Impact of Fire and Heat Stress on Soil Microorganisms: A Review of Community Changes, Molecular Responses and Plant-Beneficial Roles.

Fire, whether occurring on the surface or underground, significantly influences soil microbial dynamics by reshaping community composition, functional diversity and overall soil and plant health. This review examines the effects of fire on soil-beneficial microbial communities, with particular attention to how surface and underground fires drive shifts in microbial diversity and functional roles within the agroecosystems. These changes impact key processes such as nutrient cycling, soil physicochemical structure and organic matter decomposition, ultimately affecting crop production. Bacterial groups such as Firmicutes and Actinobacteria often increase in abundance following fire events, while others lacking survival strategies tend to decline. Resilient fungal groups, including Ascomycota (such as Aspergillus, Penicillium and Trichoderma), frequently play pivotal roles during the recovery process. Fire can also enhance microbial metabolic activity, particularly in pathways involved in organic matter degradation, leading to short-term increases in nutrient availability that support plant regrowth. Finally, the review discusses the molecular responses of microbes to fire and outlines perspectives for better understanding this type of stress and how it affects the beneficial soil microbiota in agricultural edaphic systems.