Forever young: arrested succession in communities subjected to recurrent fires in a lowland tropical forest

Fire in tropical forests jeopardizes natural regeneration and can lead to the establishment of an alternative stable state. To address the effects of fire on natural regeneration in a lowland tropical forest, we performed a time series study over 12 years, focusing on the impact of fire frequency and post-fire regeneration time on vegetation structure, diversity, and functional composition in secondary forests. The study was conducted in the Brazilian Atlantic Forest at sites subjected to different fire frequencies (never, once, three, and four times over 44 years) and old-growth forests. During 12 years of monitoring time, no significant difference was observed in community structure and diversity among sites subjected to fire, which suggests an arrested succession pattern and corroborates with the establishment of an alternative stable state. Functional traits associated with fire resistance, including wood density and bark thickness, were higher in areas with fire history compared to old-growth forests. Therefore, our results showed that recurrent fires can lead communities toward an arrested succession pattern with a high divergence in community structure and functional composition compared to old-growth forest. These results have several practical implications for restoration and conservation programs in the Brazilian Atlantic Forest.

Automated summary

Fire in tropical forests can hinder natural regeneration and lead to the establishment of an alternative stable state. This study investigated the impact of fire frequency and post-fire regeneration time on vegetation structure, diversity, and functional composition in secondary forests over a 12-year period. The results showed that there was no significant difference in community structure and diversity between sites subjected to fire and those that were not, indicating an arrested succession pattern and the establishment of an alternative stable state.