安徽皇藏峪自然保护区青檀种群数量动态

根据野外调查资料编制皇藏峪自然保护区不同生境青檀种群的静态生命表,绘制存活曲线、死亡率曲线、消失率曲线以及4个生存函数曲线,分析种群数量特征。同时,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)不同生境青檀种群径级结构大体呈金字塔型,中、幼龄阶段个体数量丰富,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Vpi和Vpi’(考虑外部干扰时)均大于零。种群属稳定增长型。2)不同生境青檀种群在幼龄阶段死亡率较高,随着龄级的增加,死亡率逐渐降低。进入生理衰老阶段时,阳坡、阴坡种群死亡率再次上升,而坡谷种群由于老龄个体受到较好保护,死亡率略有下降。3)不同生境存活曲线存在差异,阳坡、阴坡种群趋于Deevey-Ⅱ型,坡谷种群趋于Deevey-Ⅲ型。4)生存分析表明,阳坡、阴坡种群具有前期锐减、中期稳定、后期衰退的特点;坡谷种群表现为前期锐减、中后期稳定的特点。5)在未来2年、5年中,不同生境青檀种群呈增长趋势。

Quantitative dynamics of Pteroceltis tatarinowii populations in Huangcangyu Nature Reserve of Anhui Province, East China

Base on the field survey data, the static life tables of Pteroceltis tartarinowii populations in different habitats of Huangchanyu Nature Reserve were established, and the populations’ quantitative characteristics were evaluated by analyzing the curves of survival rate, mortality rate, and vanishing rate as well as four survival function curves. The dynamics of the populations were also analyzed by the quantitative analysis of population structure and the time sequence model. In different habitats of the Reserve, the DBH structure of P. tartarinowii populations was overall presented as pyramid type, with relatively large amount of young- and middle-aged but less amount of old individuals. The populations had definite fluctuations in their growth dynamics, but the dynamic indices Vpi and Vpi′ (considering the external interferences) were both greater than zero. A stable-growth type population was thus shown in different habitats. The P. tartarinowii populations in different habitats had a higher mortality at young stage, but the mortality decreased gradually with increasing tree age. When entering into physiologically consenescence period, the populations’ mortality re-ascended on sunny and shady slope, but decreased slightly in valley due to the individuals better protected. The survival curves of the populations differed with habitats, inclined to be Deevey-Ⅱ type on sunny and shady slope and Deevey-Ⅲ type in valley. The four survival function curves indicated that the populations on sunny and shady slope was decreased rapidly at young, stable at mature, and declined at old stage, whereas the populations in valley was decreased quickly at young, and stable at mature and old stages. Time sequence model suggested that in the next 2 and 5 years, the P. tartarinowii populations in different habitats of Huangchanyu Nature Reserve would present a stable-growth trend.