Data for: Aridity and chronic anthropogenic disturbance as organizing forces of fruit-feeding butterfly assemblages in a Caatinga dry forest

Anthropogenic disturbances and climate change are expected to reorganize
biodiversity on multiple ecological levels from populations to ecosystems,
especially in arid and semiarid regions due to environmental filtering
imposed by water stress. This paper examines the individual and combined
effects of chronic anthropogenic disturbance and increased aridity on the
structure of fruit-feeding butterfly assemblages in a human-modified
landscape of Caatinga dry forest, in the northeast of Brazil. Butterflies
were recorded monthly across old-growth forest stands and their
assemblages were described in terms of taxonomic and functional
community-level attributes confronted with different levels of chronic
disturbance and aridity. Butterfly assemblages were species-poor but had
high species replacement (turnover) along both the chronic disturbance and
aridity gradients. We observed a negative effect of aridity on the alpha
and beta diversity of butterfly assemblages. Butterfly assemblages across
forest stands exposed to high levels of chronic disturbance and aridity
had a nested structure. Functional diversity (Rao’s Q) and the
community-weighted means (CWM) of ocellus-bearing species and
monocot-feeding larvae were negatively and positively affected by
increased aridity and chronic disturbance, respectively. Our findings
suggest that aridity and its combination with chronic disturbance have a
drastic effect on the structure of butterfly assemblages in the Caatinga
dry forest. These findings highlight that rainfall and chronic
disturbances as major drivers of biological reorganization in
human-modified landscapes. As aridity increases, Caatinga tends to support
taxonomically and functionally impoverished and highly distorted
assemblages.