Post-fire recovery of a dense ombrophylous forest in amazon

Abstract

The fires that occur in the Amazon are as damaging as the deforestation is. There is a need for further long-term studies on dynamics of tree communities in forests affected by fires. In the present study we evaluated the dynamics of tree species, before and after an accidental fire that occurred in 1997 in an experimental area of terra firme forest in the Floresta Nacional do Tapajós, in western Pará State, Brazil. Approximately 3500 trees with diameter measured at 1.30 m above ground (DBH) ≥ 5 cm were botanically identified and measured in 12 permanent plots of 0.25 ha (50 m x 50 m), in 1983, 1987, 1989, 1995, 2008 and 2012. Analyses of survival, mortality and recruitment of trees were performed. The results showed that although the fire has increased the mortality and recruitment rates after 15 years, the highest mortality occurred on trees with smaller diameters (DBH < 30 cm), so the fire did not affect the survival of large trees in the long term, explaining why the reduction in density of living trees has not greatly influenced the decrease in basal area in the burned forest.