The Effects of Flooding on Floodplain Arthropod Distribution, Abundance and Community Structure

Abstract

Distribution, abundance and species diversity of selected arthropod groups were sampled by pitfall trapping over a flooding gradient in a Midwestern river bottomland forest. Species richness increased with elevation above the floodplain, and was inversely related to flooding frequency. Areas exposed to more frequent flooding also had greater variation in species richness. Abundance of all arthropods increased with elevation over the gradient, although individual groups showed some variation in distribution patterns. Seasonality of flooding was found to influence seasonal abundance of some groups differentially. Changes in arthropod abundance and diversity (owing to reservoir construction downstream) were predicted, using data on modified flooding regimes and subsequent changes in litter habitats. Consequences of reservoir impact on arthropod communities are discussed.