草原退化过程中土壤碳氮分布与群落生物量的关系

The Relationship Between Soil Organic Carbon and Nitrogen Distribution and Community Biomass in the Process of Grassland Degradation

为了有效开发利用草原、维护草原生态系统良性循环,以内蒙古呼伦贝尔克鲁伦流域的克氏针茅(Stipa krylovii)典型草原为研究对象,通过设置不同放牧强度的天然草原试验样地,采用野外实地调查与室内分析法,研究不同放牧强度下土壤碳-氮空间分布格局以及其对植被生产力的影响。结果表明:不同放牧梯度上植物地上生物量变化趋势为:轻牧>中牧>重牧;不同放牧梯度上的土壤有机质碳含量有显著差异性,变化表现为:轻牧>重牧>中牧;不同放牧梯度上的土壤氮含量有显著差异性,且轻牧>重牧、轻牧>中牧,中牧、重牧变化关系不显著;不同放牧梯度上,土壤C/N值与植物生物量均保持一种相对稳定的关系。

For effective development and utilization of grassland ,maintenance of grassland ecosystem virtuous circle ,taking the Hulunbeir Kerulen＆#39;s esparto（Stipa krylovii）typical grassland in Inner Mongolia as research object ,setting up different grazing gradients of natural grassland test sample plot and using the methods of field investigation and indoor analysis ,different grazing intensity of soil carbon -nitrogen space step pattern and its influence on vegetation productivity were studied .The results showed that the plant biomass changed with the trend of lightly grazed＆gt; moderately grazed＆gt; heavily grazed in different grazing gradients ;Soil organic carbon content had obvious difference ：lightly grazed＆gt; heavily grazed＆gt; moderately grazed ;Soil nitrogen content had obvious differences between various samples in different grazing gradients ：lightly grazed＆gt; heavily grazed and lightly grazed＆gt;moderately grazed ,the relationship between moderately grazed and heavily grazed was not obvi-ous ;soil C/N value and plant biomass all maintained a relatively stable relation in different grazing gradients .