Subject: Re: Re-intro of rare species & management

From: Floyd Catchpole <[email-masked]>
Date: Tue, 2 Jul 1996 10:34:53 -0400

Hi all;

>      John Shuey's posting on this topic asks "Could it really be this
>easy to start up similar populations?

Ron Panzer successfully reintroduced (Chicagoans correct me if I misremember
this) Polites origenes (Crossline Skipper) into Nachusa Grasslands.  This is
a 1,000 acre site west of Chicago, Illinois, USA, which contains old fields,
woods and moderately grazed prairie (now ungrazed).  An intensive effort is
underway to restore the site to presettlement condition.  Ron introduced
hundreds of P. origenes each year for 3 (?) years before the colony became
successfully established.  Overall habitat is pretty good for this species at
this site.  P. origenes is thriving as far as I know.

snip

Ken Phillips brings up another issue which I would like to address...
" On that topic, I suggest reading
>chapter 9: Stability and chaos in ecology, in the book 'The Sixth Extinc-
>tion', by Leakey and Lewin (Doubleday, 1995). A number of counter-intuitive
>ideas are discussed, backed up by both computer modelling and real-world
>experiments. These include the following: the observed 'patchiness' in the
>micro-distributions of species may represent chaos (in the mathematical
>sense) rather than fine-scale variations within the habitat making micro-
>regions more and less 'fit' for a given organism; mature ecosystems are
>more resistant to invasion by additional species than immature ecosystems
>with the same diversity; assembling an ecosystem from the same pool of
>species in random order will produce a _different_ ecosystem containing a
>different sub-set of species each time it's done (i.e., the 'balance
>of nature' is a myth); creating a working ecosystem by adding the exact
>species that comprise a working ecosystem does not work (referred to as
>the 'Humpty Dumpty effect'). These ideas have rather severe implications
>for traditional ecosystem management!

Very thought provoking ideas, however, much research is done in highly
disturbed ecosystems (often under the assumption that they are stable, eg
(Cole, 1995) (citations below).  Cole showed that some of our (USA) presumed
most stable ecosystems show > 10 fold increase in rate of change in post
settlement times, as compared to pre (white) settlement.  This is measured by
pollen diagrams.

While it is intuitively logical that ecosystems will assemble differently
under differing conditions, and when different species are put into the mix,
yet my observations in nature have yielded a somewhat tempered perspective on
this.   It seems that those ecosystems assembled over thel last 10,000 years
in glaciated (or near glaciated) midwestern North America are surprisingly
similar.  When I find a sand prairie which has been cut for hay, but not
heavily cattle grazed in Kansas, I can picture myself in Illinois.  When I
find a high quality (very species diverse, containing "conservative" species)
woods in western Missouri, I could easily mistake it for a high quality site
in southcentral Illinois (Bennett Springs:Shoal Creek Barrens).  What is
surprising about richly diverse and lightly disturbed ecosystems is their
similarity to each other.

As the botanist C.W. Short said in 1845 "This...(barrens of Illinois) bears a
close relationship, both in appearence and productions, to those districts in
Kentucky...tracts of country which seem to be in a state of transition from
more open prairies to densely timbered forest".

However, the question of recreating a prairie/savanna/ marsh etc., in the
year 2000 AD, and expecting it to come out the same as an ecosystem which has
been functioning for thousands of years, (without plowing, etc.) and which
formed under differing levels of solar insolation and climatic conditions is
another matter.  Here, the points raised on stochasticity seem all too likely
to weigh in.

Cole, Kenneth. 1995. Vegetation change in National Parks, p. 224-227. In
LaRow, E.T., et al. (eds.), Our living resources 1994: A report to the Nation
on the Distribution, Abundance, and Health of U.S. plants, animals and
ecosystems, National Biological Service, Washington, D.C.

Short, C.W. 1845. Observations on the botany of Illinois, more especially in
reference to the autumnal flora of prairies. The Western Journal of Medicine
and Surgery. March: 185-198.

Floyd Catchpole      Kansas State University, Biology Dep't., Ackert Hall,
Manhattan, KS 66506  USA     phone (913) 587-4630 e-mail: [email-masked]

"About 90% of our native flora is restricted to the stable habitats provided
by our original plant communities, so an understanding and stewardship of
such areas is critical if we are to carry forward into the future a
possibility of association with living things other than ourselves, a few
weeds, and cultivars." - Floyd Swink & Gerould Wilhelm.  Plants of the
Chicago Region, 4'th edition, pp 42. Indiana Academy of Science, 1994.