Habitat heterogeneity shapes multiple diversity dimensions of fruit-feeding butterflies in an environmental gradient in the Brazilian Cerrado

Habitat heterogeneity affects species distribution, and a better understanding of this relationship can inform biodiversity conservation. To understand how habitat heterogeneity affects multiple dimensions of biodiversity, we sampled fruit-feeding butterflies within savannah woodlands and gallery forests from July 2012 to June 2013 in the Cerrado. A total of 3459 individuals representing 56 species were collected, with 32 found in savannah and 51 in gallery forest. In addition to taxonomic diversity, gallery forests host higher functional (Gower = 0.72) and phylogenetic diversity (Faith's PD = 641.5) compared to savannahs (Gower = 0.61; Faith = 416.1, respectively). Within gallery forests, butterfly assemblages exhibited higher functional diversity in the understory (Gower = 0.8) than in the canopy (Gower = 0.6). Similarly, phylogenetic diversity was higher in understory (PD = 573.9) compared to canopy (PD = 391.9) within the savannah. Species with smaller bodies (CWMsize = 27.8), broader diet breadth (CWMdiet = 2642), and defense-related traits (CWMeyespots = 65% of the assemblage), tended to be found in gallery forests compared to savannah woodland (CWMsize = 29.4; CWMdiet = 1527; CWMeyespots = 35% of the assemblage), respectively. Gallery forests are marked by more stable and less severe microclimate, reinforcing their pivotal role as a climatic refuge for most species, with a particular emphasis on smaller, desiccationprone species. Furthermore, habitat heterogeneity may provide new ecological niches, which contribute to the high butterfly diversity in the Cerrado biome. Gallery forests offer favorable conditions for a higher proportion of butterfly assemblages, whereas savannah woodlands host distinct functional groups, including larger-bodied, camouflaged, and dietary specialist species. In light of this, we strongly advocate for the preservation of the gallery forest-savannah ecotone, in order to promote the coexistence of diverse butterfly lineages and functional groups.