川西高寒地区不同海拔高度土壤酶活性特征研究

Study on soil enzyme activity characteristics at different altitudes in the alpine region of Western Sichuan

为增进对川西高寒地区土壤微生物的能量和养分限制状况的了解,以川西地区不同海拔高度(2969 m,3280 m,3697 m和3992 m)的土壤为研究对象,通过测定土壤的酶活性和相关理化性质,探讨了川西地区土壤酶活性和酶化学计量沿海拔的分布规律及其影响因素.结果表明:(1)土壤的β-1,4-葡萄糖苷酶(BG)、纤维二糖水解酶(CBH)、β-1,4-N-乙酰氨基葡萄糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)和酸性磷酸酶(AP)活性随着海拔的增加,呈现出先减小后增大的分布模式.具体表现为土壤BG、CBH和AP酶活性在海拔3992 m处最大,在海拔3280 m处最小.土壤NAG和LAP酶活性在海拔2969 m处最大,在海拔3697 m处最小.(2)海拔3280 m的土壤微生物相对受氮、磷限制,而其余三个海拔的土壤微生物相对受碳、磷限制.(3)铵态氮、全氮、全碳和土壤养分的化学计量是驱动土壤酶活性及酶化学计量沿海拔变化的关键因素.从结果可知本研究区域的土壤酶活性特征与环境资源的可用性相关.

In order to improve the understanding of the energy and nutrient limitation of soil microorganisms in the alpine region of western Sichuan,the soils at different altitudes(2969 m,3280 m,3697 m and 3992 m)in the alpine region of western Sichuan were used as the research object.By measuring soil physicochemical properties and extracellular enzyme activities,the distribution law of soil enzyme activity and enzyme stoichiometry along the altitude and its influencing factors were discussed.The results showed that:(1)The activities ofβ-1,4-glucosidase(BG),Cellobiohydrolase(CBH),β-1,4-N-acetylglucosaminidase(NAG),Leucine aminopeptidase(LAP)and Acid phosphatases(AP)showed a distribution pattern of first decreasing and then increasing with the increase of altitude.Specifically,the activities of carbon and phosphorus acquisition enzymes were the highest at 3992 m,and the lowest at 3280 m.The highest nitrogenacquisition enzyme activity was at 2969 m,and the lowest was at 3697 m.(2)Soil microorganisms at 3280 m were relatively limited by N and P,while those at the other three altitudes were relatively limited by C and P.(3)Soil ammonium nitrogen(NH+4-N),total nitrogen(TN),soil total carbon(TC),and soil nutrient stoichiometry were the key factors driving the changes in soil enzyme activities and their stoichiometry along the altitude.According to the results,the characteristics of soil enzyme activities in this study area were related to the availability of environmental resources.