山西灵丘天然青檀种群数量动态

Quantitative dynamics of natural Pteroceltis tatarinowii population in the Lingqiu Pteroceltis tatarinowii Nature Reserve,Shanxi Province

青檀是我国特有的珍稀濒危植物,为了更好地了解该种群数量动态,保护该种群持续稳定发展,在山西灵丘青檀自然保护区内采用样方法调查了青檀种群,编制种群静态生命表,绘制存活曲线,死亡率曲线和消失率曲线,引入生存函数,运用种群动态量化分析方法对种群动态变化进行分析。结果表明:种群数量变化动态指数大于零,种群属于增长型,但种群在发展过程中存在波动性;存活曲线拟合结果表明种群趋于DeeveyⅡ型。种群死亡率和消失率曲线变化趋势基本一致,在第3龄级出现高峰。生存率和累计死亡率曲线在前期变化幅度较大,后期两曲线变化趋于平缓;死亡密度前期高于后期,而危险率随着龄级的增加不断增大。

Pteroceltis tatarinowii is an endangered and endemic species in China. To better understand the quantitative dynamics of Pteroceltis tatarinowii population and to facilitate its sustainable and steady development, the method of quadrat investigation was adopted in Lingqiu Pteroceltis tatarinowii Nature Reserve. The static life table ofPteroceltis tatarinowii population was established. The population dynamics was analyzed by the curves of survival rate, mortality rate and vanishing rate. At the same time, survival functions, quantitative analysis methods of population dynamics were used. The results are as follows： The dynamics indices of population quantitative change were greater than zero. The age structure of population was in growth pattern, but fluctuation existed in the process of population development. The fitting results showed that survival curve of population appeared to be of Deevey II type. The mortality rate curve and disappearance rate curve had similar variation trend with the peaks in the 3rd age class periods. The varied ranges of survival function and the cumulative mortality function were larger at early stage than at late stage, and the variation trend of two curves tended to be gentle at late stage. The mortality density was higher at early stage than at late stage, but the hazard rate curve was increasing with the growth of age class.