濒危植物南方红豆杉种群克隆生长空间格局与动态

在南方红豆杉集中的广西元宝山林设置样地．采用相邻格子样方法和T形距离取样离法调查取样 。应用方差/均值比的t检验法判定种群分布格局类型，用负二项参数 格林指数、Moristita指数 、丛生指标、平均拥挤度和聚块性指数、T形距离指数等方法测度集聚强测度，对南方红豆杉种群克隆生长的空间格局及动态进行研究。结果表明：整个种群在10mX10m、10mX5m、3mX2m等不同空间尺度下均表现为集聚分布格局,但集群强度不高。在种群生活史中，从幼苗到大构树，集群程度减小，大树呈随机分布。南方红豆杉有强烈的萌生能力，大量产生萌生分株，幼苗期剧烈的种内和种间竞争作用，导致个体密度下降、集群程度降低，种群表现扩散趋势，而小树、中龄树因占据了所需的生态位空间，种内竞争相对减缓，集聚强度有所增强，随个体生态位空间的扩张，种内和种间竞争重新加剧，种群密度下降，种群空间格局转为随机分布。南方红豆杉种群不同大小级分布格局这种动态变化反映了种群在生长发育过程中的生态策略和适应机制。

Study on Floristic and Ecology of Species Endemic to Xinjiang

In Xinjiang,the environmental complexity brings on species diversity.The results showed that there are 268 endemic species in 119 genera of 38 families in Xinjiang.They are rather indigent and origin younger but most of them are distributed in mountain system.So we should protect these key endemic species and their sensitive occurring areas.In order to understand and investigate Xinjiang flora''s characteristics,origin and evolutive rule,the floristic and ecological characteristics of endemic species are studied in present paper.