安多县沙漠化过程中土壤理化性质的演变特征

Evolution Characteristics of Soil Properties during Desertification Progress in Amdo County

通过分析安多县不同沙漠化阶段代表性草地土壤的理化性质,揭示了该县草地在沙漠化过程中土壤理化性质的演变特征。研究表明:在沙漠化过程中土壤的理化性质变化明显,从潜在沙漠化向重度沙漠化演变过程中土壤抗风蚀与保水性能下降、土壤pH值升高、土壤颗粒粗化且剖面内土壤颗粒组成分异增大,风蚀对土壤颗粒的机械分选明显;在原始草地演变为潜在沙漠化草地这个阶段有机碳与速效养分损失严重,应重视沙漠化的早期防治。研究结果还表明在沙漠化过程中土壤属性之间存在复杂的相互作用。依据沙漠化过程中土壤理化性质的演变特征,提出了在进行草地恢复时需特别注意的土壤问题。

The problem of soil erosion and desertification in Tibet Plateau has been aggravated due to global warming and human impacts in recent decades. In this study, a case study of Amdo County was carried out using high resolution sampling to investigate how soil properties changed by desertification in Tibet Plateau. The results indicated that soil water retention and soil resistance to wind erosion decreased during the desertification transformation from potential to severe. Meanwhile, soil pH increased dramatically and soil particles become coarse. Nutrient deficiency was a common feature in the desertified grasslands, which should be paid more attention on the early desertification prevention. In addition, some suggestions also were put forward for the vegetation restoration in terms of the soil evolutional characteristics in Tibet Plateau.