumped, and the others were random;(2) Most species pairs were positively segregated (59.83%), some species pairs were randomly segregated (40.17%), and no species pairs were negatively segregated;(3) Some differences existed among different species in the interspecific segregation of all species. Larger individuals representing dominant species in the communities tended to be positively segregated with other large trees, though sometimes tended to random segregation;(4) Interspecific segregation was closely related to distribution patterns. There was a larger proportion of positive segregation between clumped species and other species than there was negative segregation. Most random segregation occurred between random species, which also caused slight positive or negative segregation;(5) The 27 species overlapped in distribution and were characterized by overall non-segregation.