The Cerrado is the second largest Brazilian biome and one of the main biodiversity hotspots on the planet, and has recently gained prominence as the last agricultural frontier with food production potential in the Americas. The Cerrado soils are old, deep, not very fertile, acidic and very weathered, however they have a great wealth of biodiversity of fungi and bacteria, which play fundamental roles for the resilience and maintenance of life in this biome. This biodiversity is adapted to the seasonal edaphoclimatic conditions of the cerrado, divided into dry and rainy seasons, which also confer great resilience and high recovery power to situations of environmental stress, such as forest fires for example. Understanding how fungal and bacterial communities in cerrado soils work is essential to understand the role of these organisms and their behavior in stressful situations such as lack of water and forest fires. In view of the above, this work aims to verify the influence of forest fires and seasonal variations on the dynamics of total microorganisms in the soil of five Cerrado phytophysiognomies. The samples were taken from Chapada dos Veadeiros National Park, a permanent preservation area with areas of Cerrado Nativo without human influence. The five main phytophysiognomies of the Cerrado biome were chosen: clean fields, dirty fields, cerrado sensu stricto, cerradão and Veredas. Total organisms and fungal and bacterial colony forming units were counted. The Cerradão phytophysiognomy presented the highest values of fungal and bacterial colony forming units when compared to the other phytophysiognomies. The floristic biodiversity of the cerradão reflects a greater associated edaphic microbial biodiversity.

Keywords: Cerrado, Soil microorganisms, seasonal change