高原鼠兔对高寒草甸土壤有机质及湿度的作用

为探讨高原鼠兔对土壤理化性质的作用,本研究于2005年8月,采用灼烧和烘干法,分别测定了高原鼠兔栖息及被灭杀地区土壤有机质含量及湿度。结果表明:高原鼠兔栖息地区,0～5cm及6～10cm土壤层有机质含量和湿度均极显著或显著高于被灭杀地区;11～30cm土壤层,二者无显著的差异;31～50cm土壤层,有机质含量差异极显著,而土壤湿度则无显著差异。说明,高原鼠兔活动可增加高寒草甸土壤表层有机质含量和湿度,进而改变土壤理化性质,促进生态系统物质循环。

Impacts of plateau pikas on soil organic matter and moisture content in alpine meadow

We investigated the impact of plateau pikas(Ochotona curzoniae)on the organic content and moisture content of soil in alpine meadow.Soil samples were collected in late summer 2005 from layers up to 50 cm deep from an area where pikas were at a density of ca.50 ha-1(medium density)and from an area where no pikas were present following intensive control 18 years ago.The amount of organic matter in the soil was determined by mass loss on ignition(% by weight).Soil moisture content was determined by mass loss following drying(% by weight).In the top 10 cm of soil there was more organic matter and a higher moisture content in areas where pikas were present than where they were absent(organic matter ca.23.20% vs.ca.17.05% and ca.17.28% vs.ca.15.35%;moisture content ca.54.05% vs.ca.41.03% and ca.44.48% vs.ca.39.49%).Between 11-30 cm deep,both areas had similar soil organic matter(average ca.15.35%;ca.14.44% and ca.13.55%)and water content(average ca.39.15%;ca.37.60% and ca.34.00%).Between 31-50 cm deep there was more organic matter(ca.13.74%)in areas where pikas were present than where they were absent(ca.12.83%),but both areas had similar soil moisture content(average ca.30.40%).Our results show that medium densities of plateau pikas can promote the material cycle in alpine meadow ecosystems.