Effects of different fire regimes on dynamics of plant communities in a Tropical Savanna

Abstract

Fire is an ecological factor present in several ecosystems around the world, which acts to shape plant communities. The passage of fire affects individuals, even communities, changing the environmental conditions and the interspecific relationships of plants, consequently the dynamics of the plant community. The fire regime can be considered as one of the determining factors in the structuring and maintenance of the Cerrado. In this way, the main objective of this study is to analyze how different burning regimes influence in the medium term the structure, composition, dynamics and species and functional diversity of the plant communities of Cerrado open physiognomies, as well as the post-burning environmental conditions. It is also intended to determine which factors influence the fire behavior in the Cerrado, through analysis of areas with different times and frequencies of fire and environmental characteristics. For this, vegetation surveys and biomass collection will be carried out in areas with different fire frequencies (> 9 years without burning, burned annually and biennially for 7 years), fire season (burned at the beginning, middle and end of the dry season) which will provide community composition, structure and productivity data. The surveys, including coverage (%) and reproductive branch count, will be carried out in 1x1m subplots (10 subplots/treatment, 4 plots/treatment). We will also sample for all treatments, in the rainy season of 2023, functional attributes related to the response of plants to the fire regime (10 individuals/treatment). Through data loggers with sensors of relative humidity, light, and temperature installed in the plots under treatments with different firing frequencies and physical and chemical analysis of soil samples in these same plots, we will evaluate how the environmental conditions are influenced by the frequency of fire. Finally, it seeks to evaluate through the propagation rate (ms-1), burning efficiency (%), and fire intensity (kW.m-1) among other fire parameters, the effects of the burning regimes, and the environmental characteristics of each area in the behavior of the fire. What should contribute to the development of fire management strategies for the conservation of this ecosystem. (AU)