Resistance to fire and the resilience of the woody vegetation of the Cerradao'' in the Cerrado''-Amazon transition zone

The savanna formations of the Brazilian ''Cerrado'' present a high degree of resistance and resilience to the impacts of fire, although little is known of its forest formations. Given this, the present study evaluated the resistance and resilience of the ''Cerradao'' to fire impacts over a 7-year period. In March 2008, we established 50 permanent plots of 10 m X 10 m and measured all the woody individuals with a base diameter >= 5 cm. Six months later, all plots were burned by an accidental fire. In March 2012 and March 2015, we re-measured all surviving individuals, and measured the recruits. Species richness, the density of individuals, and the basal area were all significantly greater ( P < 0.05) in 2008, prior to the fire, in comparison with 2012 and 2015, after the fire. Species richness and the density of individuals were also higher ( P < 0.05) in 2015, about 7 years post-fire, in comparison with 2012. During the interval in which the fire occurred ( 2008-2012), the mortality and reposition time, and the stability were all higher ( P < 0.05) than during the subsequent interval, post-fire ( 2012-2015). The recruitment rate was also lower between 2008 and 2012 ( P < 0.05). Our results indicate that the ''Cerradao'' has reduced resistance and resilience to the disturbances caused by fire relative to savanna formations. Given this, frequent burn-off may cause drastic alterations to this phytophysiognomy, emphasizing the need for special care for the preservation of its biodiversity.