Abstract:Studying the dynamic changes of soil enzyme activities and its stoichiometric characteristics at the micro-scale altitude and aspect of alpine meadows has important ecological significance for exploring the nutrient cycling process of grassland ecosystems. The alpine meadows in eastern Qilian Mountain was taken as the research object, and the changes of soil enzyme activities and its stoichiometric characteristics in seven altitudes and two aspects of alpine meadows, and their relationships with soil physical and chemical factors were analyzed. The results showed that the interactive effects of altitude and aspect had significant effects on soil LAP, BG, PPO, POD, lnBG/ln(NAG+LAP), lnBG/lnAP and ln(NAG+LAP)/lnAP. The LAP, AP, BG, POD, lnBG/ln(NAG+LAP) and lnBG/ln(NAG+LAP) first increased and then decreased with the increasing altitudes, while NAG and PPO decreased with the increasing altitudes. At the same altitude, The AP, BG, POD and PPO in the sunny aspect were lower than those in the shady aspect, and NAG in the sunny aspect were higher than that in the shady aspect, and LAP in sunny aspect under 3 800 m were lower than that in the shady aspect, and lnBG/ln(NAG+LAP) in sunny aspect except 3 000 and 4 000 m were higher than that in the shady aspect, and lnBG/lnAP in sunny aspect under 3 000 to 4 000 m and ln(NAG+LAP)/lnAP in sunny aspect under 3 000 to 3 600 m were lower than that in the shady aspect. Correlation analysis found that, soil enzyme activity and its stoichiometric characteristics were regulated by soil C, N, P resources and soil moisture conditions to varying degrees, and soil moisture and SOC were the main factors affecting soil enzymes activities. In conclusion, soil enzymes activities and their stoichiometric characteristics were different in micro-scale elevations and slope directions, and were affected by soil C, N, P resources and soil moisture conditions, especially soil water content and SOC.