【摘要】 本文针对中国海北定位站高山草甸土壤不同放牧强度下土壤有机质组分变化进行了分析。实验结果表明 ,藏羊的放牧强度分别为 8,4,2 ,0只 hm2 的情况下 ,从 1998— 2 0 0 1年连续放牧 4年间 ,土壤有机质各组分不论是重量还是各组分有机质含量上都有明显变化。最大放牧强度于对照相比 ,G0 组的重量百分比和有机碳含量分别下降 1 2 4% ,1 0 12 % ;而G1 组则下降 0 4% ,1 42 2 % ;G2 组下降 1 4% ,0 5 0 0 %。轻度放牧组有机质组分的重量百分比和有机质含量分别下降 4 0 4% ,0 3 3 %。强度放牧导致土壤肥力下降 ,草场退化 ,生态环境遭到破坏更多还原

【Abstract】 The fraction change of soil organic substance of alpine meadow in Hai bei grazing fixed station of Qinghai,China,were analyzed under different grazing intensity.The results showed:when the grazing intensities were 8,4,2,0 Tibetan sheeps per hm~2,the weight and content of each fraction of soil organic substance all changed obviously under the condition of four years of continuous grazing(1998—2001).The comparation results of heaviest grazing group with the controlled group indicated that weight percentage and organic carbon content of G 0 group decreased 1.24% and 1.012%,while those of G 1 group and G 2 group decreased 0.4%,1.422% and 1.4%,0.500%,respectively.For the light grazing group,weight percentage of fraction of organic substance and organic substance content decreased 4.04% and 0.33%.Heavy grazing leaded to a dropping of soil fertility,regressive of rangeland and destroy of eco-environment.更多还原