Over hundred ecologically oriented scientists met in Prague, Czech Republic, on November 26 - 29, 2003, to evaluate ecological impact of the genetically modified (GM) crops. Results of current investigations were summarized in more than seventy contributions. One day was devoted to work in small groups of experts that dealt with specific methodological questions. And at the end of the meeting, the participants discussed the role of IOBC (International Organization for the Biological and Integrated Control of Noxious Animals and Plants) in developing the methods of assessing environmental impacts of GM crops and other agricultural practices.
Investigations on GM crops, which had been performed independently in a number of European countries, failed to disclose any effect that can be classified as environment-damaging on the basis of current criteria. Most information was obtained on so called Bt-maize that carries Bacillus thuringiensis gene for an insect-specific toxin. It was repeatedly emphasized at the meeting that the fears of ecological damage caused by GM crops are not justified. To the contrary, the European trials and the practical experience overseas unequivocally show that GM crop planting brings about reductions in the use of pesticides and fuel and thereby lowers environmental stress. Concurrent yield increase offers a chance to allot some of arable land to other uses, including restoration of original habitats with full scale nature protection.
It must be noted, however, that any agricultural activity has ecological consequences. The very origin of agriculture, i.e. a change from wild plant collection to their planting, was an intervention with natural processes. The diversity of organisms was reduced and their assemblages altered in the newly created agro-ecological systems. The deterioration of biodiversity has been accelerated with the use of fertilizers and pesticides, mechanization, reduced of crop rotation, and other agro technologies. Only in last few decades it has been realized that continuation of reckless intensification of agriculture may lead to ecological collapse in the fields and irreparable nature damage. Even the most environmentally friendly methods used in organic gardening have ecological impacts that ought to be evaluated from the viewpoints of sustainable agriculture and nature conservation. Such evaluations, however, are cumbersome and appropriate methodology is still lacking. Most experience has been gained in ecological studies with GM crops. At present, we know much more about possible risks associated with their planting than we know about the impacts of pesticides, fertilizers, and novel agro technologies. Ecological impact of new cultivars obtained with classical breeding methods has not so far been considered at all.
The use of GM crops may accelerate some processes that are associated with agriculture. Remarkable is the decline of weeds that has been followed in detail in England but apparently reflects situation in the whole of Europe. The production of seeds by weeds declines in our fields annually by 3%. This is good news for intensive agriculture but not for many organisms that depend on the seeds - from hardly visible insects to birds. The decline of weed seed banks is a long process (current level is about a quarter of that hundred years ago) with unknown final consequences. The research on herbicide-tolerant GM crops indicated that their planting may accelerate the decline. Reconciliation of the needs of competitive agriculture with the concepts of nature conservation becomes more imperative than ever before and goes far beyond the use of GM crops.
Most risks associated the plantation of GM crops are similar to the risks of other agricultural innovations and should be evaluated in this context. The risks must be assessed on the case basis, i.e. separately for each crop, each type of genetic manipulation, and in some instances also in respect to the geographic region. Participants of the meeting agreed on the need to elaborate risk assessment methods that should be applied to all new agro technologies, GM crops included. The crops currently considered for the plantation in Europe do not seem to present a serious risk but their possible ecological impact ought to be followed further after their introduction into practical agriculture.
More information can be obtained at
or by contacting
Prof. RNDr. František Sehnal, CSc.
Institute of Entomology, Czech Academy of Sciences
tel.: 385 310 350