Effects of Wildfires on Mycorrhizal Activity in Cerrado Soils

Wildfires are recurrent phenomena in the Cerrado and can significantly impact soil microbiota, including arbuscular mycorrhizal fungi (AMF). These microorganisms play a key role in nutrient cycling, soil aggregation, and ecological resilience, making them crucial for ecosystem recovery after disturbances.
This study evaluated the effects of a mega-fire on the AMF community and its parameters in soils under Cerrado vegetation. The research was conducted in the Chapada dos Veadeiros National Park, Goiás, Brazil, where the largest recorded fire in the region occurred on October 10, 2017, affecting an area of 66,000 hectares. AMF spore density, root mycorrhizal colonization rate, easily extractable glomalin (EEG), and the presence of AMF genera were analyzed in burned and unburned areas of five common Cerrado phytophysiognomies.
The results indicated that fire immediately affected the mycorrhizal community parameters in Cerrado soils, with a tendency to recover over time. The presence of AMF genera did not differ between burned and unburned areas, with Acaulospora, Claroideoglomus, Diversispora, Glomus, Funneliformis, Sclerocystis, and Gigaspora identified in both conditions. The recovery of the AMF community after fire events was also observed in the evaluated mycorrhizal parameters, as spore density, root colonization rates, and EEG values were similar between burned and unburned areas.
These findings highlight the resilience of AMF and their crucial role in Cerrado soil recovery following fire events, reinforcing their importance in maintaining ecosystem structure and function.