The microspatial distribution of beetles (Coleoptera) on exposed riverine sediments (ERS)

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

Abstract

Exposed Riverine Sediments (ERS) are often characterised by a high diversity of microhabitats due to strong lateral gradients in temperature, humidity, inundation frequency and availability of aquatic food resources and to variations in the degree of vegetation cover, sediment size and sorting. This variation, potentially in combination with interspecific competitive interactions, is thought to drive the microspatial distribution of ERS invertebrates. This research investigated the microspatial distribution of six ERS specialist beetles across three discreet patches of ERS. In particular it examined the temporal stability of species distributions, and their spatial association with environmental variability and other species. The research used a grid of 204 modified dry pitfall traps over six sampling periods in which weather conditions and water levels were stable, and used the Spatial Analysis by Distance IndicEs (SADIE) method to test the significance of spatial distributions and associations. Strong and significant microspatial zonation was observed for all species, and with few exceptions these distributions were remarkably stable across the study period. This zonation was mainly associated with elevation and proximity to the water, and several species were consistently spatially associated or disassociated with one another. This suggests that laterally more extensive patches of ERS support more species. Operations that reduce the size of ERS patches, such as channelisation, aggregate extraction and regulation are therefore likely to reduce ERS invertebrate diversity.

Details

Original languageEnglish
Pages (from-to)479-487
Number of pages9
JournalEuropean Journal of Entomology
Volume104
Issue number3
Publication statusPublished - 1 Jul 2007

Keywords

  • microdistribution, Elateridae, Spatial Analysis by Distance Indices (SADIE), river Severn, exposed riverine sediments, carabidae, riparian, pitfall trapping, hydroecology, habitat preference