Altitudinal patterns of alpine soil ammonia-oxidizing community structure and potential nitrification rate

作者：Yuwei Zhao, Ning Ling, Xiang Liu, Chao Li, Xin Jing, Jingjing Hu, Junpeng Rui · 发表于：Applied and Environmental Microbiology · 年份：2024 · DOI：10.1128/aem.00070-24 · 被引用次数：7 · 研究领域：Microbial Community Ecology and Physiology、Wastewater Treatment and Nitrogen Removal、Soil Carbon and Nitrogen Dynamics

ABSTRACT Nitrogen availability limits the net primary productivity in alpine meadows on the Qinghai–Tibetan Plateau, which is regulated by ammonia-oxidizing microorganisms. However, little is known about the elevational patterns of soil ammonia oxidizers in alpine meadows. Here, we investigated the potential nitrification rate (PNR), abundance, and community diversity of soil ammonia-oxidizing microorganisms along the altitudinal gradient between 3,200 and 4,200 m in Qinghai–Tibetan alpine meadows. We found that both PNR and amoA gene abundance declined from 3,400 to 4,200 m but lowered at 3,200 m, possibly due to intense substrate competition and biological nitrification inhibition from grasses. The primary contributors to soil nitrification were ammonia-oxidizing archaea (AOA), and their proportionate share of soil nitrification increased with altitude in comparison to ammonia-oxidizing bacteria (AOB). The alpha diversity of AOA increased by higher temperature and plant richness at low elevations, while decreased by higher moisture and low legume biomass at middle elevations. In contrast, the alpha diversity of AOB increased along elevation. The elevational patterns of AOA and AOB communities were primarily driven by temperature, soil moisture, and vegetation. These findings suggest that elevation-induced climate changes, such as shifts in temperature and water conditions, could potentially alter the soil nitrification process in alpine meadows through changes in vegetation...