Moth Communities Correspond with Plant Communities in Midwestern (Indiana, USA) Sand Prairies and Oak Barrens and Their Degradation Endpoints

Abstract

Despite immense diversity, insect conservation is typically species specific. Effective insect conservation will require efforts that capture insect species and communities at all levels of biological organization. Surrogate conservation targets, such as habitat based conservation planning tools were designed to capture poorly understood taxa such as invertebrates. We evaluated a botanically-based community filter across disturbance gradients in NW Indiana to determine if moth communities (Lepidoptera) responded similarly to vascular plant assemblages. Our 13 sample sites included high-quality ecosystem remnants (sand prairies and oak barrens) and their local degradation endpoints (exotic old fields and fire-suppressed oak woodlands). Monthly, we quantitatively sampled moths using ultraviolet light traps and inventoried vascular plant species at each sample site. Analysis of moth and plant community relationships using Bray-Curtis coefficients of dissimilarity produced statistically congruent relationships between moth and plant assemblages at the sample sites indicating that these two taxonomic groups respond to ecological gradients and disturbance similarly. Other measures of botanical community integrity used to select conservation areas such as floristic quality assessment index and diversity indices do not translate directly to measures of moth species richness or diversity. We suggest that in this system, vascular plant assemblages are a reasonable conservation surrogate for moth communities.