Forest islands sustain more temporally stable insect metacommunities in a heterogeneous tropical mountaintop landscape

We evaluated how habitat type influences community temporal dynamics in a heterogeneous tropical mountain landscape. We sampled ants, dung beetles, and fruit-feeding butterflies across two mountaintop habitats: campo rupestre and forest islands in the Southern Espinhaço Range, Brazil. We quantified temporal dynamics by assessing variations in species richness across sampling years and in species composition, focusing on species gains and losses. Species richness did not differ between environments and most species were unique to either campo rupestre or forest islands. We found no consistent pattern of species gains or losses among insect communities or habitat types, with such temporal dynamics being more prevalent for butterflies in the campo rupestre. In the campo rupestre, recent periods were dominated by colonization-driven homogenization following widespread species losses. In forest islands, extirpations prevailed for ants, colonizations for butterflies, and processes were balanced for dung beetles. The campo rupestre showed greater temporal dynamics in species richness and composition, particularly for butterflies and dung beetles, resulting in more frequent species gains. Habitat type shapes the temporal dynamics of insect communities in heterogeneous tropical mountaintop landscapes. Forest islands sustain more temporally stable insect metacommunities, while open environments and more mobile organisms have greater temporal dynamics.