Fire-induced geochemical changes in soil: Implication for the element cycling

Soils play an essential role in supporting and sustaining life on this planet. In fire-impacted environments, fire causes considerable changes to the soil, especially in the various elements. The present work provides a comprehensive and up-to-date review of the effect of fire on soil geochemistry, and its impact on the cycling of different biogenic, major, minor, and trace elements in the soil. Results from both natural and experimental fires (field-scale and lab-scale) are considered in this review. The temperature at which mineral transformation occurs in the soil during fires is summarised. The review suggests that fires can significantly alter mobility and hence, the cycling of many elements in fire-affected regions. Change in speciation of elements following fires risks formation and/or increased availability of the toxic forms of elements in the soil. The unique physical, chemical, and biological conditions observed during fires make many unlikely reactions more likely. However, the information available in the literature is often fire, vegetation, and element specific. More studies on this topic by changing these three variables will improve our understanding of changes in the soil caused by fire. Hence, with fires being touted to increase global presence in the coming years, more studies on understanding their effects on soils are recommended.

Automated summary

Soils have a vital role in supporting and sustaining life on Earth. Fires cause significant changes in soil, particularly in relation to various elements. This review provides a comprehensive and up-to-date examination of the impact of fire on soil geochemistry and the cycling of different biogenic, major, minor, and trace elements. The findings suggest that fires can greatly affect the mobility and cycling of elements in fire-affected areas. Changes in element speciation following fires may lead to the formation and/or increased availability of toxic forms in the soil. More research is needed to explore the effects of fire on soil, taking into account variations in fire, vegetation, and elements.