毛乌素沙地飞播造林植被恢复过程土壤酶活性的变化

以内蒙古自治区毛乌素沙地飞播造林地为对象，研究了不同植被恢复年限样地土壤酶活性的变化。结果表明:经过17 a的植被恢复，土壤表层（0—10 cm）脲酶、蔗糖酶和磷酸酶显著增加，土壤过氧化氢酶活性在植被恢复初期上升趋势明显；土壤脲酶、蔗糖酶和磷酸酶活性与土壤养分之间有一定的正相关性，而这种相关性在土壤表层（0—10 cm）中要强于中下层（10—40 cm）；土壤表层（0—10 cm）土壤脲酶、蔗糖酶和磷酸酶三种水解酶之间呈极显著相关（p < 0.01）。表明毛乌素沙地飞播造林植被恢复过程中土壤脲酶、蔗糖酶和磷酸酶活性的增强和土壤养分的改善相互促进，土壤酶活性能在一定程度上能反映沙地植被恢复过程中土壤肥力水平，沙地表层土壤中氮素的转化、多糖的转化和有机磷的转化之间关系密切并且相互影响。

Changes of Soil Enzyme Activities in Mu Us Sandy Land with Aerial Seeding Afforestation

The soil enzyme activities in different vegetation restoration periods by aerial seeding afforestation in Mu Us sandy land of Inner Mongolia Autonomous Region were studied. The results revealed that soil urease, sucrase and phosphatase activities increased remarkably after 17 years of revegetation, and soil catalase activity increased at the early stage of vegetation restoration. At the same time, soil urease, sucrase and phosphatase enzyme activities showed stronger correlations with soil nutrients, while this correlation in the surface soil (0—10 cm) is stronger than in the lower layer (10—40 cm). In addition, there was a highly significant correlation among soil urease, soil invertase and soil phosphatase activities (p < 0.01) of surface soil (0—10 cm). These indicated that in the process of vegetation restoration, soil urease, invertase, phosphatase activities and soil nutrient promoted each other due to afforestation in Mu Us Sand land by aerial seeding. This result showed soil enzyme activity could reflect soil nutrient in the process of vegetation restoration. Indeed, there was a close relationship between the transformation of nitrogen, polysaccharide and organic phosphorus in the surface soil.