腾格里沙漠东南缘不同生境油蒿种群的数量动态

Numeric Dynamics of Artemisia ordosica Population under Different Habitats in Southeastern Edge of the Tengger Desert

对腾格里沙漠东南缘不同的生境条件(包括始建于1964年的人工植被区和天然植被区)下油蒿(Artemisia ordosica)种群调查取样,按照植株的体积大小分为7个龄级(Ⅰ,0~2cm3;Ⅱ,2~5cm3;Ⅲ,5~10cm3;Ⅳ,10~15cm3;Ⅴ,15~20cm3;Ⅵ,20~30cm3;Ⅶ,>30cm3),分析了种群的组成、静态生命表和存活曲线。结果表明:人工植被区油蒿种群的总体规模大于天然植被区,幼龄个体占有很高的比例;天然植被区油蒿的死亡率低于人工植被区,天然植被区Ⅰ和Ⅱ龄级油蒿种群的死亡率最高,人工植被区Ⅴ~Ⅶ龄级的油蒿种群死亡率最高;天然植被区油蒿种群的稳定性维持主要通过幼苗的更新,而人工植被区可通过幼苗的自我更新和大龄植株的自疏作用;Ⅴ龄级的油蒿个体是种群中的生存质量最佳的个体;两种生境下油蒿种群均符合DeeveyⅡ型存活曲线。

In this paper,we sampling surveyed on the Artemisia ordosica population under different habitats（include artificial vegetation area established from1964 and natural vegetation area）in southeastern edge of the Tengger Desert.The A.ordosica population was divided into seven age-class according to the volume level.We analyzed the composition of population,static life table and survival curve.We developed the following conclusions：（1）The overall size of the A.ordosica population in artificial vegetation area is larger than in natural vegetation area.High proportion of A.ordosica population is young individuals in two habitats.（2）The death rate of A.ordosica population in natural vegetation area is lower than in artificial vegetation area.The age-classⅠand Ⅱof A.ordosica population in natural vegetation area have the highest death rate and the age-class from ⅤtoⅦin artificial vegetation area have the highest death rate.（3）The stability maintenance of A.ordosica population in natural vegetation area is mainly through seedling regeneration.In artificial vegetation area,the stability maintenance through seedling regeneration and self-thinning effect of older individuals.（4）The age-classⅤof the A.ordosica individuals have best quality of life in population.（5）The population survival curves in different two habitats were close to Deevey-Ⅱtype.