POST-FIRE NATURAL REGENERATION OF HIGH ALTITUDE GRASSLANDS IN THE ITATIAIA NATIONAL PARK, SOUTHEAST OF BRAZIL

Abstract

The anthropogenic fire is a major threat to the high altitude grasslands of the Itatiaia National Park - INP, where over 70% of cases of fire in this ecosystem in the state of Rio de Janeiro. However, their impacts are still unknown. Understand the processes associated with the regeneration of high altitude grasslands after fire is suggested by the Management Plan of INP. The objective of this study was to evaluate the floristic composition and structure of the plant community in four sites located at 2500 m altitude and with different historical fires (1988, 2001, 2007 and 2010). It was studied area of 1600 m² divided between grassland and vegetation islands on rocky outcrops. In total were sampled 167 species of angiosperms and 16 ferns and lycophytes, with 32% endemic species and 11% threatened. Asteraceae showed nearly 20% of the species among the 63 registered families. There was flo­ristic similarity within and between sites comparing the two vegetation types, with rocky outcrops showing lower values. Life forms, habit and dominance (coverage area) were also similar between sites. The number of species from four to seven years after fire had a significant increase (30% of species), with sites in 1988, 2001 and 2007 with values above 80% of the recorded species. Despite of the re-establishment, structure, composition and richness of vegetation have occurred relatively quickly (between 4 and 7 years), endemic and endangered species were not found after fire. Whereas some of these threatened species can be in the disappearance process, the execution of population studies, reproductive and ecophysiological becomes a priority, as well as studies on the fire ecology in this environment.