濒危植物沉水樟的种群生命表和谱分析

将林木依胸径大小分级，以林木径级结构代表年龄结构。采用分段匀滑技术，编制沉水樟种群特定时间生命表，绘制死亡率曲线、危险率曲线及存活曲线，分析沉水樟种群动态趋势。结果表明：沉水樟种群的存活曲线趋于Deevey-Ⅲ型，幼苗和中树稀缺是导致沉水樟濒危的重要原因。沉水樟种群天然更新过程的动态是通过沉水樟不同龄级的株数分布波动而表现的，种群动态的谱分析表明沉水樟种群动态除受基波的影响外，还显示出明显的小周期波动，在11龄级这一小周期波动与沉水樟高生长有关，在15龄级这一小周期的波动可能与沉水樟的生理特性有关。

The population life table and periodic fluctuation of Cinnamomun micranthum, an endangered plant

Cinnamomun micranthum is a rare cash plant of Cinnamomun which occurs in mainland and Taiwan Province, China. It was listed as a Grade Three endangered plant for State protection in 1982 as its abundance was decreasing rapidly. The surviving Cinnamomun micranthum commonly has very low reproduction and natural regeneration ability. Although some studies have been recently conducted of the phenology, sexual reproduction and asexual reproduction of Cinnamomun micranthum, there has been no research into its population dynamics. In order to determine the population state of Cinnamomun micranthum, analyze its past population structure and pre-disturbance situation and forecast its future population dynamics, the population life table and periodic fluctuation of Cinnamomun micranthum were analyzed by the space deducing time method. The static state life table, the survival rate 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 Deevey-1I type. According to the mortality rate curve, the mortality peaks of Cinnamomun micranthum are in the first and fourteenth age grades. The high mortality of seedlings and middle-age trees was one of the main reasons which led the Cinnamomun micranthum population becoming endangered. The natural regeneration process of the Cinnamomun micranthum population can be represented by the fluctuation of the of the population showed that the natural regeneration fifteenth age grades. distribution of the number of trees in different age grades. Spectral analysis of Cinnamomun micranthum was a minor periodic change in eleventh and