Subject: Re: Butterfleis & Nature Conservation

From: Ron Royer <[email-masked]>
Date: Thu, 9 Mar 1995 15:42:24 -0600

In article <[email-masked]>,
[email-masked] (Hans-Ulrich Thomas) says:

How do butterflies cope with the fact that their habitat, small wetland
areas of about 200-300 m in diameter, is surrounded (now!) by dense pine
tree forest? The distance between two habitats is about 300-500 m. We fear
that the surrounding forest has an isolating effect therefore leading to a
reduction of species diversity.

Does anybody know of European butterfly species (Rhopalocera, Diurna)
typical for wetlands, being cabable of maintaining a viable population
under the described conditions?

How do individuals spread? Do they fly over the treetops or through the
forest of 200-300m?

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I watched  a healthy population of the extremely "local" copper Epidemia
epixanthe disappear from a small bog in northern Wisconsin over the span of
about 30 years as spruce forest steadily encroached and ultimately came to
permanently invade the bog. Although it is not European, and I do not know
the character of the wetlands Hans-Ulrich Thomas is referring to, the
general situation seems similar. My experience tells me that there is
reason to be concerned, especially in relation to highly invagile spp. such
as E. epixanthe.

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Ronald A. Royer <[email-masked]>
Division of Science, Minot State University, Minot ND 58707
701-857-3209 (Personal Office) or 701-857-3161 (Division Office)
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