environmental enhancement again

Ian Sheldon isheldon at telusplanet.net
Wed Jan 16 12:13:15 EST 2002

One of the European examples Norbert may be making reference to is the
British Large Blue (Maculinea arion). I was living in England at the time of
the extinction of this beautiful butterfly, and the cause of its demise was
discovered too late. For those who dont know the story of England's possibly
most famous butterfly extinction, its well worth checking out. Changes in
grasscutting practices over several decades led to longer grasses, which
resulted in the demise of the red ant species on which the Large Blue is
dependent to complete its larval phase. Not only is it an excellent example
of the dependence of a species on human-induced disturbance, but an
ecological marvel as well. Perhaps the species had been dependent on
artificial grazing/harvesting for centuries. Lessons learned from this
example may help the continental European species in the genus from further
dwindling. And an example of horrendous damage I agree! Unfortunately I am
not up to date on the proposed reintroduction of a large blue to the old
sites of M. arion.

On a similar note, while studying in England I visited some heathland sites
where sheep grazing was reintroduced to stop the demise of the Pasque flower
(and early spring crocus of sorts). With only a handful of sites left in the
country, conservation biologists fortunately ascertained that the short
grass maintained by a long history of grazing was essential for the Pasque
flower. Fortunately the Pasque flower did not go the way of the lycaenid.

With Europe's high population density and extensive land-use and history of
disturbance, we should certainly pay attention to what has happened there. I
am sure there are countless examples from which we can learn.

Ian Sheldon

----- Original Message -----
From: "Kondla, Norbert FOR:EX" <Norbert.Kondla at gems3.gov.bc.ca>
To: "'lepsl'" <leps-l at lists.yale.edu>; "'altabugs'"
<albertabugs at majordomo.srv.ualberta.ca>
Sent: Tuesday, January 15, 2002 12:42 PM
Subject: BUGS: environmental enhancement again

> Just a couple of observations:
> Ian Sheldon observed: "I am not sure one can inflict "horrendous damage"
> species that rely on disturbance and that are being ousted by natural
> selection. It is natural selection after all."
> Yes succession is natural. Where this is a concern is when it is not
> accompanied by the natural or historically prevalent disturbance regime.
> This is a reality in many parts of the planet. Close to home it is a
> issue because we have been suppressing forest fires for almost 100 years.
> This has resulted in both unnatural tree encroachment into formerly
> unforested habitats and also unnatural tree ingrowth and canopy closure -
> even tho the process itself is quite natural. This of course has profound
> effects on the organisms that cannot live under forest canopies. In parts
> western North America eg. Arizona there are ecological restoration efforts
> underway to deal with this situation. A clear case of horrendous damage
> been well documented in Europe. The issue is the butterflies that depend
> early seral habitats and which then have become endangered because the
> previous 'disturbing'/habitat maintaining practices ceased or the habitat
> became protected. This has created a number of endangered species that
> not have gone that way. In my view, creating endangered species through
> changes in land use practices and allowing natural succession to continue
> unchecked is indeed horrendous damage.
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Norbert Kondla  P.Biol., RPBio.
> Ministry of Sustainable Resource Management
> 845 Columbia Avenue, Castlegar, British Columbia V1N 1H3
> Phone 250-365-8610
> Mailto:Norbert.Kondla at gems3.gov.bc.ca
> http://www.env.gov.bc.ca


   For subscription and related information about LEPS-L visit:


More information about the Leps-l mailing list