宁夏农林科学院开放基金项目(KF202203)；国家自然科学基金项目(32201631)；宁夏重点研发计划项目(2022BSB03069，2021BEG02005)资助。*通讯作者 Corresponding author．E-mail: email@example.com
Soil extracellular enzymes are closely related to the metabolic requirements and nutrient supply of microorganisms and are major players in biogeochemical cycles. However, the status of soil microbial nutrient limitation and its drivers in mountain ecosystems along the elevation gradient are not well understood in the arid regions. Taking the soils of seven elevation gradients from 1300 m to 2700 m in Helan Mountain as the research object, this paper revealed the elevation distribution patterns of soil physical and chemical properties, extracellular enzyme activities and microbial nutrient limitation, and analyzed the driving factors affecting microbial nutrient limitation. The results showed that with the increase of altitude gradient, the soil water content (SWC) and soil organic carbon (SOC) gradually increased, the bulk density (BD) and pH gradually decreased. Altitude had significant effect on soil extracellular enzyme activities, and the activities of five enzymes involved in soil carbon (C), nitrogen (N) and phosphorus (P) cycles gradually increased with the increase of altitude. Vector analysis of extracellular enzymes showed that the vector length was higher at mid and low altitudes, while the vector angle was higher at high altitudes, indicating that soil microorganisms in Helan Mountain had relatively strong C limitation at mid and low altitudes, and P limitation at high altitude. Soil moisture content, bulk density, C, N and P contents were significantly correlated with soil extracellular enzyme activities and their stoichiometric ratios, which were main factors regulating soil extracellular enzyme activities with altitude, indicating that the extracellular enzymes played an important role in soil material cycling in arid mountainous ecosystem. The study results provide a scientific basis for revealing the coupling mechanism of nutrient element cycling between soil microorganisms and extracellular enzymes, and for further exploring the material cycling of the forest ecosystem and the effective management of vegetation at different altitude gradients in Helan Mountain.
庞丹波,吴梦瑶,吴旭东,倪细炉,董立国,陈 林,李学斌,胡 杨.贺兰山东坡不同海拔梯度土壤酶化学计量特征研究.生态学报,,(). http://dx. doi. org/10.5846/stxb202210192978复制