Organic farmers make a difference for English wildlife

3 August 2005

The largest and most comprehensive study of organic farming to date, published today in the Royal Society Journal Biology Letters by a team including scientists from Oxford University, shows conclusively that organic farms provide greater benefits for a range of wildlife including wild flowers, beetles, spiders, birds and bats than their conventional counterparts.

Scientists from the British Trust for Ornithology (Thetford), the Centre for Ecology & Hydrology (Lancaster) and the Wildlife Conservation Research Unit (University of Oxford) have spent five years studying the differences between matched pairs of organic and non-organic cereal-producing farms in lowland England.

The study showed that organic farming systems provide greater potential for biodiversity than their conventional counterparts, as a result of greater variability in habitats and more wildlife-friendly management practices, which resulted in real biodiversity benefits, particularly for plants.

A huge amount of fieldwork was involved in the study – hedges were measured, beetles, spiders, birds and wildflowers were counted, farmers were questioned and bats were detected. The study produced many significant results, including:

• Organic crops contain almost twice as many types of plant species (85% more).
• There were more spiders (17% more), birds (5%) and bats (33%) too but the effects were not as significant as for plants.
• There is more grassland within organic farms and higher densities of hedges.
• Fields are smaller and hedges thicker on organic farms.
• Organic farmers sow their crops later and cut their hedges less frequently.

Many previous studies that claim to demonstrate that organic farming benefits biodiversity are poorly designed, limited to one group of animals or plants, or local in scale. In this integrated study, covering 160 farms from Cornwall to Cumbria, the authors have shown that the organic farms supported higher numbers of species and overall abundance across most groups of plants and animals.

Professor David Macdonald of Oxford University’s Wildlife Conservation Research Unit (WildCRU), whose team monitored beetles, spiders and bats as part of the study, said: ‘Because so much of the countryside is farmland, the future of farmland holds the key to wildlife conservation in the UK. There has never been a more exciting time in this sphere, with radical changes in the Common Agricultural Policy, and more to come. This new future must be based on evidence, and our large-scale, collaborative, inter-disciplinary study has yielded just the sort of evidence that the policy-makers, and the public, need.’

Dr Rob Fuller, Director of Habitat Research for the British Trust for Ornithology (BTO), and lead author of the paper said: ‘Organic farms clearly have positive biodiversity effects for wild flowers. However, if they are to provide benefits on the same scale for species that need more space, like birds, we either need the farms to be larger or for neighbouring farms to be organic too. Currently, less than 3% of English farmland is organic so there is plenty of scope for an increase in area. Such an increase would help to restore biodiversity within agricultural landscapes.’

For more information contact the Oxford University Press Office on 01865 280534 or email press.office@admin.ox.ac.uk or Graham Appleton at BTO on 01842 750050/0797 4668503 or email graham.appleton@bto.org. Images are available from images@bto.org.

Notes to Editors:

• ‘Benefits of organic farming to biodiversity vary among taxa’ by R.J. Fuller, L.R. Norton, R.E. Feber, P.J. Johnson, D.E. Chamberlain, A.C. Joys, F. Mathews, R.C. Stuart, M.C. Townsend, W.J. Manley, M.S. Wolfe, D.W. Macdonald and L.G. Firbank is published in Biology Letters on 3 August 2005.
• The research was carried out by scientists from the British Trust for Ornithology (Thetford), the Centre for Ecology & Hydrology (Lancaster) and the Wildlife Conservation Research Unit (University of Oxford). The study was funded by Defra. Bird research and habitat mapping were carried out by BTO scientists, whilst CEH staff were responsible for plant surveys and interactions with farmers, and Oxford University researchers monitored beetles, spiders & bats. Advice and assistance was received from the Royal Agricultural College (Cirencester), Elm Farm Research Centre (Newbury) and the Soil Association.
• The mission of the Wildlife Conservation Research Unit (WildCRU) is to achieve practical solutions to conservation problems. This is done through original scientific research of the highest calibre, and, vitally, the training of committed conservation scientists to conduct research, and to put scientific knowledge into practice. WildCRU participates in the implementation of many conservation projects and embraces the need to educate and involve a wider public to achieve lasting solutions. www.wildcru.org/
• The British Trust for Ornithology (BTO) has existed since 1933 as an independent, scientific research trust, investigating the populations, movements and ecology of wild birds in the British Isles. The BTO’s speciality is the design and implementation of volunteer wild bird surveys. Its partnership between a large number of volunteers and a small scientific staff has proved to be a powerful, productive and cost-effective way of monitoring wild birds. www.bto.org/
• Biology Letters is a primarily online, peer-reviewed journal that publishes short, high-quality papers from across the biological sciences. It is published by the Royal Society, the UK's national academy of science. http://www.pubs.royalsoc.ac.uk/biologyletters.shtml