The potential of grass field margin management for enhancing beetle diversity in intensive livestock farms

Abstract

Summary1. Declining populations of UK grassland flora and fauna have been attributed to intensification of agricultural management practices, including changes in cutting, fertilizer, grazing and drainage regimes. We aimed to develop field margin management practices that could reverse declines in intensively managed grassland biodiversity that would have application in the UK and Europe. Here we focus on one aspect of grassland biodiversity, the beetles. 2. In four intensively managed livestock farms in south-west England, 10-m wide field margins in existing grasslands were managed to create seven treatments of increasing sward architectural complexity. This was achieved through combinations of inorganic (NPK) fertilizer, cattle grazing, and timing and height of cutting. To examine the potential influence of complexity on faunal diversity, beetles were identified to species level from suction samples taken between 2003 and 2005, and their assemblage structure was related to margin management, floral assemblages and sward architecture. 3. Beetle abundance, and species richness and evenness were influenced by margin management treatment and its interaction with year. Correlations with sward architecture and the percentage cover of dominant forbs and grasses were also found. Functional groups of the beetles showed different responses to the management treatments. In particular, higher proportional abundances of seed/flower-feeding guilds were found in treatments not receiving NPK fertilizer. 4. The assemblage structure was shown to respond to margin management treatments, sward architecture and the percentage cover of dominant forbs and grasses. The most extensively managed treatments were characterized by distinct successional trajectories from the control treatment. 5. Synthesis and applications. This study provides management options suitable for use within agri-environment schemes intended to improve faunal diversity associated with intensively managed lowland grasslands. Field margins receiving either no management or a single July silage cut were shown to support greater abundances and species richness of beetles, although subtler modifications of conventional management may also be beneficial, for example the absence of NPK fertilizer while maintaining grazing and silage cutting systems.

A spatial scale assessment of habitat effects on arthropod communities of an oceanic island

“…Indeed, elsewhere, traditionally managed semi-natural pastures are also recognized for their value in conserving native species (e.g. Woodcock et al, 2007). The correlation values also supported this point of view.…”

Vulnerability of Pollination Ecosystem Services

“…Human-altered regional habitat can also be used to support pollinator populations, if managed appropriately. Minimizing grazing and cutting of grasslands can increase regional floral resource availability (Duffey et al 1974;Kruess and scharntke 2002) and insect nest site availability (Morris 2000;Woodcock et al 2007). Pasture that is infrequently grazed can provide bee populations with important floral and nesting resources (e.g., Morandin et al 2007), and the reduction of fertilizer application, in conjunction with reduced grazing, has been shown to provide improved habitat for a number of butterfly species (e.g., Erhardt 1985).…”

Do field margin characteristics influence songbird nest‐site selection in adjacent hedgerows?

“…Data were collected within a replicated experiment of 'grass ley' and 'sown' field margins on four livestock farms in southwest England, each farm separated by at least 8 km. Field work took place in the final year (2006) of a four-year study investigating potential benefits to biodiversity (plants, invertebrates and birds) of increasing sward architectural complexity in margins of grass fields (Pilgrim et al 2007, Woodcock et al . 2007.…”

“…Margins were 10 m wide, 50 m long and located adjacent to existing hedgerows. All fields were lowland improved grasslands classified as speciespoor MG7 Lolium perenne L. leys (Rodwell 1992 swards from intensive to extensive management, across which plant species richness, vegetation structural complexity, and abundance and diversity of invertebrates increased (Woodcock et al 2007). The sown treatments were also designed to provide high seed resource habitats.…”