Soil organic matter properties drive microbial enzyme activities and greenhouse gas fluxes along an elevational gradient

作者：Xingguo Han, Anna Doménech‐Pascual, Joan Pere Casas‐Ruiz, Jonathan Donhauser, Karen Jordaan, Jean‐Baptiste Ramond, Anders Priemé, Anna M. Romaní, Aline Frossard · 发表于：Geoderma · 年份：2024 · DOI：10.1016/j.geoderma.2024.116993 · 被引用次数：21 · 研究领域：Soil Carbon and Nitrogen Dynamics、Atmospheric and Environmental Gas Dynamics、Peatlands and Wetlands Ecology

Mountain ecosystems, contributing substantially to the global carbon (C) and nitrogen (N) biogeochemical cycles, are heavily impacted by global changes. Although soil respiration and microbial activities have been extensively studied at different elevation, little is known on the relationships between environmental drivers, microbial functions, and greenhouse gas fluxes (GHGs; carbon dioxide [CO2], methane [CH4] and nitrous oxide [N2O]) in soils of different elevation. Here, we measured how in situ GHG fluxes were linked to soil properties, soil organic matter (SOM) quantity and composition (the proportion of humic-like vs. protein-like OM), microbial biomass, enzyme activities and functional gene abundances in natural soils spanning an elevational gradient of ∼2400 m in Switzerland. Soil CO2 fluxes did not significantly vary from low (lowland zone) to higher (montane and subalpine zones) elevation forests, but decreased significantly (P<0.001) from the treeline to the mountain summit. Multivariate analyses revealed that CO2 fluxes were controlled by C-acquiring enzymatic activities which were mainly controlled by air mean annual temperature (MAT) and SOM quantity and composition. CH4 fluxes were characterized by uptake of atmospheric CH4, but no trend was observed along the elevation. N2O fluxes were also dominated by uptake of atmospheric N2O. The flux rates remained stable with increasing elevation below the treeline, but decreased significantly (P<0.001) from the treeline...