© jens
christiansen
In 1999, the UK government asked a
consortium of researchers to investigate
how growing GM crops might affect the
abundance and diversity of farmland
wildlife compared with growing conventional
varieties of the same crops. The results
were intended to help the government decide
whether to allow such GM crops to be grown
commercially in the UK , but were never
meant to be the sole factor in this
decision. The researchers studied three
genetically modified herbicide-tolerant
(GMHT) and conventional crops: beet,
oilseed rape and maize. The effects of
these crops on weeds and invertebrates were
investigated across the UK for three
growing seasons during the period
2000-02.
mixed results for butterflies
and bees
The British researchers found that
growing conventional beet and spring
oilseed rape was better for many groups of
wildlife than were the GM equivalents.
There were more insects, such as
butterflies and bees, in and around the
conventional crops because there were more
weeds to provide food and cover. There were
also more weed seeds; important in the
diets of some animals, particularly birds.
The long-term decline in weed seed banks is
predicted to increase, causing “accelerated
species decline” under GMHT crop
regimes.
However, GMHT maize was better for many
groups of wildlife than conventional maize.
There were more weeds in and around the
GMHT crops, more butterflies and bees
around at certain times of year, and more
weed seeds. In general, conventional
oilseed rape and beet fields were the
richest in flora and fauna, with
conventional maize crops the poorest.
Effects were explained by the different
herbicide regimes and were consistent
between sites, farms, years and different
initial levels of weeds
skylark extinct in 20
years?
If these trends are maintained under
widespread GMHT cropping, then the present
herbicide regimes associated with GMHT beet
and spring oilseed rape might exacerbate
long-term declines of weeds, including
species that are important food resources
for many invertebrate, small mammal and
bird species. A modeling exercise published
by the Department for Environment, Food and
Rural Affairs three days before the release
of the farm-scale evaluation results
predicted that the level of weed control
possible if GM oilseed, rape and GM beet
were commercialized would lead to the
skylark becoming extinct in two decades due
to lack of food. Two common weeds and
important sources of food for wildlife, fat
hen and chickweed, could disappear in half
a century.
In contrast, these same weeds might
increase in abundance following a shift
from conventional to GMHT maize cropping
due to the greater weed control exerted by
conventional herbicide regimes compared to
those used with the GMHT crops. However,
the validity of the maize trials was put
into doubt when, a week before the results
were published, the EU banned atrazine and
simazine beginning in 2005. Weed control in
seventy five percent of the non-GM crops in
the farm-scale evaluations was with
atrazine, so the trials were not a
realistic comparison of the future options
for maize.
A further criticism is that there was no
serious attempt to assess the yield or
quality of the crops grown. This means
there is no way to establish whether the
biodiversity gains seen in the GMHT maize
would ever be acceptable in commercial
practice; it is doubtful that commercial GM
crops will ever be managed like the ones in
the evaluation. The most important time to
control weeds is when the crop is at the
seedling stage. In the non-GM part of the
trials, herbicides were used to do just
that whilst in the GM trials, herbicide
application was deliberately delayed to
allow weeds to develop. rape and GM beet
were commercialized would lead to the
skylark becoming extinct in two decades due
to lack of food. Two common weeds and
important sources of food for wildlife, fat
hen and chickweed, could disappear in half
a century. In contrast, these same weeds
might increase in abundance following a
shift from conventional to GMHT maize
cropping due to the greater weed control
exerted by conventional herbicide regimes
compared to those used with the GMHT crops.
However, the validity of the maize trials
was put into doubt when, a week before the
results were
news
: gm
crop trials damage wildlife
The final results of the UK GM farm-scale
evaluations are a severe blow to the
biotech industry. The results showed that
growing GM winter oilseed rape leads to
fewer important food plants for insects and
birds and an increase in grass weeds which
farmers may have to tackle with more
herbicides, which would further damage
wildlife. Friends of the Earth has also
discovered that biotech giant
Bayer
has told the EU
that it wants to withdraw its application
to grow the GM winter oilseed rape trialed
in the UK’s GM farm-scale evaluations.
There is widespread European opposition to
the oilseed rape; Friends of the Earth
discovered that 23 out of 25 EU countries,
including the UK, objected to the GM crop
being grown because of concerns about the
impact on the environment and human
health
source:
Farm Scale Evaluation Report
:
www.defra.gov.uk/environment/gm/fse/resul
ts/fse-commentary.pdf
more information:
Friends of the Earth England , Wales
and Northern Ireland :
www.foe.co.uk/campaigns/real_food/index.html
