仙湖苏铁群落主要种群的空间分布格局

The Spatial Distribution Pattern of Main Populations in Cycas Fairylakea Community

通过测定仙湖苏铁群落立木层及林下层各15个主要种群的空间分布格局,探讨仙湖苏铁群落的组成结构及演替趋势,为仙湖苏铁野生种群的保护提供科学依据.结果表明:立木层中假苹婆、降真香、鼠刺、银柴、水团花5个种群分布格局均为集群分布,且聚集强度大;山牡荆、罗伞、黄牛木,罗浮柿等种群的分布格局也为集群分布,但聚集强度小;鸭脚木、山乌桕、簕欓、狗骨柴,水翁、猴耳环等种群呈随机分布.林下层中仙湖苏铁种群呈集群分布,且聚集程度较大;假苹婆、鼠刺、降真香、鸭脚木、簕欓、狗骨柴等树种的幼树均呈集群分布.分布格局在一定程度上反映了群落的组成及发育状况,减少人为影响干扰,使群落向以中生性树种为优势种的顶极群落演替对该种群的发展是有利的.

Population spatial distribution pattern of 15 main populations of stand layer and undergrowth in Cycas fairylakea community was investigated, in order to discuss the structure and succession direction and provide scientific foundation for the protection of C. fairylakea wild population. The results indicated that spatial distribution of five dominant populations such as Sterculia lanceolata, Acronychia pedunculata, Itea chinensis, Aporosa dioica and Adina pilulifera, were of aggregate type with great clumping intensity. Other main populations, such as Vitex quinata , Ardisia quinquegona , Cratoscylura cochinchinense and Diospyros morrisiana were distributed aggregately with smaller clumping intensity. However some main populations such as Sche f flera octoph ylla , Sa pium discolor, Di plospora dubia , Cleistocalyx operculatus and Pithecellobium clypearia, distributed randomly. C. fairylakea population in undergrowth were distributed aggregately with great clumping intensity. The saplings of many main populations, i. e. , Sterculia lanceolata , Acronychia pedunculata , Itea chinensis , Sche f flera octoph ylla , Diplospora dubia , Cleistocalyx operculatus, were of aggregate distribution. The spatial distribution pattern of these populations showed the constitute and growth of C. fairylakea community. It is advantageous to C. fairylakea population that decreases disturb of human activity and advances the community to climax with dominant mesophilous tree species.