中国沙棘种群分株克隆生长型动态研究

中国沙棘分株克隆生长型可分为单轴型及合轴型2种，它们在种群中的数量和比例变化具 有生态适应意义。为了探讨克隆生长型随种群年龄增长的变化规律，采用“空间差异代替时间变化 法”和“样地编年序列法”分析了克隆生长型的时间动态。结果表明，通过分株及其分蘖的出生与死 亡调节，中国沙棘不断改变分株的克隆生长型。在种群增长和稳定阶段，分株以合轴型为主;在种 群衰退阶段，分株以单轴型为主;在林窗更新阶段，分株又以合轴型为主。分株克隆生长型的这种 循环变化过程，是中国沙棘有效利用环境资源和维持种群稳定性的对策之一

Dynamics on the Clonal Growth of Ramets of Hippophae rhamniodes L. subsp sinensis Population

Ramets in the population of Hippophae rhamniodes L. subsp sinensis can be classified by single axes and complex axes， the differences of numbers and proportion of them within a population reflex some ecological adaptation significances. In order to understand the transformation laws of clonal growth form with the increase of population age， the time dynamic of clonal growth form was studied by using the method of spatial series substitution for time series and plots arranged with age. The results showed that the clonal growth form changed continuously by the birth and death regulation of daughter ramet and tillˉ er. At the stage of population increase and population stabilization， the population was dominated by the ramets with complex axis. At the stage of population decrease， the population was dominated by the raˉ mets with single axis. And at the stage of gap regeneration， the population again was dominated by the raˉ mets with complex axis. Such a periodical transformation of clonal growth form is one of the strategies to make full use of environmental resources and maintain the stability of clonal population.