为研究毛乌素沙地丘间低地主要植物群落在不同土壤环境下土壤酶活性的变化以及土壤酶活性与土壤理化因子之间的关系,本文对毛乌素沙地丘间低地的6类主要植物群落类型的14种土壤理化因子和4种土壤酶(过氧化氢酶、脲酶、多酚氧化酶、转化酶)活性进行了测定,并对不同植物群落之间土壤酶活性的差异以及土壤酶活性与土壤理化因子间的相关性进行了分析。结果表明:(1)寸草苔群落和碱茅群落的过氧化氢酶活性显著高于北沙柳灌丛和芦苇群落;各群落之间脲酶活性不存在显著性差异;碱茅群落和假苇拂子茅群落的多酚氧化酶活性显著高于其他群落;北沙柳灌丛、芦苇群落和寸草苔群落的转化酶活性显著高于尖被灯心草群落。(2)4个土壤酶活性之间只有转化酶和多酚氧化酶活性呈显著负相关,而其他酶活性之间并不存在显著相关关系。(3)与过氧化氢酶活性显著相关的土壤理化因子有HCO3-、Cl-、K+、Na+、土壤全磷含量以及p H;与脲酶活性显著相关的土壤理化因子有p H;与多酚氧化酶活性显著相关的理化因子有HCO3-、Ca2+、土壤全氮、全碳、有机碳含量以及p H;与转化酶活性显著相关的理化因子有土壤容重和土壤有机碳含量。总之,毛乌素沙地丘间低地主要植物群落的土壤酶活性受到植物群落类型和土壤理化因子的共同影响。 In order to study the changes of soil enzyme activities and the relationship between soil enzymatic activities and soil physico-chemical factors in the lowland inter-mound of Mu Us Sandland in different soil environments, 14 soil physico-chemical factors and 4 soil enzymes (catalase, urease, polyphenol oxidase and invertase) were measured. The differences of soil enzyme activities and soil enzyme activities between different plant communities and soil physicochemical The correlation between factors was analyzed. The results showed that: (1) catalase (CAT) activity was significantly higher in Salix psammophila community and P. maxima community than those in Salix psammophila and Phragmites australis communities. There was no significant difference in urease activity between communities. Polyphenol oxidase activity in C. lanceolata community was significantly higher than that in other communities. Invertase activity in P. euphratica community, Phragmites communis community and P. septempunctata community was significantly higher than that in A. przewalskii community. (2) There was a significant negative correlation between invertase and polyphenol oxidase activities among the four soil enzyme activities, but no significant correlation was found between other enzyme activities. (3) HCO3-, Cl-, K +, Na +, soil total phosphorus content and p H were significantly correlated with catalase activity. Soil physical and chemical factors significantly correlated with urease activity were p H; and polyphenol HCO3-, Ca2 +, soil total nitrogen, total carbon, organic carbon and p H were significantly correlated with oxidase activity. Soil physico-chemical factors significantly correlated with invertase activity were soil bulk density and soil organic carbon content. In conclusion, the soil enzyme activities of the main plant communities in the lowland Muqusu Sandy Land are influenced by both the plant community type and soil physico-chemical factors.