Introduction Directory UMM :Data Elmu:jurnal:A:Agriculture, Ecosystems and Environment:Vol81.Issue1.Oct2000:

Agriculture, Ecosystems and Environment 80 2000 227–242 Linear features and butterflies: the importance of green lanes John Dover a,b,∗ , Tim Sparks c , Sue Clarke b , Kay Gobbett b , Sarah Glossop d a Myerscough College, Bilsborrow, Preston PR3 0RY, UK b The Game Conservancy Trust, Fordingbridge SP6 1EF, UK c NERC Institute of Terrestrial Ecology, Monks Wood, Abbots Ripton PE17 2LS, UK d Department of Environmental Management, University of Central Lancashire, Preston PR1 2HE, UK Received 31 March 1999; received in revised form 16 December 1999; accepted 21 February 2000 Abstract Green lanes are unmetalled tracks between fields of variable width, which may be sunk below or raised above field level, and bounded on both sides by ‘grass’ banks, hedgerows or dry-stone walls. In the UK they have no unique planning status and have been overlooked as discrete landscape elements. Green lanes were surveyed for butterflies in 1997 on lowland arable farmland on the Traffordnorth Cheshire border Warburton and on upland grassland in the Yorkshire Dales Ribble Valley. At the lowland site the green lanes were bounded by vegetation and were compared with grass banks and single hedgerow field boundaries; at the upland farm, the green lanes were bounded by dry-stone walls and were compared with grass banks and single dry-stone walls. Data from earlier work on a largely arable farm Manydown in Hampshire in 1987 and 1988 were re-analysed to make comparisons between a green lane, the rides and glades of two coppiced woodlands, and the grass banks and single hedgerows surrounding arable fields. Green lanes, whether bounded by vegetation or stone were superior to other common farmland biotopes with the exception of woodland, in terms of both butterfly abundance and species richness. Multiple regression of the Warburton data indicated the importance of green lanes, adjacent habitat type, and nectar sources for species richness and butterfly abundance. The interior of green lanes had lower windspeeds, and more bramble nectar sources than hedgerows or grass banks. By their nature they occupy a larger area of uncropped land, and are subject to a reduced disturbance regime and reduced inputs of agrochemicals and fertilisers. Their value as biodiversity reservoirs in intensively managed land is likely to be high. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Biodiversity; Butterfly abundance; Field margins; Nectar plants; Woodland; United Kingdom

1. Introduction

Information on butterfly distribution and abundance in farmland has increased in recent years in respect of field boundary habitats, field margins and manip- ulation of the crop Dover, 1989; 1990, 1991, 1994, ∗ Corresponding author. Tel.: +44-1995-640611; fax: +44-1995-640842. E-mail address: jdovermyerscough.ac.uk J. Dover 1996, 1997; Dover et al., 1990, 1997; Feber et al., 1994, 1996, 1997; Feber and Smith, 1995; Sparks and Parish, 1995; de Snoo, 1996; Sparks et al., 1996. Most of these studies relate to the typical habitats which sur- round arable crops such as woodland edge, hedgerows, and grass banksverges; other habitats such as rail- ways and wetlands are cited less frequently. Recently, Dover et al. 1997 presented some evidence that the tracks between fields colloquially known as ‘green lanes’ Belsey, 1998 might be important for wildlife 0167-880900 – see front matter © 2000 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 7 - 8 8 0 9 0 0 0 0 1 4 9 - 3 228 J. Dover et al. Agriculture, Ecosystems and Environment 80 2000 227–242 habitat, in a re-analysis of data from the Butterfly Mon- itoring Scheme transect for Woodwalton Farm. This followed from the suggestion of Dover 1996 that the shelter afforded by green lanes composed of a double line of hedges would be superior to single hedgerows. The definition of what constitutes a green lane is a difficult one Belsey, 1998, as the width of the track of a green lane may vary and be bounded by banks, ditches, hedges, scrub or dry-stone walls. The track itself should be unmetalled, but that does not exclude the addition of hard-core to improve traction for farm machinery. The variability of the boundary features and the exact nature and disturbance regime includ- ing cutting of the track are likely to impinge on the value of green lanes as wildlife habitat and hence the number, type and abundance of species within them. This paper addresses the question of whether green lanes are superior, in terms of adult butterfly abun- dance and species richness, to simpler linear features such as hedgerows, grass banks and drystone walls.

2. Methods