内蒙古荒漠草原小针茅群落土壤养分的化学计量学特征

Characteristics of Soil Stoichiometry of Stipa klemenzii Community in Desert Steppe of Inner Mongolia

以内蒙古荒漠草原小针茅群落为研究对象,探索小针茅群落土壤养分化学计量学特征。结果显示:(1)在取样深度0～30cm范围内,随土壤深度增加,二连浩特样地土壤C∶N和C∶P大致呈现先减后增趋势,苏尼特右旗样地大致为增高趋势;两个样地土壤N∶P都表现为先增后减趋势,土壤C∶N∶P均为先减后增趋势。(2)不同样地同一土层间,土壤C∶P和N∶P均为二连浩特样地小于苏尼特右旗样地;C∶N在0～10cm和20～30cm土层为二连浩特样地大于苏尼特右旗样地,10～20cm为二连浩特样地小于苏尼特右旗样地;C∶N∶P均为二连浩特样地大于苏尼特右旗样地。表明土壤C∶N和C∶P在不同样地不同土层间变化趋势不一致,而N∶P和C∶N∶P表现一致;在不同样地同一土层间,二连浩特样地和苏尼特右旗样地土壤C∶P和N∶P与C∶N∶P刚好相反。小针茅群落土壤C∶N平均值(33.43)明显大于全球土壤平均值(13.33),也明显大于我国土壤平均值(10∶1～12∶1),这可能是由于小针茅群落土壤更加缺乏氮素所致。

Taking Stipa klemenzii communities in desert steppe of Inner Mongolia for the object of study,the characteristics of soil stoichiometry of Stipa klemenzii communities were explored.The results showed that：（1） In 0 ～ 30cm depth of soil,C：N and C：P of soil in Erenhot roughly showed the trend of first decreased and then increased,but a broadly increasing tendency in Suniteyou Banner;N：P of soil showed a decreased trend after increasing trend in two samples and C：N：P of soil showed a trend of first decreased and then increased.（2） In the same depth of soil in different sample,C：P and N：P of soil in Erenhot was less than that of Suniteyou Banner;In depth of 0～10cm and 20～30cm,C：N of soil in Erenhot was greater than that of Suniteyou Banner,but it was opposite in depth of 10～20cm,C：N：P of soil in Erenhot was greater than Suniteyou Banner.These indicated that：in different sample and different depth of soil,C：N and C：P of soil were inconsistent,but N：P and C：N：P of soil was consistent;the same depth of soil in different sample,C：P and N：P of soil was opposite with C：N：P of soil in Erenhot and Suniteyou Banner.The average（33.43） of C：N of soil in Stipa klemenzii communities was significantly greater than that（13.33） of Global,and much greater than that（10：1 to 12：1） of China,which may be due to lower nitrogen content of soil in the Stipa klemenzii community.