鼢鼠的造丘活动及不同休牧方式对草地植被生产力的影响

研究表明,高原鼢鼠的造丘活动在停止放牧扰动的条件下,对于过牧型退化草地而言,非但不会对草地生产力造成破坏,相反,在植被高度、植被组成和产草量等生产力构件上均表现出了显著的促进作用。在相同的休牧条件下,鼢鼠分布地植被性状的各项指标除植物多样性低于无鼢鼠分布地外,其余指标均极显著高于无鼢鼠分布地(P<0.01),其中丘缘地又极显著地高于丘间地(P<0.01);在同为3年的三种休牧方式中,实施绝对禁牧的方式最佳,其次为降低载牧量50%且于返青至6月前禁牧的方式,这两种休牧方式均可较好地满足鼠丘在退化草地植被恢复过程中充分发挥其生态功能所必需的外部条件。

Effects of mound-building activity of zokor(Myospalax baileyi) and different regimes of grazing-prohibited on vegetation productivity

A three-year study was conducted in a degraded pasture caused by over-grazing to investigate the effects of mound-building activity of zokor and grazing-prohibited regimes (non-grazed) on the productivity of vegetation community. The results indicated that the mound-building activity of zokor showed significantly facilitation effects on vegetation height, composition and productivity ( P <0.01) under the condition of non-grazing in the over-grazed pasture. The indices of vegetation, except for diversity index, were significantly higher in the site with zokor activity than that of without zokor activity under the same condition of grazing-prohibited, among which the indices around-mound were highly significantly greater than that of between-mound ( P <0.01). In the three grazing-prohibited regimes the effects of completely grazing-prohibited regime were the best, then were the regime of 50% utilization rate which was grazing-prohibited from April to June. These two regimes of grazing could provide better external conditions for zokor mound to exert its ecological function during the period of vegetation restoration.