Marked Differences in Butterfly Assemblage Composition between Forest Types in Central Amazonia, Brazil

Amazonia comprises a mosaic of contrasting habitats, with wide environmental heterogeneity at local and regional scales. In central Amazonia, upland forest (terra firme) is the predominant forest type and seasonally flooded forests inundated by white- and black-water rivers (varzea and igapo, respectively) represent around 20% of the forested areas. In this work, we took advantage of a natural spatial arrangement of the main vegetation types in central Amazonia to investigate butterfly assemblage structure in terra firme, varzea and igapo forests at the local scale. We sampled in the low- and high-water seasons, combining active and passive sampling with traps placed in both the understory and canopy. Terra firme supported the highest number of butterfly species, whereas varzea forest provided the highest number of butterfly captures. The high species richness in terra firme may reflect that this forest type is floristically richer than varzea and igapo. Varzea is a very productive environment and may thus support a higher number of butterfly individuals than terra firme and igapo. Most butterfly species (80.2%) were unique to a single forest type and 17 can be considered forest type indicator species in this landscape. Floodplain forest environments are therefore an important complement to terra firme in terms of butterfly species richness and conservation in Amazonia.