冷蒿种群在不同放牧强度胁迫下构件的变化规律

在中国科学院草原生态系统定位研究站的羊草草原放牧退化系列上，选定无放牧（已围栏保护了20a的羊草样地）、轻度放牧、中度放牧、重度放牧的不同牧压梯度地段，采用样方法调查冷蒿的构件数量特征。结果表明冷蒿的营养枝数、不定根数、匍匐茎长在4个梯度上均有显著差异，而且都随牧压增大而增加，但不定根间的平均距离（匍匐茎长/不定根数）与营养枝数/不定根数两项却不随牧压变化而变化。就生物量而言，各构件干重在4个梯度间也有显著差异，而且随牧压增大而增加。在相应梯度上所做的25cm×25cm×10cm土体根量数据亦有相似的规律。

Variation of module of Artemisia frigida population under different grazing intensities

The quantities of modulus of Artemisia frigida populations were sampled in the series of grazing gradient with no grazing (having been protected for twenty years by pen), mild grazing , moderate grazing , and heavy grazing in a Leymus chinensis grassland near the Inner Mongolia Grassland Ecosystem Research Station. The results are as follows: along this gradient, Artemisia frigida individuals hada significant difference in quantities of vegetative tillers , quantities of adventitio...