WWETAC Projects

Project Title: Rapid threat assessment: genetically modified plants in wildland ecosystems

Status: Ongoing

Principal Investigators: David Harry, Outreach in Biotechnology Program, Oregon State University; Steven Strauss, Outreach in Biotechnology Program, Oregon State University; Richard Cronn, Pacific Northwest Forest Experiment Station, USDA Forest Service, Corvallis, OR

E-mail Contact: david.harry[at]oregonstate.edu;
Web: http://agsci.oregonstate.edu/orb/

Summary: Since their initial release just over 10 years ago, use of genetically modified crops, developed using recombinant DNA methods, has increased dramatically for major commodity crops such as soy beans, cotton, canola, and corn. Various concerns have been raised involving issues of human safety, ecosystem functions, and economic or political impacts. A possible consequence of such releases is longer term ecological impacts by establishment of plants (as feral escapes), or by movement of transgenes into weedy or native relatives by gene flow and interbreeding. To date, opportunities for long-term establishment of transgenes outside of agroecosystems has been relatively limited, at least in in the United States and Canada. Most GM crops (e.g., corn, soybeans) do not persist outside of cultivation, and gene flow is inhibited because GM crops have few relatives here. The escape of creeping bentgrass into the Crooked River National Grassland is a poignant example. Anticipating continued introductions and greater diversity of GM plants, we assume that the potential for inadvertent release of transgenes into wildland ecosystems will likewise increase. Wildland managers need to better understand how current policies and management practices could be affected by such releases. To what extent are wildland managers and planners anticipating the likelihood and consequence of such releases? We will conduct a rapid threat assessment (RTA) to examine potential ecological and socioeconomic impacts on wildland ecosystems resulting from an inadvertent release of genetically modified plants or transgenes. The RTA will be based upon plant groups and species with GM representatives already in the regulatory pipeline, emphasizing those further along the path to deregulation. Examples will include turf and forage grasses, trees, and other groups as appropriate (e.g., Compositae). Because of their mating system and abundance of feral or native relatives in wildland ecosystems, we feel these groups represent the most likely source of potential threats in the near term (e.g., Wipff 2002, Whitney et al. 2006, Williams 2005), and hence drive policy and regulatory decisions. The RTA will focus “on analysis of the process, stress, organism, or activity that has the potential to do harm,” (RTA framework document), which for GM plants will entail identifying GM products more likely to affect wildland ecosystems, assessing biological processes and mechanisms by which such products could directly affect wildland ecosystems, and to the extent possible, will also assess cascading impacts downward through the biosocial system.

Key issues/problems addressed: Since their initial release just over 10 years ago, use of GM crops, developed using recombinant DNA methods, has increased dramatically for major commodity crops such as soy beans, cotton, canola, and corn. Various concerns have been raised involving issues of human safety, ecosystem functions, and economic or political impacts. Several other GM crops have been commercialized (e.g., papaya, squash, alfalfa, but see Charles 2007), and a much larger number of GM products are in various stages of development, evaluation, and testing, including a number of grasses (Wipff 2002) and trees.

Genetically modified crops have been readily adopted by growers in many countries. Nevertheless, some consumers remain skeptical of GM technologies, choosing instead to purchase organic products, which in the United States preclude GM products. To meet such market demands, growers have developed various approaches to separate GM and non-GM products, including geographic isolation and buffer zones. Experience with such practices, however, have consistently demonstrated that agricultural production is inherently "leaky," leading to inadvertent release of GM plants or transgenes (e.g., through pollen or seeds). Some degree of intermixing of GM and non-GM products, variously referred to as contamination or adventitious presence, is essentially inevitable. Depending on the extent of intermixing, product specifications, and market tolerances, economic consequences may include product pricing (e.g. price premiums for organic products) or buyers may choose to reduce or cancel orders. Another possible consequence of such releases is longer term ecological impacts by establishment of plants (as feral escapes), or by movement of transgenes into weedy or native relatives by gene flow and interbreeding.

To date, opportunities for long-term establishment of transgenes outside of agroecosystems has been relatively limited, at least in in the United States and Canada. Most GM crops (e.g., corn, soybeans) do not persist outside of cultivation, and gene flow is inhibited because GM crops have few relatives here. Nevertheless, as the diversity of GM crops increases, so will the potential for establishment of transgenes outside of the agroecosystems for which they were developed. Given life histories, mating systems, and abundance of wild or feral relatives, this potential is especially great for grasses, certain trees (e.g., poplar), and perhaps composites. The escape of creeping bentgrass into the Crooked River National Grassland is a poignant example.

