Data from: Butterfly community ecology: the influences of habitat type, weather patterns, and dominant species in a temperate ecosystem

We compared variation in butterfly communities across 3 years at six
different habitats in a temperate ecosystem near Boulder, Colorado, USA.
These habitats were classified by the local Open Space consortium as:
Grasslands, Tallgrass, Foothills Grasslands, Foothills Riparian, Plains
Riparian, and Montane Woodland. Rainfall and temperature varied
considerably during these years. We surveyed butterflies using the
Pollard-Yates method of invertebrate sampling, and compared abundance,
species richness, and diversity across habitats and years. Communities
were most influenced by habitat, with all three quantitative measures
varying significantly across habitats but only two measures showing
variation across years. Among habitats, butterfly abundance was higher in
Plains Riparian sites than in Montane Woodland or Grassland sites, though
diversity was lowest in Plains Riparian areas. Butterfly species richness
was higher in Foothills Riparian sites than it was in all but one other
habitat (Tallgrass). Among years, butterfly abundance and species richness
were lower during the year of least rainfall and highest temperatures,
suggesting a substantial impact of the hot, dry conditions. Across
habitats and years, butterfly abundance was consistently high at Plains
Riparian and Foothills Riparian sites, and richness and diversity were
consistently high in Foothills Riparian areas These two habitats may be
highly suitable for butterflies in this ecosystem, regardless of weather
conditions. Generally low abundance and species richness in Montane
Woodlands sites, particularly in 2002, suggested low suitability of the
habitat to butterflies in this ecosystem, and this may be especially
important during drought-like conditions. Finally, to examine the effect
that the presence of the very abundant non-native species Pieris rapae L.
(Lepidoptera: Pieridae) has on these communities, we re-analysed the data
in the absence of this species. Excluding P. rapae dramatically reduced
variation of both butterfly abundance and diversity across habitats,
highlighting the importance of considering community membership in
analyses like ours.