October 17, 2003
UK Research Proves GM Crops Could Cause Significant Reduction in Biodiversity of Arable Fields
According to the results from the 3-year UK government funded trails, growing genetically modified (GM) crops could cause a significant reduction in the biodiversity of arable fields.
Yesterday, Royal Society released the long-awaited results of the Farm Scale Evaluations of GM herbicide-tolerant spring oilseed rape, sugar beet and maize.
The trials found that the number of weeds and dependent insects was significantly lower in GMHT (genetically modified herbicide tolerant) rape and beet than in their conventional counterparts.
In contrast, GMHT maize showed the opposite effect, according to the eight papers published.
Scientists involved in the studies put this down to the widespread use of persistent herbicides in conventional maize, bringing about lower weed burdens.
Co-ordinator of the FSE project Les Firbank, from the Centre for Hyrdrology and Ecology confirmed there were "significant differences" between the conventional and GM crops in trials.
"The study emphasises the importance of the weeds growing among crop plants in sustaining natural communities within, and adjacent to, farmer's fields," said Dr Firbank.
"One of the key points to remember is that the results are only applicable to the three crops studied, and only under the regimes of herbicide usage which were employed."
The trials were carried out due to concerns raised over what effects growing GM crops would have on farmland biodiversity.
The Advisory Committee on Releases to the Environment recommended the three-year trial programme to assess whether wider use of the non-selective herbicides in GM systems would reduce numbers of weeds and invertebrates.
"Although this has been going on in cropped fields in Britain for many decades, it could be accelerated by the management associated with these particular crops," pointed out a statement from the Royal Society.
Due to the lower weed population in GMHT beet and oilseed rape, invertebrate species were also found to be lower.
"Smaller numbers of butterflies were recorded in GMHT oilseed rape and smaller numbers of bees, butterflies and Heteroptera ('true bugs') were found in GMHT beet," noted the research papers.
Again, the opposite was found in GMHT maize crops.
But in all GMHT crops there were significantly more detritivores, which feed on dead and decaying weeds.
Researchers attribute this phenomenon to the weeds that are removed later in the season under the GM system.