Anticipating continued introductions and greater diversity of GM plants, we assume that the potential for inadvertent release of transgenes into wildland ecosystems will likewise increase. Wildland managers need to better understand how current policies and management practices could be affected by such releases. To what extent are wildland managers and planners anticipating the likelihood and consequence of such releases?

Status: Initiated June 2007

Deliverables: The RTA will emphasize species groups such as grasses, composites, and forest trees. These groups have distinct life history traits, are ecologically significant in wildland ecosystems, and are included within groups of plants for which GM products are being developed and tested. In compiling our assessments we will:

  • Review the literature for agricultural ecosystems, including risk assessment.
  • Assess the existing literature to determine its adequacy for extrapolating from agroecosystems to wildland ecosystems.
  • Evaluate the potential for direct and indirect transgene impacts on various ecosystem functions. In addition to primary impacts, as appropriate, a cascading impacts approach will be used to determine secondary and tertiary impacts, following the model of Andow and Zwahlen (2006), which in turn draws heavily on expertise in ecosystem processes (Snow et al. 2005).
  • Identify ecosystem services that could be affected by such releases. This will be done by a combination of site visits and conference calls with USFS managers and planners, as deemed appropriate after consulting with USFS personnel.
  • Attend at least two national meetings, representing WWETAC's efforts to better understand and quantify potential threats from GM plants on wildland ecosystems.
  • Provide guidance to help quantify the potential magnitude of such impacts. In doing this, we will collaborate with WWETAC to identify key USFS managers and stakeholders, seeking their input to identify products and services most likely to be affected by transgene escapes. We expect two broad classes of impacts: biological and socioeconomic. To some degree, primary and secondary biological impacts can be estimated by quantifying the likelihood and magnitude of transgene escape (GM occurrence) and assessing potential biological consequences of that occurrence. Anticipating and describing socioeconomic impacts will be done to the extent possible, but is made more difficult by the fact that many of these concerns involve nonmarket values, which are challenging to quantify. For example, studies have shown that public perception of risk from GM products is heavily influenced by the context which a question is presented to a respondent (Hallman et al. 2004). We anticipate these activities to be iterative as we interact with managers and stakeholders: interactions will inform us as to which products and services are of concern, and we will inform stakeholders of biological processes affecting both occurrence and consequence of transgene escapes.

Background citations:

Andow, D.A.; Zwahlen, C. 2006. Assessing the environmental risks of transgenic plants. Ecology Letters 9: 196-214.

Charles, D. 2007. Environmental Regulation: United States courts say transgenic crops need tighter scrutiny. Science 315(5815): 1069.

Hallman, W.K.; Hebden, W.C.; Cuite, C.L.; Aquino, H.L.; Lang, J.T. 2004. Americans and GM food: knowledge, opinion and interest in 2004. Food Policy Institute Report RR-1104-007.

Jones, P. 2007. Federal courts disapprove APHIS approval procedures. Information Systems for Biotechnology News Report.

Legere, A. 2005. Risks and consequences of gene flow from herbicide-resistant crops: canola (Brassica napus L) as a case study. Pest Manag. Sci. 61(3): 292-300.

Snow, A.A.; Andow, D.A.; Gepts, P.; Hallerman, E.M.; Power, A.; Tiedje, J.M.; Wolfenbarger, L.L. 2005. Genetically engineered organisms and the environment: current status and recommendations. Ecological Applications 15(2): 377-404.

Weekes R.; Deppe, C.; Allnut, T., et al. 2005. Crop-to-crop gene flow using farm scale sites of oilseed rape (Brassica napus) in the UK. Transgenic Res. 14(5): 749-759.

Whitney, K.D.; Randell, R.A.; Rieseberg, L.H. 2006. Adaptive introgression of herbivore resistance traits in the weedy sunflower Helianthus annuus. American Naturalist 167(6): 28.

Williams, C.G. 2005. Framing the issues on transgenic forests. Nat. Biotech. 23(5): 530-532.

Wipff, J.K. 2002. Gene flow in turf and forage grasses (Poaceae). In: Scientific methods workshop: Ecological
and agronomic consequences of gene flow from transgenic crops to wild relatives, March 2002. Meeting
proceedings, 127-145.

Project ID: FY07AA13