The influence of hedgerows on coleopteran distributions: results from a multi-field sampling study.

Abstract

Understanding the distribution patterns and scale of patchiness of key beneficial species in fields and field margins, and the spatial and temporal stability of these patterns, can provide valuable information on species' ecological requirements. However, previous studies of spatial distribution have focussed on patterns within single fields, although aggregations may extend beyond boundaries and, for some species, may be influenced by them. To investigate this, the distribution of Coleoptera was monitored across 66 ha of arable land encompassing six fields and their boundaries. Sampling was carried out using two pitfall traps at each of 973 locations arranged in a regular grid pattern on four occasions between May and July 2000. The distribution of some Coleoptera was visualised using GIS mapping and analysed using SADIE to identify patches and gaps of significant size. Evidence of aggregation is presented for total carabid species number, Bembidion lampros, Pteroslichus madidus and Philonthus cognatus. The highest carabid diversity was found near to field boundaries. For some patches their extent was confined by the field boundaries. The experiment formed part of a new MAFF SAPPIO project '3D Farming - making biodiversity work for the Farmer.'