长白山北坡林线灌木草本植物与岳桦的动态关系

本文以长白山北坡林线为研究区,调查125个样方内岳桦种群的径级结构与林线灌草植物的生态重要值。采用常规统计和聚类方法分析岳桦种群与8种常见灌草植物的动态特点,采用典型与单因子相关分析岳桦动态与林线灌草植物的变化关系。结果表明岳桦种群扩张带动林下灌草的相继移动,林线上侵不仅是单一乔木的变化,而是森林群落向苔原群落的入侵,从空间上挤占生态位的过程。另外,这种替代中各个成分变化也存在差异,由于各种植物在群落中的地位和生态竞争力的区别,在替代过程中不同植物变化也具有明显的异步性。

Dynamics change of Betula ermanii population related to shrub and grass on treeline of northern slope of Changbai Mountains

We selected the treeline of northern slope of Changbai Mountains as study area. The diameter-class structure of Betula ermanii population and ecological important values of shrub and grass were investigated on 125 quadrats. The dynamics changes of Betula ermanii population and 8 plants of shrub and grass were revealed using conventional statistics and hierarchical cluster analysis. The relationship between population dynamics and plants changes was evaluated using correlation analysis. The results showed that population expansion of Betula ermanii drove the shifts of shrub and grass belonged to forest community. Treeline shift was not only tree change, but also forest community invaded tundra community. The ecological niche of tundra community was excluded by forest community. Moreover, the change difference among various compositions was very obvious. The asynchrony appeared during replacement process of varied plants due to the distinction of ecological competitive and status in community.