高原鼠兔对小嵩草草甸的破坏及其防治

1997～ 2 0 0 0年在青海省果洛州达日县 ,通过测定不同程度退化草地、人工草地和除杂草地中高原鼠兔种群数量的变化以及对草地的破坏程度 ,分析了草地植物群落变化对高原鼠兔种群数量的影响。结果表明 :随草地退化程度的加重 ,高原鼠兔种群数量相应升高 ,重度退化草地中高原鼠兔种群数量降低 ,是由食物资源不足引起。不同程度退化草地之间高原鼠兔种群数量差异极显著 (t未退化与轻度 =2 5 36 97,t未退化与中度 =2 5 5 5 ,t未退化与重度 =36 4 0 6 0 ,t轻度与中度 =2 3 2 794 ,t轻度与重度 =14 3439,t中度与重度 =2 0 1785 ,df =3,p<0 0 0 1)。高原鼠兔对草地的破坏面积与平均单坑面积呈显著的相关关系 (F =2 2 0 4 6 ,df=3,P <0 0 0 1)。在草地达到重度退化以前 ,高原鼠兔的种群密度升高 ,对草地的危害则加重。草地植物群落空间结构的变化直接影响高原鼠兔的种群数量 ,当植物群落高度增加时 ,其种群数量开始减少 ,反之则增加。

Studies on Destruction, Prevention and Control of Plateau Pikas in Kobresia pygmaea Meadow

This paper studied effects of various p lateau pika population sizes in different levels of degraded grasslands, planted grassland and weeds control treatment, and analyzed the response of plateau pikas to envir onmental changes The results indicated that plateau pika population sizes increased with the degrees of grassland deterioration Population sizes of pla teau pika were relative low in heavily degraded grassland because of limited f ood resource Population sizes sho w significant differences among different treatments of non degraded grassland ( NDG), lightly degraded grassland (LDG), moderately degraded grassland (MDG), and heavily degraded grassland (HDG),i e , ( t NDG-LDG = 25 36 9 7, t NDG-MDG = 25 55, t NDG-HDG = 3 6 406 0, t LDG-MDG =23 279 4, t LDG-HD G = 14 343 9,and t MDG-HDG = 20 178 5, df =3, P <0 001).Areas destroyed by plateau pik as had significantly positive correlation with area per hollow ( F =220 46, df =3, P <0 001).Be fore grassland became heavily degraded grassland, the degree of degradation aggr avate when population sizes increased.The changes of the spatial structur e of plant community could cause the changes of population sizes of plateau pika Population sizes were decreased when height and coverage of plant commun ity were reduced