Community response to transgenic plant release: predictions from British experience of invasive plants and feral crop plants


  • Mark Williamson is a population ecologist with a particular interest in invasions. He has served on all the British committees concerned with the regulation of the releases of GMOs since they started in 1986. He has had contracts from the Department of the Environment, the Health and Safety Executive, The Commission of the European Communities (DGXI and DGXII) and the Organisation for Economic Cooperation and Development (DSTI and Environment) in this area.

Department of Biology, University of York, York YO1 5DD, UK. Fax 0904 43 28 60.


The ten-ten rule can be used to predict the community consequences of releasing GMOs. This, combined with data on the feral state of British crop plants, predicts that almost all GMOs will become at least casual, that more than 10% will establish, and about 10% of those will become pests. Which constructs will fall into which category cannot be predicted from their characters. In particular, Baker characters have no predictive value for weediness. The fourteen most troublesome invasive plant pests show a remarkably diverse set of characters. GMOs, being mainly derived from crop plants, and in some cases with genes that are likely to enhance survival, can be expected to have an appreciable effect on nonagricultural ecosystems, once a range of different constructs have been released. Familiarity is unlikely to be an effective defence against new ecological effects.