Subject: Re-introduction of rare species

From: Kenelm Philip <[email-masked]>
Date: Mon, 1 Jul 1996 21:34:53 -0800

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

                                                Ken Philip
[email-masked]

P.S. Just got back from 2.5 weeks on the Dempster Highway, Yukon Territory.
Lots of _Nympalis antiopa_ (Mourning Cloak) and one female _N. vau-album_
(Compton Tortoise Shell) at kilometer 412.5, in the Richardson Mountains
(tundra habitat). The northward movement of butterflies in this group that
is being observed in Europe may be occurring here as well?