Fire size and vegetation productivity shape bird diversity across burned landscapes in the Atlantic Forest

Fires pose an increasing threat to tropical forests worldwide. However,
few studies have attempted to evaluate their impacts on bird communities.
Consequently, the responses of tropical birds to this disturbance remain
unclear. We assessed bird community composition, species richness, and
functional diversity between unburned and burned forests across 15
landscapes in the Brazilian Atlantic Forest. Additionally, we analyzed how
these indices were influenced by native forest cover, vegetation
productivity, fire severity, and fire size. To address these questions, we
applied generalized linear mixed models.  While unburned and
burned forests exhibited similar species richness and functional
diversity, they differed significantly in bird species composition.
Species richness was positively associated with vegetation productivity.
Functional diversity was primarily explained by fire size, with the
magnitude and direction of the effects varying according to the functional
index used and the forest type.  Functional divergence showed a
positive correlation with fire size in unburned forests and a negative
correlation in burned forests. Functional dispersion, when considering
communities across both forest types, was negatively correlated with fire
size. Synthesis and applications: This study highlights how bird
communities in the Atlantic Forest respond to fires. Our findings show
that fire can significantly alter species composition, even when species
richness remains unchanged. Bird community responses are further shaped by
vegetation productivity and fire size, emphasizing the need to consider
multiple ecological factors in post-fire conservation strategies. We
emphasize the need for tailored fire management strategies aimed at
reducing forest degradation and fire occurrence. Effective measures, such
as forest restoration and the implementation of 'fire-smart
management' practices, are essential to safeguard bird diversity.
These results underscore the need for proactive governmental policies to
prevent and manage fires in the Atlantic Forest, particularly in highly
degraded landscapes.