Fire disturbances to manganese cycling in the plant-soil continuum

Fires are a common and probably the most pervasive disturbance to many terrestrial vegetated ecosystems. By burning a great portion of aboveground biomass and producing gases, aerosols, and solid residues deposited on the ground surface, as well as changing other ecosystem properties, fires not only immediately transform aboveground pools of ecologically important elements but, more importantly, has a lasting impact on their post-fire cycling. In this work, we focus on the immediate changes of fire to the chemistry of manganese (Mn) and evaluate the effects of vegetation-fire interactions. Leveraging field and laboratory studies, we characterized the chemical speciation and reactivity of Mn in ash samples and revealed the effects of vegetation and fire thermal conditions. Combined with ecosystem-dependent fire behaviors, the results were extrapolated to reveal the differential impacts of fires, in terms of immediate changes to and long-term effects on Mn cycling.