贺兰山西坡不同类型草地土壤酶活性特征

Characteristics of Soil Enzyme Activities in Different Grasslands in the Western Slope of the Helan Mountain,China

以阿拉善左旗境内贺兰山中段(西坡)山前地带的主要草地类型为对象,分析不同类型草地土壤酶活性的分布特征,及其与气候、植被和土壤等环境因子的关系。结果表明:①随着海拔高度的降低,土壤脲酶、蔗糖酶、碱性磷酸酶和过氧化氢酶活性表现为:高山草甸>山地草原>山地荒漠草原>草原化荒漠,且在0～10 cm土层的差异尤其显著;②各类草地土壤酶活性均沿土壤垂直剖面依次降低,差异呈显著性水平;③偏相关及逐步回归分析表明,影响该区草地土壤脲酶和蔗糖酶活性最主要的因素为土壤微生物碳氮、有机碳和全氮,碱性磷酸酶主要受土壤微生物碳和全氮影响,对过氧化氢酶影响最大的因子为土壤微生物碳、pH、全氮和降水量。

Soil enzymes are the specific biological catalysts for biochemical reaction in soil, and one of the indica-tors of evaluating soil health. This study was conducted at the grasslands in the westem slope of the Helan Mountain and its piedmont in Alxa, Inner Mongolia, China. With measuring the distribution characteristics of soil enzyme ac-tivities, the relationships between soil enzyme activities and soil, vegetation and climatic factors were studied. The results are as follows ： （ 1 ） Soil enzyme activities were decreased with the decrease of altitude and in an order of al-pine meadow 〉 mountain steppe 〉 mountain desert steppe 〉 steppe desert, and the difference was significant in topsoil （0-10 cm in depth） ; （2） Soil enzyme activities were decreased with the increase of soil depth; （3） Ac-cording to the partial correlation and stepwise regression analysis, the main factors affecting the activities of soil ure-ase and saccharase were soil microbial biomass carbon, soil organic carbon and total nitrogen, soil alkaline phos-phatase activity was mainly affected by soil microbial biomass carbon and total nitrogen, and soil catalase activity was mainly affected by soil microbial biomass, total nitrogen, pH value and precipitation.