高原鼠兔对垂穗披碱草及豆科植物生长特性的影响

高原鼠兔通过取食对高寒草甸产生广泛的影响，从而影响高寒草甸植物的个体生长特征。2012年在青海省果洛州矮嵩草草甸，以高原鼠兔喜食植物(豆科和垂穗披碱草)为研究对象，通过小区控制研究高原鼠兔取食（对照组、低密度处理组、中密度处理组、高密度处理组）对植物个体生长特征的影响。研究显示：在实验前期（5月和6月），喜食植物个体特征基本上无明显规律；在实验后期（7月和8月），随着高原鼠兔取食强度增大，高原鼠兔喜食植物的地上生物量、平均高度、分蘖枝数、分蘖枝长度、丛幅均呈下降趋势；叶片长度和叶片数均呈先上升后下降态势。2.高原鼠兔喜食植物个体特征的增长率对照组显著高于高密度处理组（P<0.05）。以上结果表明(1)高寒草甸豆类植物在其生长后期与高原鼠兔的取食强度呈一定的负相关关系；高原鼠兔取食强度在阈值（中、低密度）内有利于垂穗披碱草的生长，但超过其阈值的取食强度不利于其生长。(2)高原鼠兔高强度的取食对其喜食植物个体的生长率有明显的抑制作用。

Impact of plateau pikas（Ochotona curzoniae）on Elymus nutans and legume plant physiological properties in alpine meadow

Activities of plateau pikas（Ochotona curzoniae）affect physiological properties of different plant in alpine meadow communities by foraging. A controled experiment was conducted to determine the effects of disturbance by plateau pikas on physiological properties of legume and Elymus nutans from 2010 to 2012 in Guoluo, Qinghai province. The results showed that（1）There were no significance differences among the treatments in May and June: the aboveground biomass, plant height, tillers number, tillers length, canopy coverage all decreased, but the lengths and the number of Elymus nutans leafs all increased initially, and then decreased with increased disturbance levels by plateau pika foraging in July and August.（2）The increasing range of plants which were preferred by plateau pikas in control（CK）was significantly higher than that in high density areas（HD）(P<0.05). Plateau pika foraging intensity showed a negative correlation during legume late growth stage. The foraging intensity in the low or medium densities is favorable to Elymus nutans leaf growth, but greater feeding intensity is unfavorable to its growth.（ii）Higher plateau pika foraging intensity has obvious inhibitory effects on the increasing range of plants which were preferred by plateau pikas.