Soil Chemical Characteristics in Areas Subject to Prescribed Burning Within Chapada dos Guimarães National Park, Mato Grosso, Brazil

Objective: Analyse and compare the chemical characteristics of the soil in different areas within the PNCG, subjected to prescribed burning in different years (1997, 2019, 2020 and 2021), in order to verify whether these can be considered recovered. Theoretical framework: Based on scientific articles found on search engines for scientific articles and in books in the areas of protected area management, fire management, fire and soil characteristics. This is to support the explanation of how soil characteristics, mainly chemical ones, can be modified by the action of fire. Method: Areas with prescribed burns carried out in 1997, 2019, 2020 and 2021 were delimited. Prior to collecting soil samples, a mapping of the sampling points within each area (plot) was carried out. Subsequently, the deformed samples were collected at depths of 0 - 5 cm, 5 - 10 cm and 10 - 20 cm, at three different points in each plot. The data were subjected to statistical analysis to compare the means from the Tukey test at 5% using Sisvar and the graphs were produced with the aid of the PAST program. Results and conclusion: Prescribed burning influenced the base contents regardless of the depth analyzed and the period. The fire increased the availability of elements such as Ca, Mg, P, K, Cu, Fe, Mn and B, however, the increase in the contents of these elements, in general, did not remain for more than one year. Thus, it affected the content of OM, SB, CTC and V% of the soil. Implications of the research: These results indicate that significant fire activity occurs primarily in periods close to the time of its occurrence. Therefore, prescribed burning is a practice in which fire rapidly affects the chemical characteristics of the soil. As soon as the environment begins to produce more organic material, these tend to return to their natural conditions. Therefore, prescribed burning may be recommended for conservation areas in order to reduce potential forest fires. Originality/value: Controlled use of fire to reduce combustible material in conservation areas, to avoid fire events during dry periods.