Arbuscular mycorrhizal fungi as a hub for soil carbon transformation in intercropping systems: a review of microbial mechanisms and ecological significance

Abstract

Arbuscular mycorrhizal fungi (AMF) play a pivotal role in soil organic carbon (SOC) dynamics by channeling plant-assimilated carbon into both labile and recalcitrant pools. In intercropping systems, AMF form symbiotic associations with host plants and facilitate nutrient exchange across the plant-fungus-soil continuum, which consequently enhances soil nutrient availability. Through transforming photosynthetic carbon into diverse organic fractions, AMF exert a dual influence on SOC reserves by promoting both carbon stabilization and decomposition. This review synthesizes current evidence for a conceptual framework centered on AMF life-history strategies, proposing that trade-offs between plant growth promotion and SOC storage are context dependent and modulated by fungal functional traits and community composition. Elucidating AMF mediated carbon transformation in intercropping systems is therefore critical for understanding carbon turnover mechanisms under diversified cropping regimes. Such knowledge not only supports yield improvement, soil structural reinforcement, and ecological restoration but also provides a theoretical foundation for developing sustainable soil management and rehabilitation strategies.