毛乌素沙地东南缘沙漠化过程中土壤酶活性的演变研究

研究了毛乌素沙地东南缘沙漠化过程中土壤脲酶、过氧化氢酶和多酚氧化酶活性的响应过程，并对其与土壤养分的相关关系进行分析。结果表明，随沙漠化程度的加剧，土壤脲酶、过氧化氢酶和多酚氧化酶活性均降低，随土层深度的增加，土壤脲酶活性呈降低趋势，土壤过氧化氢酶和多酚氧化酶并未表现出规律性变化，沙漠化过程破坏了土壤酶的活性，三种酶活性能较为敏感地反映土壤环境的变化；相关性分析结果显示，土壤三种酶活性之间存在着极显著正相关性．且三种酶活性与土壤有机质和全氮含量之间同样存在极显著正相关性，表明三种酶在相互作用过程存在共生关系，且能够作为衡量土壤肥力的重要指标。土壤脲酶、过氧化氢酶和多酚氧化酶活性变化可作为衡量沙漠化环境变化的重要指示性指标，并可为进一步揭示沙漠化的生物学规律提供依据。

Study on the evolution of soil enzyme activities in different desertification stages on the Southeastern Edge of Mu Us Sandy Land

This study examined the changes in soil enzyme activities in different desertification stages on the Southeastern Edge of Mu Us Sandy Land, China. Specially, soil urease, catalase and polyphenol oxidase activities were tested and analyzed. In addition, the correlation relationship between enzyme activities and between these enzyme activities and the soil organic matter, total nitrogen were also analyzed. The results showed, with the increasing degree of desertification, urease, catalase and polyphenol oxidase activities were decreasing. And with the increase of soil depth, urease activities were decreasing, while catalase and polyphenol oxidase activities were not changing regularly. Soil enzyme activities were destroyed with the increasing degree of desertification, and could sensitively represent the desertification degree. The results of correlation analysis showed, there were significant correlation between soil urease, catalase and polyphenol oxidase activities, and there were significant correlation between enzyme activities and the soil organic matter, total nitrogen. Urease, catalase and polyphenol oxidase activities interacted in a symbiotic relationship, and could indicate the changing environment of desertification and provide scientific basis for revealing biological law of desertification.