County Wildife Site Criteria for Cornwall Appendices

ARABLE FIELD MARGINS PHTGeneral DescriptionThe term "arable field margin" refers to strips of land lying between arable crops and the fieldboundary, and extending for a limited distance into the crop, which are deliberately managed tocreate conditions which benefit key farmland species.Arable field margins provide nesting and feeding sites for many birds. Species of butterflies,grasshoppers, and plant bugs are associated with such sites. Even excluding soil invertebrates, microorganismsand transients, some 2000 species of invertebrate are commonly found in cereal fieldsalone.Even more dependent on arable field margins are the rare arable flowers. Threatened and importantspecies from these margins include pheasant's eye Adonis annua, cornflower Centaurea cyanus,broadleaved spurge Euphorbia platyphyllos, corn parsley Petroselinum segetum, shepherd’s-needle Scandixpecten-veneris and narrow-fruited cornsalad Valerianella dentata.National ContextArable land covers about 60 000 km 2 in Great Britain (defined as total crops plus bare fallow plusgrassland less than five years old).The margins of arable fields could be managed in ways which would benefit wildlife, without havingserious detrimental effects on the remaining cropped area. Estimating average national field size to be12 ha suggests that there are about 800 000 km of arable field edge in the UK. If all such boundariesincluded a 6 m managed margin, some 400 000 ha of land would be brought into sensitivemanagement.The extent of this habitat in Cornwall is not currently known.For this habitat we will take all areasAppendix 4 - Information Relating to Priority Habitat TypesCounty Wildlife Sites Criteria