极小种群野生植物馨香木兰的种群结构及动态

摘要

为了更好地掌握极小种群野生植物馨香木兰的种群结构及动态情况，通过对云南省西畴县馨香木兰群落24个样方的调查，分析了馨香木兰的高度结构、年龄结构、空间分布格局，编制了特定时间生命表，绘制了生存曲线。结果表明，馨香木兰高度结构完整，种群个体高度发育是连续的，在群落中属连续型种群；其相对年龄结构不完整，呈现明显的菱形，幼苗缺乏；其空间分布格局表现为集群分布，但到IV级立木阶段就已变成随机分布；其成长可分为幼苗、幼树、成树和老树等4个时期，幼树和成树时期死亡率最低，老树时期死亡率最高；其种群生存曲线接近于Deevey I型，种群正处于衰退状态。%In order to better understand the population structure and dynamics of Lirianthe odoratissma (Y.W.Law et R.Z.Zhou) N.H.Xia et C.Y.Wu, a plant species with extremely small populations, the height and age structure and the spatial distribution of its population were analyzed , the time-specific life table was estab-lished and the survivorship curve was drawn with the data of the survey of 24 sample plots of its communities in the Xichou county of Yunnan province .The results indicated that the height structure was complete .This implies that the population is successive in the height growth of its individuals and in community .The relative age structure is uncomplete and its histogram looks like a diamond while the numbers of seedlings are lacking and old trees are too less.Its spatial distribution pattern is of clump and that of the IV-class population become of poisson.Its develop-ment can be divided into 4 phases, namely seedling, young, adult and old phases.Its mortality rate is the lowest in the young and adult phases and the highest in the old phase .The survivorship curve is close to the type of De-evey I and this reveals that the population is declining .