Landscape-scale distribution and persistence of genetically modified oilseed rape (Brassica napus) in Manitoba, Canada

Knispel, Alexis L.; McLachlan, Stéphane M.

doi:10.1007/s11356-009-0219-0

Cited by 74 publications

(85 citation statements)

References 36 publications

(54 reference statements)

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“…A 10-year survey (1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002), along road verges of a motorway revealed that most quadrats showed transient populations lasting one to four years (Crawley and Brown, 2004). These data and data from other demographic studies indicate a substantial turnover of populations of feral oilseed rape: only a small percentage of populations occurs at the same location over successive years, whereas the majority appears to die out rapidly (Crawley and Brown, 1995, 2004;Charters et al, 1999;Peltzer et al, 2008;Elling et al, 2009;Knispel and McLachlan, 2009;Nishizawa et al, 2009;Squire et al, 2011). However, if habitats are disturbed on a regular basis by anthropogenic activities such as mowing, herbicide applications or soil disturbance, or natural occurrences such as flooding, then feral populations can persist for longer periods (Claessen et al, 2005a;.…”

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confidence: 63%

“…Because feral oilseed rape is more prevalent in areas with a high frequency of oilseed rape cultivation (Squire et al, 2011), along high-traffic roadsides (Crawley andBrown, 1995, 2004;Knispel and McLachlan, 2009), and in the proximity to seed handling, storage and processing facilities (Yoshimura et al, 2006;Peltzer et al, 2008), repeated seed immigration from both agricultural fields and transport (as fresh seed spills) has been considered the main source contributing to population persistence, countering high extinction rates at a local scale.…”

Section: Replenishment With Fresh Seed Spillsmentioning

confidence: 99%

“…At present, however, feral oilseed rape is not usually the specific target of road verge management in Europe, but in some areas most roadside verges are likely to be sprayed with herbicides or mown as part of general control of vegetation by municipal or highway authorities (Charters et al, 1999;Knispel and McLachlan, 2009). A range of studies concluded that targeted control of roadside feral plants can be achieved chemically or mechanically (e.g., mowing) at a local scale Warwick et al, 2004;Simard et al, 2005;Gruber et al, 2008;Lutman et al, 2008), provided that monitoring systems are in place to detect where significant populations of feral oilseed rape exist and that any control measures taken are timely (Yoshimura et al, 2006).…”

Section: Management Recommendations and Feasibilitymentioning

confidence: 99%

“…Comparisons of five demographic studies of feral oilseed rape in different EU locations (Denmark, Germany (2), France and the UK), constituting over 1,500 ha and 16 site-years of observations, showed that feral populations generally occur at relatively low densities, with a mean around one population per square kilometre, rising to 15 per square kilometre in areas with a high frequency of oilseed rape cultivation such as the study site at Selommes, Loir-et-Cher, France (Lecomte et al, 2007;Messéan et al, 2009;Squire et al, 2011). The spatial variation in feral populations in part reflects differences in frequency of oilseed rape cultivation and abundance of in-field oilseed rape volunteers in the landscape (Knispel and McLachlan, 2009). …”

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confidence: 98%

“…While many feral populations observed over multiple years were transient at a local scale (e.g., Crawley and Brown, 1995, 2004;Knispel et al, 2008), this apparent transience is likely counterbalanced at a landscape scale by repeated seed addition and redistribution from various sources. Local declines or extinctions in feral populations are likely to be temporary and asynchronous at large spatial scales (Charters et al, 1999; Crawley and Brown, 2004;Peltzer et al, 2008;Knispel and McLachlan, 2009;Nishizawa et al, 2009). On a larger scale in the landscape, feral oilseed rape can thus be considered long-lived with a proportion of the populations founded by repeated fresh seed spills from both agricultural fields and transport, and the remainder resulting from the continuous recruitment of seed from local feral soil seedbanks.…”

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confidence: 99%

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Feral genetically modified herbicide tolerant oilseed rape from seed import spills: are concerns scientifically justified?

Devos

Hails

Messéan³

et al. 2011

Transgenic Res

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Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.1 | P a g e KEYWORDSGenetically modified oilseed rape, herbicide tolerance, seed spillage, ferality, persistence, invasiveness, coexistence, introgression 2 | P a g e ABSTRACTOne of the concerns surrounding the import (for food and feed uses or processing) of genetically modified herbicide tolerant (GMHT) oilseed rape is that, through seed spillage, the herbicide tolerance (HT) trait will escape into agricultural or semi-natural habitats, causing environmental or economic problems. Based on these concerns, three EU countries have invoked national safeguard clauses to ban the marketing of specific GMHT oilseed rape events on their territory. However, the scientific basis for the environmental and economic concerns posed by feral GMHT oilseed rape resulting from seed import spills is debatable.While oilseed rape has characteristics such as secondary dormancy and small seed size that enable it to persist and be redistributed in the landscape, the presence of ferals is not in itself an environmental or economic problem. Crucially, feral oilseed rape has not become invasive outside cultivated and ruderal habitats, and HT traits are not likely to result in increased invasiveness. Feral GMHT oilseed rape has the potential to introduce HT traits to volunteer weeds in agricultural fields, but would only be amplified if the herbicides to which HT volunteers are tolerant were used routinely in the field. However, this worst-case scenario is most unlikely, as seed import spills are mostly confined to port areas. Economic concerns revolve around the potential for feral GMHT oilseed rape to contribute to GM admixtures in non-GM crops. Since feral plants derived from cultivation (as distinct from import) occur at too low a frequency to affect the coexistence threshold of 0.9% in the EU, it can be concluded that feral GMHT plants resulting from seed import spills will have little relevance as a potential source of pollen or seed for GM admixture. This paper concludes that feral oilseed rape in Europe should not be routinely managed, and certainly not in semi-natural habitats, as the benefits of such action would not outweigh the negative effects of management.3 | P a g e INTRODUCTIONThe global area cropped with genetically modified (GM) crops has consistently increased each year since they were first commercially cultivated in 1996 (1.7 million hectares), reaching 148 million hectares in 2010 (James, 2010). The advent of GM crops and their rapid expansion in terms of cropping area evoked intense debate about their safety (Hails, 2000; Devos et al., 2008b;Waltz, 2009; Gaskell et al., 2011). Concerns have been raised that the commercial release of GM crops could result in adverse environmental and economic effects.Environmental concerns include the potential for altered fitness of the crop ...

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confidence: 63%