毛乌素沙地南缘不同植被恢复类型的土壤养分效应

摘要

In order to explore effects of vegetation on nutrients in soils, nutrients characters of soils under natural grass, closed grass, abandoned lands, forest lands returned from farmlands and fixed sandy areas in Mu Us Desert were researched. The results indicated that vegetations in varied types have different effects on organic matter, total N, available N and available P, among which the first three were all higher in soils under closed grass, forest lands returned from farmlands, and fixed sandy lands than those under natural grass and abandoned lands. This was totally contrary with contents of available P in soil. In addition, nutrients in soils at 0-20 cm were more influenced by vegetation, than those at 20-60 cm, and Caragana Korshinskii proved better in improving nutrients in soils.%为了探讨植被恢复对土壤养分的影响，研究了毛乌素沙地南缘天然草地、人工封育草地、撂荒地、退耕还林地、固定沙地5种不同植被恢复类型区的土壤养分特征。结果表明：不同植被恢复类型对土壤有机质、全氮、有效氮、速效磷的影响存在明显差异；灌草结合的人工封育草地、退耕还林地、固定沙地土壤有机质、全氮、有效氮的含量高于以草本为主的天然草地和撂荒地，但土壤速效磷的含量刚好相反；植被对表层0～20cm土壤养分的影响大于下层20～60cm土壤，植被作用下土壤养分向表层富集；采用柠条进行退耕还林，能够充分发挥其根系特性，有利于改良深层土壤养分。