大兴安岭森林草原过渡带白桦及主要草本植物生态位关系的研究

以白桦、日阴菅及其它主要草本植物的个体数量为指标，分析了各植物种群在土壤有机质，速效P和pH值3个资源维上的生态位宽度和生态位重叠及其在不同海拔条件下的变化规律。日阴菅生态位宽度随海拔升高而增大，其余植物种类在有机质资源维上的生态位宽度，大都是以中等海拔（800m)的样带最宽，而在速效P资源维上，又以中等海拔的样带为最窄，由于高海拔及相应低气温在某种程度上限制了植物种群在土壤有机质和速效P的利用，主要植物种对之间在这两个资源维上的生态位重叠以高海拔（950m)样带为最小，在土壤pH值资源维上，溪荪与其它主要植物种间的生态位重叠皆以低海拔（650m)样带为最小，可能是其特殊的环境组合迫使溪荪发生了生态位移动，大多数种对在土壤有机质，速效P和pH值3个资源维上都以海拔800m的样带生态位重叠最大。

Niche relationships between Betula platyphylla and main understory herbages in forest-steppe ecotone of Daxingan-ling Mountains.

Niche breadths and overlaps for Betula platyphylla and other main herbaceous plant populations, and their changes along with three soil factor dimensions at three different altitudes were analyzed. The niche breadth of Carex pediformis increased with altitude, and that of other plant species was the widest on t he transect of middle altitude (800m) on the soil organic matter dimension, whil e the narrowest on the available phosphorus dimension. Niche overlaps of most sp ecies pairs on organic matter and available soil phosphorus dimension were the s mallest on the highest altitude (950mabstract On pH value dimension, niche overlaps of Iris sanguinea with most other plant species were the smallest on the lowes t elevation (650m) because of its probable niche shift forced by the special env ironmental complex of altitude. Most of the plant species pairs had the biggest niche overlaps on all the three dimensions on the transect of middle elevation.