Influence of fire regime on the taxonomic and phylogenetic diversity of frog communities in a fire-prone Brazilian ecosystem

Abstract

Fire is a natural disturbance that has shaped Earth's biodiversity for millions of years. In a fire-prone ecosystems, fire acts as an important environmental filter, selecting species presenting tolerant traits to fire events and post-fire environmental conditions. It is expected that intense fire activity selects for closely-related species, thus promoting a phylogenetic and functional clustering of communities. In view of the severe changes in natural fire regimes observed in different regions of the planet, an increasing body of research has been dedicated to exploring their impact on frogs, a particularly susceptible group in the context of wildfires. However, it is notable that most of the research focuses on the traditional dimension of diversity, the taxonomic diversity, leaving a significant gap in our understanding of how fire disturbances affect the phylogenetic diversity of these communities. Here, we tested the effects of three fire regime parameters (i.e., total burned area, time since the last fire and fire count at the landscape scale) on the taxonomic and phylogenetic diversity of frog communities in 26 sites within a fire-prone Brazilian protected area. We used Hill numbers to characterize the taxonomic (Species richness, Shannon and Simpson's diversity) and phylogenetic diversity (Phylogenetic richness, Mean phylogenetic diversity of common lineages and Mean phylogenetic diversity of dominant lineages). We found that the fire regime did not explain patterns of the taxonomic diversity. Nonetheless, there was a positive correlation between phylogenetic richness and the frequency of fire occurrences, while a slight negative correlation was observed with the percentage of burned area. In addition, moderate fire activity seems to be an important driver of phylogenetic diversity. Therefore, management practices toward a mosaic of areas with different fire histories are fundamental in this protected area. We finally emphasize that all diversity facets of anurans should be assessed and considered in management decisions to guaranteeing anuran conservation in this region.