山西南部翅果油树种群动态与谱分析

从种群生态方面，探讨山西南部濒危树种——翅果油树（Elaeagnus mollis Diels）的濒危机制，具有重要的科学价值。本文利用生存分析理论研究了翅果油树种群径级结构，编制了特定时间生命表，并绘制存活曲线、死亡曲线等曲线，同时又分析了生存率、积累死亡率和死亡密度等生存函数；而且应用谱分析理论分析了翅果油树种群的周期性。结果表明：（1）径级结构分析说明翅果油树种群属于增长型。（2）生命表分析表明，翅果油树种群损失度动态趋势和死亡率变化基本相似，呈现波动变化。存活曲线经统计检验更趋于DeeveyⅡ型。生命期望在17～21 cm径级出现高峰，说明此径级阶段翅果油树的生存质量相对较高。（3）生存函数分析表明，积累死亡率单调增加，生存率单调下降，其增加或下降幅度是前期高于后期。死亡密度函数曲线和死亡曲线变化趋势基本一致，危险率函数曲线也和死亡率变化趋势一致。（4）谱分析表明在自然更新过程中翅果油树种群动态表现出大周期内的小周期迭加现象，并且受基波的影响较大。

Spectral and Dyhamics Analysis of Elaeagnus mollis Diels Population in the South of Shanxi Province

It is very valuable to discuss the endangered mechanism of Elaeagnus mollis Diels, endemic to China, which is seriously in danger presently. Based on the theory of survival analysis, the size-class structure was studied, the time-specific life table, curve of survival, and curve of mortality were drawn, and at the same time, survival functions of survival rate, cumulative mortality rate and mortality density were analyzed. With the theory of spectral analysis, the fluctuation of population was also analyzed. The main results are as follows: (1) the size-class structure of the whole population is of increasing type. (2) the time-specific life table shows that the change of mortality rate fluctuates, which is similar to that of killing power. The curve of survival generally trends to be DeeveyⅡtype according to statistical test, and the peak of expected life appears at 17 to 21 size-class. (3) the 4 survival functions show that the change of population in early stage is bigger than that in the late stage. The change of mortality numbers shows a considerable similarity to that of mortality density, and the change of endangered rate is similar to that of mortality rate. (4) the spectral analysis indicates that, in the natural regeneration, the small period overlaps within the big one, and the period is greatly affected by fundamental wave.