Antarctic flora & fauna (was: New Zealand plants...)

Robin Leech releech at TELUSPLANET.NET
Wed Jul 28 22:30:37 CDT 2004


Hi Ken,

Well, in the Canadian Arctic, we do have a dwarf willow, Salix arctica,
which is very common, but is rarely found being more than 15 cm (6 in.)
tall.  I do recall a  controversy about it.  I believe that almost all of
the plants are female, but somewhere in the high Arctic, a male plant was
found by a grad student.  This goes back 20 years or more ago.  This find
was regarded with great excitement.

I would not say that Salix arctica is a rare species, or that it is in
danger of becoming extinct.  It is very wide-spread throughout the Canadian
Arctic.

There will be problems comparing the Arctic with the Antarctic, mainly
because most of the Arctic has adjacent land mass, or adjacent islands, so
that there are only small distances between any sort of land and the most
northern tip of Ellesmere Island.  Antarctica, on the other hand, is
completely isolated by great distances of open ocean.

Dwarf forms of both plants and animals are common in many species in the
marginal limits of their habitats, whether it be altitudinal, compass
directional, climate, or some other limiting factor.

Robin Leech

----- Original Message -----
From: "Ken Kinman" <kinman2 at YAHOO.COM>
To: <TAXACOM at LISTSERV.NHM.KU.EDU>
Sent: Wednesday, July 28, 2004 8:39 AM
Subject: Re: Antarctic flora & fauna (was: New Zealand plants...)


> Dear All,
>       First, let me apologize for the poor English ("may have went
extinct") in my post last night.  Ouch!!  It obviously should have read
"perhaps went extinct" or "may have gone extinct".
>
>       Earlier yesterday, I mentioned a warm period ending about 2.2
million years ago.  Reading more this morning, I found that this was an
older estimate done back in the 1990's.  A more recent estimate (2001) dates
this period of high ocean levels from 2.2-2.0 million years ago (based on
the Tuapaktushak Beds of Alaska).  This is getting very close to the
beginning of the Pleistocene.  I do not know of any direct evidence from
Antarctica itself for this period of time, but one can infer possible
pockets of tundra in Antarctica near the end of Pliocene (perhaps including
dwarf Nothofagus?).
>             ----- Cheers,  Ken
> P.S.  I wonder how common it is for dwarf forms to be the last of their
species.  Dwarf mammoths surviving on at least one island.  A dwarf
Nothofagus in Antarctica (or could it be conspecific with an extant Chilean
species?).  I'm curious if there are other such examples.
>




More information about the Taxacom mailing list