武夷山不同海拔典型植被带土壤酶活性特征

Soil enzyme activities in typical vegetation zones along an altitude gradient in Wuyi Mountains

在武夷山自然保护区不同海拔4个典型植被带(常绿阔叶林、针叶林、亚高山矮林以及高山草甸)采集土壤样品,分析了脲酶、蔗糖酶、酸性磷酸酶和过氧化氢酶4种主要土壤酶活性的变化。结果表明:除磷酸酶外,武夷山不同海拔植被带土壤酶活性没有显著的季节差异,磷酸酶活性秋季显著高于其他季节;不同海拔土壤酶活性差异显著,海拔与季节对土壤酶活性无交互影响;土壤酶活性随海拔升高总体上呈上升趋势,高海拔草甸的土壤酶活性显著高于低海拔林地土壤;土壤酶活性具有明显的垂直分层分布,土层越深酶活性越低;4个植被带土壤脲酶活性为1.28～3.87mg·g-1·24h-1,高山草甸>常绿阔叶林>亚高山矮林>针叶林;蔗糖酶活性为36.18～244.08mg·g-1·24h-1,高山草甸>针叶林>常绿阔叶林>亚高山矮林;磷酸酶活性和过氧化氢酶活性分别为0.18～0.62mg·g-1·2h-1和1.78～1.98ml·g-1·20min-1,高山草甸>针叶林>亚高山矮林>常绿阔叶林;土壤酶活性与土壤总有机碳、全氮显著正相关;与土壤温度、湿度、pH相关性比较复杂。

This paper measured the activities of soil urease, sucrase, acid phosphatase, and catalase in four typical vegetation zones, i. e. , evergreen broadleaf forest （EBF）, coniferous forest （CF）, sub-alpine dwarf forest （SDF）, and alpine meadow （AM）, along an altitude gradient in the Natural Reserve of the Wuyi Mountains in Fujian Province of East China. In the four zones, there were no significant seasonal variations in the activities of test enzymes except acid phospha- tase, whose activity was significantly higher in autumn than in any other seasons. The activities of test enzymes differed significantly with altitude, but less affected by the interaction of season and altitude. The enzyme activities showed an overall increasing trend with the altitude, being signifi- cantly higher in AM zone than in EBF and CF, and decreased with soil depth. The soil urease activity in the four zones was in the range of 1.28-3.87 mg·g^-1 ·24 h^-1, and in the order of AM〉EBF〉SDF〉CF; soil sucrase activities was in the range of 36.18-244.08 mg·g^-1.24 h^-1 , and in the order of AM〉CF〉EBF〉SDF; acid phosphatase and catalase activities were in the ranges of 0. 18-0. 62 mg· g^-1·2 h^-1 and 1.78-1.98 ml · g^-1·20 min^-1, respectively, and in the order of AM〉CF〉SDF〉EBF. The soil enzyme activities were significantly positively correlated with soil total organic carbon and total nitrogen, and had complicated correlations with soil temperature, moisture, and pH.