【摘要】 对阿拉善退化荒漠草地恢复过程中霸王灌丛对土壤肥力的影响进行了研究。结果显示:(1)霸王灌丛对土壤的C、N、P有明显的富集,灌丛下的影响主要发生在0～10cm土层,而灌丛根部对10～20cm的土层也有影响。(2)放牧和围封显著影响着霸王灌丛根部和灌丛下的土壤肥力,土壤有机C、全N、全P均为围封6a>围封2a>自由放牧,pH值为围封6a<围封2a<自由放牧;放牧和围封也显著影响着灌丛根部和灌丛下的土壤养分富集率,土壤有机C、全N、全P的富集率均为围封6a>围封2a>自由放牧。(3)霸王灌丛生物量与灌丛根部、灌丛下土壤有机C、全N和全P的含量呈显著的正相关,与pH值呈显著的负相关,而与灌丛间地的土壤有机C、全N、全P和pH值没有明显的相关关系。更多还原

【Abstract】 The influence of shrubs on soil fertility in the vegetation recovering processes in arid desert steppe of Alxa was studied. Soil chemical properties in different sites of shrub Z. xanthoxylum in enclosure and free-grazing state were measured. For each shrub three different positions were distinguished nearby shrub root, under the canopy and in open land. Soil samples were taken from depths of 0～10 cm and 10～20 cm and were analyzed for C_org, N_total, P_total, and pH(H₂O). The following results have been obtained. ①Chemical properties of soils nearby shrub root and under the canopy were affected significantly by enclosure and grazing. The trend of the concentrations of C, N, and P at the same position of shrubs in different sites were enclosure for six years>enclosure for two years>free grazing. The enrichment ratios of most soil properties nearby root in enclosure areas were significantly higher compared with those in free-grazing areas, especially in 0～10 cm soils. ②Soils nearby root had significantly higher concentrations of C, N and P as well as lower pH value in 0～10 cm and 10～20 cm soils compared with those in open land. Concentrations of C and N in the soils under the canopy increased significantly compared with those in open land. The pH showed only slight but significant differences, but there was no significant difference in P between the soils under shrub canopies and in open land, these effects occurred mainly in surface soil （0～10 cm）. It was proved that shrubs play a vital importance role in the accumulation of nutrients and maintenance of soil fertility following enclosure in arid desert steppe of Alxa.更多还原