S5RVAC2P

2763

5 janvier 2021 17:06

5 janvier 2021 17:06

Field boundaries and ®elds on 22 pairs of organic and conventional farms in England and Wales were surveyed over three breeding seasons (April±July) and two autumn (September±November) and winter (December±February) periods in order to ascertain whether organic and conventional farms di€ered in the size and diversity of their associated bird populations. Species diversity was signi®cantly higher on organic farms in the 1994 breeding season, but in no other year or season. Of 18 species, eight showed a signi®cantly higher density on organic ®eld boundaries in at least one season/year, with a greater number of signi®cant results being detected in the autumn. There were very few signi®cant di€erences in bird density in ®elds outside the breeding season. The density of breeding skylarks Alauda arvensis, the principal ®eld nesting species, was signi®cantly greater on organic farms in one breeding season. Hedges tended to be higher and wider, ®eld boundaries tended to have more trees and ®eld sizes tended to be smaller on organic farms. Canonical correspondence analysis indicated that components of habitat structure were important in explaining di€erences in bird density between farm types for certain species. # 1999 Elsevier Science Ltd. All rights reserved.

None

• AB - Modalité bio
• FREDO durabilité
• FREDO environnement
• GEO Royaume-Uni
• biodiversité
• canonical correspondence analysis
• comparaison
• habitat structure
• hedgerow
• organic farming
• species density

Biological Conservation

88

307-320

06/1999

1 juin 1999

10.1016/S0006-3207(98)00124-4 Le DOI est une URL unique de référencement d'une publication. Il est donc plus fiable et permanent qu'une URL classique

00063207 L’ISSN est un code de 8 chiffres servant à identifier les journaux, revues, magazines, périodiques de toute nature et sur tous supports, papier comme électronique.