玛曲高寒沙化草地不同灌木根际微量元素含量特征

选取玛曲县高寒沙化草地3种不同灌木山生柳(Salix oritrepha)、紫穗槐(Amorpha fruticosa)和沙棘(Hippophae rhamnoides)，研究其根际与非根际土壤微量元素（Fe、Mn、Cu、Zn）含量特征及土壤pH值的变化。结果表明，1)3种灌木的根际pH值均低于非根际，表现出不同程度的酸化作用。2)3种灌木根际全量铁、铜均高于非根际，紫穗槐和沙棘富集明显，而全量铜只有紫穗槐富集明显；除山生柳外，其余2种灌木根际全量锰含量均低于非根际；沙棘根际全量锌含量高于非根际，其余2种灌木均为根际低于非根际。3)紫穗槐的根际有效铁高于非根际，其他2种均低于非根际，紫穗槐的富集率最高，为 29.81%；除山生柳外，其他2种灌木根际有效锰含量均高于非根际；有效锌的富集趋势与有效铜相似，依次为沙棘>山生柳>紫穗槐。4)根际及非根际土壤各养分性状之间，存在一定的相关性。在根际土壤中，铜的全量和其有效量呈显著正相关性；全量铁和铜全量、有效量之间表现出了极显著正相关关系；铁和锰的有效量之间呈极显著正相关关系。在非根际土壤中，铜和铁的全量之间呈极显著正相关关系。

The character of microelement contents among different shrubs rhizosphere at the desertification alpine grassland in the Maqu County

Salix oritrepha，Hippophae rhamnoides and Amorpha fruticosa growing in the desertification alpine grassland in the Maqu County were selected to exam the differences of soil microelement and pH value between rhizosphere and no rhizosphere. The results of this study indicated that the soil pH values of rhizosphere were significantly lower than that of no rhizosphere for three shrubs, and they showed a different degree of soil acidification. The total Fe and Cu contents of rhizosphere were significantly higher than that of no rhizosphere for three shrubs, in which H. rhamnoides and A. fruticosa significantly enriched the Fe, and Amorpha enriched the Cu. Except for S. oritrepha, the total Mn content of rhizosphere in other two shrubs was lower than that of no rhizosphere. The total Zn content of H. rhamnoides at rhizosphere was higher than that at no rhizosphere, while other two species had a higher Zn content in no rhizosphere than that in rhizospheres. The available Fe content of A. fruticosa at rhizosphere was higher than that at no rhizosphere, however, other two species were lower. The enrichment trend of available Zn was H.rhamnoides>S.oritrepha>A.fruticosa. These results suggested that there was a correlation relationship on soil nutrient conditions between rhizospheres and no rhizospheres. In the rhizosphere, the total Cu content was positively related to the available Cu content and the total Fe content was positively related to the total Cu and the available Fe content. The available Fe content was positive related to the available Mn content. In the no rhizosphere, the total Fe content was positive correlation with the total Cu content.