On the rationale and interpretation of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

• Published in: Philosophical transactions of the Royal Society of London. Series B. Biological sciences 2003-11, Vol.358 (1439), p.1779-1799
• Main Authors: Squire, G. R., Brooks, D. R., Bohan, D. A., Champion, G. T., Daniels, R. E., Haughton, A. J., Hawes, C., Heard, M. S., Hill, M. O., May, M. J., Osborne, J. L., Perry, J. N., Roy, D. B., Woiwod, I. P., Firbank, L. G.
• Format: Article
• Language: English
• Subjects: Agriculture - methods; Arable; Beta vulgaris; Beta vulgaris - physiology; Biodiversity; Brassica napus; Brassica napus - physiology; Crop management; Crop science; Crops; Food Chain; Food crops; Functional Groups; Genetically Modified Herbicide-Tolerant Crops; Herbicides; Herbicides - metabolism; Invertebrates; Models, Biological; Oilseeds; Pesticides; Plants; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - physiology; Seedbank; Seeds - physiology; Transgenic plants; United Kingdom; Weeds; Zea mays; Zea mays - physiology
• ISSN: 0962-8436; 1471-2970
• DOI: 10.1098/rstb.2003.1403

Farmland biodiversity and food webs were compared in conventional and genetically modified herbicide-tolerant (GMHT) crops of beet (Beta vulgaris L.), maize (Zea mays L.) and both spring and winter oilseed rape (Brassica napus L.). GMHT and conventional varieties were sown in a split-field experimental design, at 60-70 sites for each crop, spread over three starting years beginning in 2000. This paper provides a background to the study and the rationale for its design and interpretation. It shows how data on environment, field management and the biota are used to assess the current state of the ecosystem, to define the typical arable field and to devise criteria for selecting, sampling and auditing experimental sites in the Farm Scale Evaluations. The main functional and taxonomic groups in the habitat are ranked according to their likely sensitivity to GMHT cropping, and the most responsive target organisms are defined. The value of the seedbank as a baseline and as an indicator of historical trends is proposed. Evidence from experiments during the twentieth century is analysed to show that large changes in field management have affected sensitive groups in the biota by ca. 50% during a year or short run of years - a figure against which to assess any positive or negative effects of GMHT cropping. The analysis leads to a summary of factors that were, and were not, examined in the first 3 years of the study and points to where modelling can be used to extrapolate the effects to the landscape and the agricultural region.