Principal role of fungi in soil carbon stabilization during early pedogenesis in the high Arctic

• 成果类型: Article
• 署名作者: Trejos-Espeleta, Juan Carlos; Marin-Jaramillo, Juan P.; Schmidt, Steven K.; Sommers, Pacifica; Bradley, James A.; Orsi, William D.
• 署名单位: University of Munich; University of Colorado System; University of Colorado Boulder; Aix-Marseille Universite; Institut de Recherche pour le Developpement (IRD); Centre National de la Recherche Scientifique (CNRS); University of London; Queen Mary University London; University of Munich; Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9531
• DOI: 10.1073/pnas.2402689121
• 发表日期: 2024-07-09
• 关键词: successional glacier foreland; organic-matter; earliest stages; ny-alesund; bacterial; DYNAMICS; limitation; chronosequence; stoichiometry; amplification

摘要

Climate warming is causing widespread deglaciation and pioneer soil formation over glacial deposits. Melting glaciers expose rocky terrain and glacial till sediment that is relatively low in biomass, oligotrophic, and depleted in nutrients. Following initial colonization by microorganisms, glacial till sediments accumulate organic carbon and nutrients over time. However, the mechanisms driving soil nutrient stabilization during early pedogenesis after glacial retreat remain unclear. Here, we traced amino acid uptake by microorganisms in recently deglaciated highArctic soils and show that fungi play a critical role in the initial stabilization of the assimilated carbon. Pioneer basidiomycete yeasts were among the predominant taxa responsible for carbon assimilation, which were associated with overall high amino acid use efficiency and reduced respiration. In intermediate- and late- stage soils, lichenized ascomycete fungi were prevalent, but bacteria increasingly dominated amino acid assimilation, with substantially decreased fungal:bacterial amino acid assimilation ratios and increased respiration. Together, these findings demonstrate that fungi are important drivers of pedogenesis in highArctic ecosystems that are currently subject to widespread deglaciation from global warming.