恩施不同红椿群落α多样性与种群分布格局相关分析

为研究恩施地区红椿(Toona ciliata Roem.)群落α多样性与红椿种群空间分布格局的相关性,采用样方法对恩施4个不同红椿天然群落样地进行调查。对群落α多样性指数与种群空间分布格局相关性分析表明,群落草本与灌木层α多样性指数相关性较低;草本与乔木层α多样性指数之间存在较强负相关;灌木与乔木层α多样性表现为显著或极显著正相关。红椿群落群层间α多样性与种群分布格局相关性表明,群落草本层的多样性与红椿种群分布格局间相关性较低;种群分布格局与灌木和乔木α多样性呈高度负相关。研究表明,群层间α多样性存在较为不同的相关性,可能是由于竞争中不平等的资源分配,影响红椿群落物种的演替方向;红椿群落乔灌层的α多样性指数越高,对红椿种群的分布格局影响越大,促使红椿种群分布格局趋于泊松分布。

Correlation Analyses on α Diversity of Different Toonas ciliata Communities and Population Distribution Pattern in Enshi Region

Targeting the correlation between α diversity of different Toona ciliata Roem. communities and population distribu-tion pattern in Enshi Region,the quadrat sampling method was employed to survey four T. ciliata communities. The correlation analyses on α diversity of the four communities and population distribution pattern indexes were conducted and the results re-vealed that the various α diversitiey indexes of herb layers and shrub layers had insignificant correlation;the α diversitiey in-dexes between herbs and trees were negatively correlated;the α diversitiey indexes between shrubs and trees illustrated signifi-cant positive correlation,some even having highly significantly positive correlation. The correlation analyses between various αdiversity indexes and population distribution patterns indicated the correlation between α diversity indexes and distribution pat-tern indexes was comparatively low,but the α diversity indexes of shrubs and trees were highly negative correlated with those of distribution patterns. The research showed that α diversity indexes of various vegetation layers had various correlation,which might result from unbalanced resource distribution in the competition,which might direct the succession of different species;the higher the α diversitiy indexes of shrub and treee layers, the stronger the impact on population distribution patterns, which prompted T. ciliata population to accord the competition in Poisson distribution pattern.