Spatial distribution patterns of predatory arthropods within an English hedgerow in early winter in relation to habitat variables
Agriculture Ecosystems & Environment
The overall objective of this study was to investigate small-scale spatial distributions of invertebrates within a continuous length of hedgerow. The early winter distributions of three predatory arthropod taxa, Staphylinidae, Carabidae and Araneae, were studied within a single hedgerow, in relation to a number of biotic and abiotic environmental variables. Vertical distribution patterns were marked and contrasting between taxa, with spiders found predominantly in the shrubby hedge foliage and hedge-base vegetation, carabids in both leaf litter and soil (0-10cm) and staphylinids in the 0-10cm soil layer. Hedge orientation and biomass of hedge-base vegetation were implicated as important factors influencing arthropod abundance. Data on individual carabid species showed some differential habitat preferences, as well as differences in the degree of spatial variability. Canonical correspondence analysis of hedge-base carabids showed strong 'field' differences between the two sides of the hedgerow. Soil moisture content and monocotyledon biomass also explained a significant proportion of the observed variation in carabid species composition. These results may reflect differing overwintering site selection between carabid species. The abundance of predatory arthropods was highly variable between micro-sites along the hedgerow, with evidence of overwintering aggregations. This variability has implications for the sampling regimes of both small and larger scale hedgerow studies. (C) 2002 Elsevier Science B.V. All rights reserved.
Author(s): Maudsley, M; Seeley, B; Lewis, O
Journal: Agriculture Ecosystems & Environment