珍稀濒危植物桫椤种群结构与动态研究

采用空间序列代替时间变化的方法,对7个地段中的桫椤种群大小结构进行分析,运用C、K、m^*、m^*/m和Iδ5种聚集度指标测定不同地段内桫椤种群的空间分布格局及其动态,并根据植株个体点位图,考察桫椤种群在不同取样尺度上的空间分布格局.结果表明,不同地段中的桫椤种群结构存在增长型、稳定型、成熟型和衰退型4种类型;不同地段中的桫椤种群空间分布格局有所差异,表现为集群分布或随机分布;在桫椤种群生长过程中,分布格局从集群型向随机型转变;种群扩散型指数Iδ随取样尺度的增大而减小.

Population structure and its dynamics of rare and endangered plant Alsophila spinulosa

This paper analyzed the population structure of Alsophila spinulosa in seven plots by the method of spatial sere substituting for time sere, and measured its spatial distribution pattern and dynamics by applying five aggregate indices, C, K, m*, m*/m and Idelta. The spatial distribution pattern with different quadrat scale was examined, according to the map of individual location. The results indicated that the population structure of Alsophila spinulosa in the seven plots presented growing, stable, adult or senescent type, and the spatial distribution pattern was changed from clump to random with the development of Alsophila spinulosa population. The values of dispersion index Idelta of the population decreased with increasing quadrat scale.