木本克隆植物中国沙棘种群林缘扩散规律研究

通过对中国沙棘林缘扩散过程和规律进行分析,揭示了中国沙棘的克隆生长过程.结果显示:中国沙棘以年龄最大的分株为中心向两侧实施克隆扩散,形成中间分株大、密度小以及越向两侧分株越小、密度越大的双向“阶梯式”种群外貌.然而,种群向两侧的扩散并不对称,其原因在于扩散过程受到土壤水分状况的影响.向土壤水分条件较好的一侧,林缘扩散种群以分株较大、密度较高为特征,克隆生长格局倾向于“聚集型”;向土壤水分较差的一侧,林缘扩散种群以分株较小、密度较低为特征,克隆生长格局倾向于“游击型”.由此表明在不同的土壤水分状况下,中国沙棘通过克隆生长调节形成与之相适应的克隆生长格局,即觅养对策.

The edge dispersal regulation of the population of clonal tree species Hippophae rhamniodes ssp. sinensis

In order to understand the growth process of clone plants, the dynamics and regulations edge dispersal of the clone population of Hippophae rhamniodes ssp. sinensis was studied.The results showed that the Hippophae rhamniodes ssp. sinensis spread along two sides with the eldest ramets in the center in terms of clone-proliferation, which formed a "bidirectional stepped population", with bigger ramets and low density in the center, and smaller ramets and higher density outside.However, the dispersal process to both sides was asymmetric, which was infiuenced by soil moisture.By the side with better soil moisture condition, the edge dispersal populations had bigger ramets with higher density, the clonal growth tended to "aggregated distribution pattern";otherwise, the edge dispersal populations showed smaller ramets with lower density, the clonal growth tended to "guerrilla pattern".It indicated that under different moisture conditions, Hippophae rhamniodes ssp. sinensis formed different but appropriate clonal growth pattens, foraging strategies.