Ecological impacts of genetically engineered crops: a case study of the Farm Scale Evaluations L. LaReesa Wolfenbarger University of Nebraska

GEO Environmental Risks and Benefits Risks of invasivenessRisks of invasiveness Non-target organism impactsNon-target organism impacts New viral diseasesNew viral diseases Reduced pesticide environmental impactReduced pesticide environmental impact Reduced rate of land conversionReduced rate of land conversion Soil conservationSoil conservation PhytoremediationPhytoremediation Source: Wolfenbarger & Phifer (2000) Science

Survival Reproduction Self-sustaining Spread and persistence Pollen flow Hybrid formation Hybrid survival Hybrid reproduction Gene introgression Pathways to invasiveness Introduction of plant

Pathways by which environmental impacts could occur Presence of transgenic crop or its transgene –plant above ground –roots –decomposing tissue –pollen drift –gene flow to wild relatives in natural ecosystem

Pathways by which ecosystem effects could occur Changes in agricultural practices associated with adoption of a transgenic crop –Pesticide use patterns –Amount of agricultural land –Tillage practices –Crop diversity/rotation

Non-target data considered in latest EPA risk assessment for Bt crops* Larval and adult honeybee Green lacewing* Ladybird beetles Parasitic Hymenoptera Monarch butterfly* Avian oral toxicity Static renewal acute toxicity, Daphnia Corn as food for farmed fish Collembola Earthworms *Standard studies based on EPA Subdivision M and/or OPPTS 885 Guidelines OVERALL Very limited evidence for toxic effects*

Monarch butterfly Risk assessment over a large geographic scale

Farm Scale Evaluations Test hypothesis that biodiversity will be the same in fields managed with GM crops compared to conventional counterparts

Farm Scale Evaluations:Why? By 1998 GE Herbicide tolerant crops have cleared most hurdles for commercialization BUT, concerns that GE Herbicide tolerant crops will reduce plant and invertebrate populations on which farmland wildlife depend

Farming in the UK Arable and pastoral farming 75% of surface area Land use continuous since 700 BC

Farmland is the environment Average farm size is 50 ha Lots of edge habitat Wildlife depends on fields and margins

Status of birds in the UK

Farm Scale Evaluations:Why? Concerns that GE Herbicide tolerant crops will reduce plant and invertebrate populations on which farmland wildlife depend

Design of the FSE Fields planted 1/2 GE, 1/2 Conventional Approx 60 fields per crop Four GE herbicide tolerant crops: beets, maize, spring oilseed rape and winter rapeseed

Sites distributed over the UK

Design of the FSE Fields planted 1/2 GE, 1/2 Conventional Approx 60 fields per crop Four GE herbicide tolerant crops: beets, maize, spring oilseed rape (canola) and winter rapeseed Measure biodiversity within fields and at margins Biodiversity: weeds, seeds and inverts

Habitats sampled

Why not measure birds? Plants and inverts respond directly to herbicide management Conclusion of no effect more robust Model effect on birds

Herbicide practices during FSE GE crop Fewer applications, later timing, weed cover variability

Herbicide practices: Maize GE crop More weed cover in GE half of field

Herbicide practices: Oilseed rape More weed cover with conventional cropping GE cropping: later, fewer

Results: 8 papers, >100 Tables and figures

Andow’s cheat sheet for results

What do we do with this?

Complications to maize interpretations? Atrazine banned in 2003

Largest differences due to crop and season

Status of birds in the UK

How was information from FSE used?

Policy results Advisory committee recommends ban on GE HT beets and oilseed and approval of GE HT maize

Recommendations to parliament oppose EU approval for the commercial cultivation of the GM beet and oilseed rape as grown in the FSE trials only allow the commercial cultivation of the GM maize in the FSE trials if restrictions are imposed on its EU marketing consent to limit herbicide use March 2004

March 2005 BayerCropScience withdraws its plans to cultivate its approved GE corn “…too many demands”

November 2005 No GE crops grown in the UK None expected before 2008 Approval for use of GE crops in feed is occurring

And, the latest…. Swiss citizens are not prepared to sell their souls and convictions to satisfy their consumer tastes. Le Matin on approval of a five-year ban on GM foods, 28 November 2005