【摘要】 为了探讨不同退化程度高寒草甸的土壤性能的变化以及草甸退化与土壤退化的关系,采用常规测定方法对不同退化程度(原生植被、轻度退化、中度退化、重度退化和黑土滩)高寒草甸的土壤理化性质以及酶活性进行测定,并采用主成分分析对5种不同退化程度高寒草甸的13个土壤特性进行分析及综合评价。结果表明,5种不同程度退化草地的土壤含水量、土壤有机质、全氮、全磷、速效磷和速效钾等指标均表现为0-10 cm土层大于10-20 cm土层。在0-10 cm土层中,随着退化程度的加重,土壤含水量、土壤有机质、全氮以及速磷呈下降趋势,且原生草地和轻度退化草地显著高于中度退化、重度退化和黑土滩(P<0.05);在10-20cm土层中,土壤pH值、硝态氮、全钾等含量随退化程度的增加呈上升趋势,土壤含水量、土壤有机质、全氮、铵态氮、全磷、速效磷以及速效钾含量随退化程度的增加呈下降趋势。不同程度退化草地的土壤脲酶随着土层深度的增加而增加,中性磷酸酶和蔗糖酶随着土层深度的增加而减少。脲酶活性在0-10 cm土层随着退化程度的加剧有增加的趋势,而中性磷酸酶和蔗糖酶活性均有降低趋势。在10-20 cm土层中,脲酶活性表现为原生与中度退化显著高于重度退化、轻度退化和黑土滩(P<0.05);中性磷酸酶活性是中度退化除与原生草地差异不显著外,与其他草地差异显著(P<0.05);轻度退化草地的蔗糖酶活性最高,中度退化草地的蔗糖酶活性显著低于其余4种退化草地(P<0.05)。通过主成分分析得知,在0-10 cm土层中,综合评分排列顺序为轻度退化>原生>重度退化>黑土滩>中度退化;在10-20 cm土层中,不同退化草地排列顺序为原生>轻度退化>中度退化>黑土滩>重度退化。以上结果表明,高寒草甸的退化与土壤的退化关系密切,这为高寒草甸的合理利用和恢复提供了理论依据。更多还原

【Abstract】 In order to explore the changes in soil properties and the relationship between meadow degradation and soil degradation of alpine meadows with different degrees of degradation, the soil physical and chemical properties and enzyme activities of alpine meadows with different degrees of degradation(primary vegetation, light degradation, moderate degradation, severe degradation and black soil beach) were measured in this study by conventional soil physical and chemical properties determination method, and analyze and comprehensively evaluate 13 soil characteristics of 5 alpine meadows with different degrees of degradation by principal component analysis. The results showed that 0-10 cm soil layer was larger than 10-20 cm soil layer of soil water content, soil organic matter, total nitrogen, total phosphorus, available phosphorus and available potassium of different degrees of degraded grassland. With the increase of degradation degree, soil water content, soil organic matter, total nitrogen and available phosphorus showed a downward trend, and primary vegetation and light degradation were significantly higher than moderate degradation, severe degradation and black soil beach in 0-10 cm soil layer(P<0.05). In the soil layer of 10-20 cm, the p H, NO3--N, total potassium increased with the increase of degradation degree, Soil water content, soil organic matter, total nitrogen, NH4+-N, total phosphorus,available phosphorus and available potassium decreased with the increase of degradation degree. The soil urease of different degrees of degraded grassland increased with the increase of soil depth, and the neutral phosphatase and sucrase decreased with the increase of soil depth. The urease activity increased with the degree of degradation, while the activity of the neutral phosphatase and sucrase decreased in 0-10 cm soil layer. In the soil layer of 10-20 cm, the urease activity of primary vegetation and moderate degradation was significantly higher than severe degradation, light degradation and black soil beach was significant(P<0.05). The neutral phosphatase activity of the moderate degradation was significantly different from the other grasslands except for the primary vegetation(P<0.05). The sucrase activity of light degradation was the highest, and moderate degradation was significantly lower than that of the other four degraded grasslands(P<0.05). According to principal component analysis, the sequence of the comprehensive scores was light degradation>primary vegetation>severe degradation>black soil beach>moderate degradation. In the 10-20 soil layers, the sequence of the comprehensive scores was primary vegetation>light degradation>moderate degradation>black soil beach>severe degradation. The above results indicate that the degradation of alpine meadow is closely related to soil degradation,which provides theoretical basis for the rational utilization and restoration of alpine meadows.更多还原