Henrik Smith
Professor
Consequences of organic farming and landscape heterogeneity for species richness and abundance of farmland birds.
Author
Summary, in English
It has been suggested that organic farming may benefit farmland biodiversity more in landscapes that have lost a significant part of its former landscape heterogeneity. We tested this hypothesis by comparing bird species richness and abundance during the breeding season in organic and conventional farms, matched to eliminate all differences not directly linked to the farming practice, situated in either homogeneous plains with only a little semi-natural habitat or in heterogeneous farmland landscapes with abundant field borders and semi-natural grasslands. The effect of farm management on species richness interacted with landscape structure, such that there was a positive relationship between organic farming and diversity only in homogeneous landscapes. This pattern was mainly dependent on the species richness of passerine birds, in particular those that were invertebrate feeders. Species richness of non-passerines was positively related to organic farming independent of the landscape context. Bird abundance was positively related to landscape heterogeneity but not to farm management. This was mainly because the abundance of passerines, particularly invertebrate feeders, was positively related to landscape heterogeneity. We suggest that invertebrate feeders particularly benefit from organic farming because of improved foraging conditions through increased invertebrate abundances in otherwise depauperate homogeneous landscapes. Although many seed-eaters also benefit from increased insect abundance, they may also utilize crop seed resources in homogeneous landscapes and conventional farms. The occurrence of an interactive effect of organic farming and landscape heterogeneity on bird diversity will have consequences for the optimal allocation of resources to restore the diversity of farmland birds.
Department/s
- Biodiversity
- BECC: Biodiversity and Ecosystem services in a Changing Climate
- Biodiversity and Conservation Science
Publishing year
2010
Language
English
Pages
1071-1079
Publication/Series
Oecologia
Volume
162
Issue
4
Document type
Journal article
Publisher
Springer
Topic
- Ecology
Status
Published
Research group
- Biodiversity and Conservation Science
ISBN/ISSN/Other
- ISSN: 1432-1939