From Barren Rock to Thriving Life: How Nitrogen Fuels Microbial Carbon Fixation in Deglaciated Landscapes

作者：Yuhan Wang, Haijian Bing, Gentile Francesco Ficetola, Tao Wang, Chengjiao Duan, Tianyi Qiu, Wenzheng Yang, Yanrui Wu, Zhiqin Zhang, Yanhong Wu, Ji Liu, Wenfeng Tan, Linchuan Fang · 发表于：Environmental Science & Technology · 年份：2025 · DOI：10.1021/acs.est.5c00897 · 被引用次数：9 · 研究领域：Soil Carbon and Nitrogen Dynamics、Polar Research and Ecology、Microbial Community Ecology and Physiology

Rapidly expanding nascent ecosystems at glacier forefields under climate warming dramatically enhance the terrestrial carbon (C) sink. Microbial C fixation and degradation, closely implicated in nitrogen (N) transformation and plant–soil–microbe interactions, significantly regulate soil C accumulation. However, how shifts in microbial functional potential impact soil C sequestration during vegetation succession remains unclear. Here, we synchronized microbial C and N cycling genes in the rhizosphere and bulk soils across an ∼130-year chronosequence at the Hailuogou Glacier in the eastern Tibetan Plateau. Carbon fixation dominated microbial C cycling throughout the chronosequence, contributing to 74% of C-cycling gene abundances and increasing 3–6 times at the intermediate stage relative to the initial stage. Microbes favored energy-efficient and carbonate utilization pathways, such as the Wood–Ljungdahl and 3-hydroxypropionate cycles, to support high C-fixation potential. Ammonification, primarily driven by the ureC gene (>50% of N-cycling gene abundances), dictated N supply for plants and microbes. This enhanced soil N availability likely stimulated microbial biomass, diversity, and specific taxa, thereby optimizing C use efficiency. However, the ammonification-driven C fixation was contingent upon specific plant species at different succession stages. Our findings highlight the pivotal role of microbial N mineralization in shaping microbial communities and driving soil C ac...