Novel crops what are the ecological risks

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Novel crops what are the ecological risks?

• Dr Brian Johnson
• British Statutory Conservation Agencies

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human and animal safety
environment
But how sustainable is agriculture generally?
sustainability
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Agriculture Damages Natural Systems

• Land take destroys natural forests, wetlands and
  grasslands some wildlife adapts (given time)
• Intensification damages biodiversity in farmed
  landscapes
• Overgrazing, irrigation and arable production can
  destroy soils 40 arable soils severely
  degraded in North America
• Water for agriculture pollutes and decreases
  quantities in rivers and aquifers
• Most damage has been done by non-chemical
  agriculture (but is accelerated by agrochemical
  use)
• Damage and land take is continuing
• Limit to available arable soil area

We need food but not more of this type of
agriculture
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Risks from novel crops

• Direct Risks
• Invasiveness
• Toxicity to humans, livestock and wildlife
• Gene flow to other crops, wild relatives
• Gene stacking

• Indirect Risks
• Changes in management practices
• Changes in patterns of land use

Must be viewed in the context of risks from what
we do now
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GM crops
Toxicity?
Harm to soils?
Gene flow via pollen or seed?
Stacking?
Invasiveness?
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Gene Flow and Gene Stacking

• Gene flow to other crops and wild relatives can
  and does occur to and from many crops
• We need to know the rate of gene flow and the
  likely ecological impacts of transgene escape

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Does gene flow matter?

• Will resistance and tolerance genes increase
  fitness of domesticated/wild hybrids? What might
  be the impacts on native species and ecosystems?
• Could GMOs with decreased fitness have adverse
  impacts on wild populations? (e.g. GM fish)
• Will insect resistance genes threaten insects in
  the wild?
• Will gene stacking lead to the use of even more
  herbicides to control weeds?
• Could there be effects on soil processes?

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Indirect risks - changing crop management

• GMHT crops enable broad spectrum herbicides to be
  sprayed over the crop
• Potential to intensify farming still further,
  particularly on marginal land
• Rotations could become shorter/less diverse if
  pest and disease constraints are lifted
• The impacts on of these kinds of changes on
  biodiversity could be positive, negative or
  broadly neutral

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Concerns about GMHT crops

• Intensification of arable weed control may lead
  to fewer resources for wildlife?
• Greater risks from spray drifting on to hedgerows
  and field margins in growing season?
• Gene transfer and gene stacking in crops?

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GMHT crops work!

• Research in 1990s showed that GMHT systems in
  maize, beet and oilseed rape were
• More efficient than conventional herbicide
  regimes
• More reliable from year to year

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Of Weeds Left After Treatment of Winter (W) and
Spring (S) Oilseed Rape With Conventional and
Glufosinate Herbicides
After Read and Ball, Aspects of Applied Biology,
55, 1999
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UK Farm Scale Evaluations
To compare the effects on biodiversity of the
ways in which farmers use herbicides in GM and
conventional winter and spring oil seed rape,
maize and beet (sugar and fodder )
Focussed on the impact on abundance and diversity
of farmland-dependent wildlife
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What the research involved

• Comparisons of biodiversity associated with GMHT
  crops and their non-GM equivalents
• 1 year pilot, 3 years data
• Average 25 farms per crop per year
• Realistic farming situations
• Farming industry find the sites, then not
  involved
• Research consortium monitor crop management

Not designed to assess gene flow/impact or to
add to data on human health and safety
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Results

• Over whole growing season, far fewer weeds (plant
  density and biomass) and non-crop seed return (up
  to 80 less) in GMHT rape and beet
• Reduction greatest in broadleaved weeds
• Conventional (atrazine-treated) maize had very
  low biodiversity. Higher weed populations in
  GMHT maize
• Fewer bees and butterflies in GMHT beet and rape
  than in conventional crops
• More springtails in GMHT crops in late summer
• Not much impact on field margins, but small
  increase in herbicide damage to boundaries around
  GMHT crops

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Do the results show harm to farmland biodiversity?

• Not yet possible to estimate size of impacts in
  beet and rape on whole arable landscapes, only
  the direction of trends
• Results show that the GMHT system in beet and
  rape would reduce in-crop biodiversity if
  released according to the application dossiers
• These crops are important to biodiversity because
  they are break crops in cereals

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Harm in the context of policy

• UK government policy is to increase biodiversity
  in farmland landscapes
• Indicators are farmland bird populations and
  Biodiversity Action Plan plants (e.g. rare arable
  weeds)
• If GMHT rape and beet were grown as in the FSEs
  (I.e. as specified in the application dossiers)
  then in-crop biodiversity would be significantly
  reduced. If GMHT maize were grown then it would
  be increased.
• Trend for biodiversity in GMHT rape and beet is
  in opposite direction to govt policy of
  increasing biodiversity on arable fields. Trend
  for maize is the reverse.

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Thank You!