毛乌素沙地中国沙棘无性系种群林缘扩散规律

以样地调查资料为基础。分析了中国沙棘无性系种群的林缘扩散规律及其生态学意义。结果表明,中国沙棘通过无性系生长向林缘扩散形成“阶梯式”同龄斑块镶嵌体系。群落依靠该体系不断向前移动或者同龄斑声之间的交替更新来维持和恢复其稳定性。同时,林缘扩散种群具有密度大、生产力高等特征,但其生物量积累和自然稀疏过程与有性植物种群具有相同的规律。

The Edge Dispersal Clone Population Regulation of Hippophae rhamnoides subsp. sinensis in the Mu Us Sandland

On the basis of investigated materials in the plot, the dynamics of edge dispersal of Hippophae rhamnoides subsp. sinensis clone population was studied. Edge dispersal was that the clone population continuously invaded the space outside forest and large gaps in the forest by clonal growth and resulted in a "stair shaped" mosaic system of relatively even-aged tree patches which develop in different stages, i. e. with the increasing of distance of the patches from the largest ramet, the mean age and mean height of ramets and population biomass decreased, the population density increased with linear function. The system could move forwards at the speed of 1 m/a or the patches shifted their sites each other, which led to the clone population and maintained its stable state in even large area.