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

Abstract:

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 of β-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.