新疆巴音布鲁克草原不同退化程度对土壤特性影响

以高寒草原巴音布鲁克草原为研究对象,通过对不同类型草场的草地利用方式、土壤退化程度和植被类型差异的调查,分析不同类型草场退化程度对土壤理化特性的影响,揭示植被和地表特征及草地利用方式对土壤肥力的影响。结果表明:高寒沼泽草场、高寒草原草场的草地利用方式合理,草地未退化,土壤养分含量高,植被状态良好,高寒草甸草场随放牧压力增大,生境退化程度加重,土壤退化程度加大,表现为土壤容重增大,含水率减少,土壤全磷和有机质浓度减少,植被盖度降低;不同类型草场退化程度与土壤容重、pH和水溶性盐浓度呈显著正相关,与含水率、全磷浓度、有机质浓度和植被盖度呈极显著负相关,与植被盖度相关系数高达-0.907,草场退化过程中土壤肥力因子与植被状态呈极显著正相关。

Effects of different degradation degrees on soil characteristics in Bayanbulak Grassland,Xinjiang

Taking alpine steppe Bayanbulak Grassland as a research object, and based on the differentiation of grassland utilization ways, soil degradation degrees and vegetation types of different grasslands, the effects of the grassland degradation degree of different grasslands on soil physical and chemical properties were analyzed, and the effects of vegetation and surface characteristics as well as grassland use patterns on soil fertility revealed. The results showed that alpine marsh grasslands and alpine grasslands were utilized in a reasonable way, the grasslands had not been degraded, the soil nutrient content was high, and the vegetation was in a good state. As to the alpine meadow, the higher the grazing pressure, the worse the habitat degradation and the worse the soil degradation, which was reflected in the increase of soil bulk density, the decrease of soil moisture content, and the decrease of soil total phosphorus and organic matter concentration, resulting in the decrease of vegetation coverage. The degree of grassland degradation of different types was positively correlated with soil bulk density, pH and water-soluble salt concentration, and the correlation was up to a significant level. It had highly significant negative correlation with water content, total phosphorus concentration, organic matter concentration and vegetation coverage, with the correlation coefficient up to -0.907. There was a significant positive correlation between soil fertility factor and vegetation state in the process of grassland degradation.