Ectomycorrhizal mediation of soil carbon sequestration: from carbon allocation to necromass stabilization and priming effects

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:This review provides a comprehensive overview of current knowledge and identifies key gaps for future research on ECM-mediated soil carbon dynamics.

🏢実務担当者:Land managers and forestry practitioners can gain insights into how ECM fungi influence soil carbon storage, informing sustainable forest management practices.

🏛政策担当者:Policymakers can use this to understand uncertainties in forest carbon sinks, guiding decisions on climate mitigation strategies and carbon accounting standards.

Ectomycorrhizal (ECM) fungi form the dominant symbiosis in many of the world's forest biomes. They exert a seemingly contradictory influence on soil carbon (C), simultaneously promoting C accrual through necromass inputs and aggregate protection, while also driving C loss via enzymatic priming. This review synthesizes current understanding of these dual roles, focusing on: (1) the magnitude and controls of photosynthetic C allocation from host plants to ECM mycelium; (2) the enzymatic mechanisms of SOM decomposition, the rhizosphere priming effect, and the contested universality of the “Gadgil effect” (competitive suppression of free-living saprotrophs); (3) physical and chemical stabilization pathways including the “microbial carbon pump” (necromass accrual) and “mineral carbon pump” (organo-mineral complexation); (4) environmental controls including nitrogen deposition, climate change, and forest management practices; and (5) prevailing research controversies and key methodological constraints—including isotope dilution, spatial heterogeneity of hyphal networks, and uncertain biomarker conversion factors—in quantifying fungal-mediated C fluxes. We identify key knowledge gaps, notably the need for explicit integration of ECM functional traits into ecosystem C models, resolution of the net balance between priming and stabilization under varying edaphic conditions, and a mechanistic understanding of how global change drivers alter ECM-C relationships. Future research should prioritize multi-scale approaches that integrate molecular omics, high-resolution isotope tracing, and process-based modeling to better constrain the role of ECM fungi in forest soil C sequestration and vulnerability. We further highlight that the ecological significance of ECM fungi in the global carbon cycle extends well beyond the well-studied northern forests, encompassing extensive tropical and Southern Hemisphere ECM systems that are subject to fundamentally different nutrient economies and global change pressures.

• openalex https://doi.org/10.3389/fmicb.2026.1865735first seen 2026-06-26 05:11:12