Agriculture, Ecosystems and Environment 139 (2010) 181–186 Contents lists available at ScienceDirect Agriculture, Ecosystems and Environment journal homepage: www.elsevier.com/locate/agee Impact of habitat type and landscape structure on biomass, species richness and functional diversity of ground beetles B.A. Woodcock a,∗ , J. Redhead a , A.J. Vanbergen b , L. Hulmes a , S. Hulmes a , J. Peyton a , M. Nowakowski c , R.F. Pywell a , M.S. Heard a a NERC Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, UK b NERC Centre for Ecology & Hydrology, Bush Estate, Penicuik, Edinburgh EH26 0QB, UK c Wildlife Farming Company, Chesterton, Bicester, Oxfordshire OX26 1UN, UK article info Article history: Received 10 March 2010 Received in revised form 27 July 2010 Accepted 27 July 2010 Available online 19 August 2010 Keywords: Carabidae Ecosystem services Local habitat type Landscape heterogeneity Tussock Grass abstract This study investigated how local habitat type and landscape structure affects the biomass, species rich- ness and functional diversity of ground beetles sampled from a 1000 ha UK arable farm. At a local scale habitat type was either crop (winter wheat and oilseed rape) or one of five field margin habitats. Sur- rounding each of these sampling areas, landscape structure was defined using remote sensed data from Specim AISA Eagle (400–970 nm) and Hawk (970–2450 nm) hyperspectral sensors. Ground beetles were divided into predatory and phytophagous trophic levels. Local habitat type only affected phytophagous ground beetle biomass, which was lowest within crops. Total biomass of predatory beetles was nega- tively correlated, and species richness positively correlated, with landscape habitat diversity. Only the functional diversity of predatory ground beetles responded to landscape structure, showing positive cor- relations with the proportion of Tussock Grass field margins. Predatory ground beetles show a greater dependence on landscape structure than phytophagous species, a response that is attributed to their high mobility needed for movement between dynamically variable food resources. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Three broad characteristics of generalist predator assemblages are likely to influence the provision of biological control. These are overall abundance/biomass, species richness and functional diversity (Sih et al., 1998; Symondson et al., 2002; Hooper et al., 2005; Ives et al., 2005; Díaz et al., 2006). The importance of increased numbers of predatory invertebrates (either in terms of abundance, biomass or density) is a basic tenet of biological control (Kruess and Tscharntke, 1994; Symondson et al., 2002). More individual predators result in greater overall consumption of pest herbivores, with predators often spatially tracking the populations of pest species (Symondson et al., 2002; Lavandero et al., 2004). While the importance of predator numbers alone may be intuitively obvious, the effect of increasing the numbers of predator species on the control of pest populations is often more complex. Increased predators species richness can result in emergent non-additive effects that increase overall rates of prey consumption (Sih et al., 1998; Ives et al., 2005; Snyder et al., 2006). Such ‘over yielding’ of prey typically occurs where preda- ∗ Corresponding author. Tel.: +44 0 1491692415; fax: +44 0 1491692424. E-mail address: BAWood@ceh.ac.uk (B.A. Woodcock). tors show limited niche overlap, reducing the effectiveness of behavioural escape mechanisms of common prey species (Sih et al., 1998; Schmitz, 2007). This positive effect of predator species richness on pest control is one of the main motivations behind the creation of non-cropped field margins in association with crops (Marshall, 1988; Thomas et al., 1991, 1992). Functional diversity measures the extent to which individual species trait character- istics differ between all species within an assemblage (Hooper et al., 2005; Petchey and Gaston, 2006). Predator assemblages show- ing high functional diversity are likely to have greater levels of complementarity in traits associated with prey capture and con- sumption (Petchey and Gaston, 2002). Such complementarity could increase rates of resource capture, i.e. the consumption of pest invertebrates (Hooper et al., 2005; Díaz et al., 2006). Conversely, assemblages with low functional diversity may be more likely to show niche overlap, increasing the chances of interference compe- tition and so reducing the potential for biological control (Schmitz, 2007). In Europe and other temperate regions, ground beetles are important components of natural enemy assemblages (Thiele, 1977; Sunderland et al., 1987; Thomas et al., 1992). This study con- trasts how ground beetle biomass, species richness and functional diversity respond to local habitat type and landscape structure. Local habitat type refers to the immediate area surrounding a 0167-8809/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.agee.2010.07.018