孑遗植物水松(Glyptostrobus pensilis)种群生命表和谱分析

The Population Life Table and Periodic Fluctuation of the Relict Plant Glyptostrobus pensilis

对屏南水松(Glyptostrobus pensilis)种群依胸径大小分级,以林木径级结构代替年龄结构,采用匀滑技术,编制水松种群静态生命表,绘制死亡率曲线、危险率曲线及存活曲线,分析水松种群动态变化趋势。结果表明,水松种群的存活曲线趋于Deever-Ⅲ型,幼苗稀缺是其濒危的重要原因之一。水松种群天然更新过程是通过水松不同龄级的株数分布波动而表现的,谱分析表明,水松种群动态不仅受基波影响,而且在第10龄级呈现较小的周期波动,其机制与水松高生长特性有关。

In order to determine the population state of Glyptostrobus pensilis, analyze its past population structure and pre-disturbance situation and forecast its future population dynamics, the population life table and periodic flutuation of G. pensilis were analyzed by space deducing time method. The static life table, the survivorship curve, the mortality rate curve and danger rate were compiled using the diameter at breast height class to represent the age class structure and smooth out technique. The results showed that the survival curve of the population appeared to be of the Deever-Ⅲ type. The high mortablity of seedlings was one of the main reasons which led the G. pensilis population becoming endangered. The natural rege-neration process of the G. pensilis population can be represented by the flutuation of the distribution of the number of trees in different age grades. Spectral analysis of the population showed that the natural rege-neration of G. pettsilis was a minor periodic change in the tenth age grades.