Impacto do incêndio florestal na comunidade arbórea de uma Floresta Ombrófila Mista Aluvial Altomontana na Serra da Mantiqueira Meridional (Minas Gerais)

Abstract

Forest fire can severely impact the vegetation depending on its intensity, duration, frequency and the type of vegetation affected. Knowing that forest fires is one of the main causes of the decline of Mixed Rain Forest (MRF) and also the quantitative study in this vegetation type is rare, therefore, is important to study the impact of forest fire in this type of vegetation. The following hypothesis was raised: forest fires is able to change the structure, composition, diversity and ecological groups of tree community. The study was conducted in the Parque Estadual da Serra do Papagaio (PESP), which includes the single remnant of MRF in a Conservation Unit of integral protection in Minas Gerais State. Two areas were chosen to comparison, one that has no history of forest fires in the last 30 years (Area I) and another that has anthropogenic forest fire recently (2011) (Area II). Were allocated 25 permanent plots of 20 x 10 m in each area and every shrub and tree vegetation with DBH ≥ 4.8 cm was measured, identified and height estimated. The initial hypothesis was refuted partially, because there was difference only in diversity and community structure (density and basal area). The Area II presented less live individuals (reduction of 30%) and less basal area (reduction of 35%) than community of Area I. The number of dead individuals differed significantly between the two areas, where most dead individuals were concentrated in the smaller diameter classes (DBH < 9.8 cm). This study was important to show that forest fire has relevant role in modifying the structure and diversity of vegetation, therefore, preventive efforts against fire in MRF are important to preserve this threatened physiognomy.