Fostering biodiversity in Neotropical savannahs: fire as a diversity driver for fruit-feeding butterfly assemblages in the Brazilian Cerrado

Abstract Fire has significantly shaped the dynamics of Brazilian Cerrado fauna and flora, but the interference of human activities and climate change has disrupted the natural fire regime, imperiling multiple animal and plant populations. Our study, performed at Reserva Ecológica do Roncador (RECOR) in Brasília-Brazil, examined the influence of fire frequency and post-fire intervals on diversity patterns of fruit-feeding butterflies in savannah woodlands. We sampled 1012 individuals from 16 butterfly species, in which Biblidinae and Charaxinae were the most representative clades. Sites with higher fire frequency and shorter post-fire intervals exhibited greater taxonomic, functional and phylogenetic diversity compared to sites with longer intervals. Sites with longer post-fire intervals were primarily dominated by Biblidinae, whereas charaxines and satyrines mostly occurred in sites with shorter post-fire intervals. Species with wing eyespots and temporal restrictions thrived in sites with recent fires. These findings emphasize fire's pivotal role in maintaining open vegetation, crucial for conserving butterfly assemblages, particularly charaxines and satyrines. Importantly, fire suppression leads to fuel accumulation, elevating the risk of severe wildfires in the Cerrado. In conclusion, our results underscore the adverse impact of a zero-fire policy on insect communities, including fruit-feeding butterflies, within this unique ecosystem.