贺兰山低山区土壤理化性状与其酶活性空间变化特征

Spatial Variations in Soil Physicochemical Properties and Enzyme Activities in the Low Mountain Area of Helan Mountain

贺兰山低山区干旱少雨,植被稀疏,地表剥蚀严重,生态环境极为脆弱。本文对贺兰山低山区5个海拔高度的表层土壤理化性状、4种常见土壤酶活性及其相关关系进行了研究。结果表明:(1)随着海拔高度的增加,土壤水分含量和总孔隙度呈上升趋势,容重、有机质和速效磷呈下降趋势,TC、TN和碱解氮呈现先降低后升高的变化趋势,碳氮比呈先升高后降低的变化趋势;(2)随着海拔升高,土壤脲酶和碱性磷酸酶活性呈先降低后升高的变化趋势,蔗糖酶和过氧化氢酶呈上升趋势;(3)脲酶活性和磷酸酶活性与土壤全氮呈显著正相关(P<0.05)。研究表明,不同海拔高度表层土壤理化性状各指标、酶活性均存在差异性,且土壤理化性状与酶活性之间相互影响。

The low mountainous area of Helan Mountain has sparse vegetation,severe surface erosion and a fragile ecological environment.In this study,we analyzed surface soils at five different altitudes in the low moun-tainous area of Helan Mountain to determine their basic physical and chemical properties.the activities of four common soil enzymes and their correlations.The results showed that with increasing altitude,the soil moisture content and total porosity showed upward trends,while bulk density,organic matter and available phosphorus showed downward trends,and TC,TN and alkali-hydrolyzed nitrogen showed trends that were first decreasing and then increasing.As the altitude increased,the carbon-nitrogen ratio increased and showed a trend of first increas-ing and then decreasing,while soil urease and alkaline phosphatase activities showed the opposite trends that were first decreasing and then increasing,and sucrase and catalase showed steadily increasing trends.Urease activity and phosphatase activity were significantly positively correlated with soil total nitrogen.Previous studies had also found differences in various physical and chemical property indexes and enzyme activities of surface soil at different altitudes,and that the physical and chemical properties of soil and enzyme activities affect each other.