Wednesday 16 April 2014

Pitcher-plant: preserve or eradicate?

Pitcherplant established on Wedholme Flow, Cumbria
 Image: Kevin Walker
A final sneak preview of a paper in the new issue of New Journal of Botany, which - if you are a BSBI member - you can head over to the members' section and start reading right now, or you can wait for the print copy to plop through your letterbox, probably early next week. Many thanks to our publishers Maney for getting this issue on-line in time for some Easter browsing!

In NJB 4.1, you can read a paper by Kevin Walker, BSBI's Head of Science, on Pitcherplant Sarracenia purpurea subsp. purpurea. These showy, North American carnivorous plants have been deliberately planted on lowland bogs and mires throughout Britain and Ireland since the late nineteenth century. 

Pitcherplant established on Lower Hyde Bog, Dorset
Image: David Bird
Kevin says "Since then, established populations have been reported from 38 sites where Pitcherplant has often been conserved for ‘scientific’ reasons. Although there are now several large, long-established colonies, any impacts on native species have been localised due to limited waterborne dispersal of seed. 

"Where plants occur at high density, these impacts have included the displacement of Sphagnum and associated flora, most notably epiphytic liverworts. Many small populations have been successfully removed by hand but, on larger sites, significant regeneration has occurred from juveniles and the seed-bank. The relative effectiveness of other control measures (e.g. chemical treatment, turf-stripping) is currently under investigation". 

Pitcherplant clearance;
Wedholme Flow, Cumbria, 2006
Image: Colin Auld
Kevin's paper concludes that "Pitcherplant is unlikely to pose a significant threat to native species if control is carried out soon after introduction and regeneration is carefully monitored, but the removal of large, established populations will be much more challenging. The control measures required (e.g. chemical treatment, turf-stripping) are unlikely to be acceptable on sensitive sites which support assemblages of rare and threatened plants and insects".

Although Kevin, as Head of Science, is at the helm on BSBI research projects, often in collaboration with partner organisations, and is also responsible for liaising with external/statutory bodies, don't assume that he spends all his time behind a desk! 

Kevin has carried out field-based research on a number of species across Britain and Ireland during his seven years in post so far, and observes "I couldn’t have done any of this work without the records that BSBI recorders provide as well as their intimate knowledge of these species ‘on the ground’. Pitcherplant is a good example of where we’ve been able to call upon this expert knowledge base to build up a clear picture of what impact the species is having at a national scale." 

Kevin will also be heavily involved in the forthcoming Atlas 2020 project: find out more about this here and enjoy his paper on Pitcherplant in the April issue of New Journal of Botany.

1 comment:

  1. I arrived at this article because it seems that this Wedholme problem site would be an excellent source of plants for hobbyists. Charge a contractor a fee to pay for oversight to ensure that damage done to the sensitive habitat is minimised, and allow them to sell these invasive exotics for a clearance price! Further, a portion of proceeds could go to a fund to help support beautiful wetland bogs and other protected locations.


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