安徽琅琊山青檀种群数量动态

Dynamics of Pteroceltis tatarinowii Population in Langya Mountain of Anhui Province

以种群生命表和生存分析理论为基础,采用胸径大小分级法和分段匀滑技术,编制琅琊山青檀(Pteroceltistatarinowii)种群静态生命表,绘制了死亡率曲线、消失率曲线、存活曲线和生存函数曲线并分析种群数量特征,结合种群动态量化方法和时间序列预测模型分析种群数量动态变化。结果表明:(1)琅琊山青檀种群属稳定增长型。种群径级结构大体呈倒"J"型分布,中、幼龄阶段个体数量较为丰富,老龄阶段个体数量相对较少,种群在发育过程中存在一定波动性,但种群数量变化动态指数Vp,i和Vp,i'(考虑外部干扰时)均大于0。(2)青檀种群死亡率曲线和消失率曲线变化趋势基本一致,均出现2个高峰,一个出现在第Ⅱ龄级,另一个出现在第Ⅺ(或Ⅻ)龄级;存活曲线经统计检验趋于Deevey-Ⅱ型。(3)青檀种群的生存率曲线单调下降,累计死亡率曲线单调上升,生存率下降趋势表现为前期高于后期,累计死亡率则相反;生存函数曲线显示,青檀种群具有前期薄弱、中期稳定和后期衰退的特点。(4)在未来2、4、6、8和10 a内,青檀种群幼龄级个体数量相对丰富,种群呈稳定增长趋势。

Based on the theories of population life table and survival analysis, a static life table and curves of the survival rate, mortality rate and vanishing rate as well as survival function curve, of Pteroceltis tatarinowii population in the Langya Mountain of Anhui Province were worked out for analysis of quantitative characteristics of the population using the diameter at breast height （DBH） classification method and the section smoothing technique. Further on for analysis of dynamics of the population quantity the method of quantification of population dynamics and the time series prediction model were used. Results show that 1 ） the population of Pteroceltis tatarinowii in the Langya Mountain is of the type of steady growth. The structure of DBH class of the population appeared roughly in the shape of an invert ＂J＂ ; trees middle and young in age were relatively high in number, but those old in age relatively low. Although the population may be subject to certain fluctuation during its development process, the two dynamic indexes of Vp,~ and Vp,~＇ （taking into account the external in- terference） of the population quantity were both higher than zero. 2） The curves of the mortality rate and the vanishing rate of the population varied in a similar trend, each with two peaks popping up at the 2nd age class and the other at the 11th or 12th. Statistic test shows that the survival rate curve tends to be of the type of Deevey-]]. 3） The survival rate of the population decreased monotonically, while the cumulative mortality rate increased in the same manner. The falling trend of the survival rate was more apparent in the early stage than in the late stage, whereas that of the cumulative mortal- ity rate was just the reverse. The survival functional curve shows that the Pteroceltis tatarinowii population is characterized by weakness in the early age period, stableness in the middle age period, but decline in the old age period. 4） The time sequence model predicts that young individuals would be relatively abundant, and the population will show a trend of steady growth in the next 2, 4, 6, 8 and 10 years.