RE: Non-native species

From: Philip Thomas (thomasp@maui.com)
Date: Sun Jan 05 1997 - 17:34:09 PST


Date: Sun, 5 Jan 1997 15:34:09 -1000 (HST)
From: Philip Thomas <thomasp@maui.com>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg70$foo@default>
Subject: RE: Non-native species


>Philip Thomas wrote:
>
>>BTW, Hawaii's only NATIVE CP is Drosera anglica (on the island of Kauai,
>>probably brought in as a seed on the foot of a migrating golden plover).
>
>I think I understand the point, but to pick a nit, it seems that Hawaii's
>only NATIVE CP was introduced by a bird. So, in a situation like this (land
>formed by volcanic action), are native species those introduced by
>non-humans, and invaders introduced by humans?

Precisely BY DEFINITION native species are those NOT introduced by humans
("invaders"--a term usually used for particularly "bad" weeds/other
species--are a subset of non-natives, in this context).

>Obviously, for an island
>like Kauai to have any plants (or animals) they would have to have been
>introduced at some time or other. You could make the point (call it
>sophistry if you want, I don't mind) that since humans also arose through
>evolution, (or creation, which would lead to a different line of argument)
>they are part of nature and so their actions should be considered different
>from other creatures only to the extent that they are so capable of
>changing things.

I think that is a very eloquent summary of how I feel about a very sticky
topic. However, Homo sapiens in most of historic time (including all of
"modern history") is certainly this creature with ability to change this
MUCH MORESO than ANY OTHER SPECIES. The difference between native
species and introduced (non-native) species can be expressed in terms of
RATE OF INTRODUCTION/RATE OF CHANGE OF RATE OF INTRODUCTION. The rate of
change of introductions is MANY ORDERS OF MAGNITUDE GREATER than
historically (geologic time); biological evolution simply can't keep up
with the current rate of "introductions". (e.g. there are [to orders of
magnitude] 1,000 native flowering plants in Hawaii, which have
arrived/evolved over a period of over 7,000,000 years, vs. 10,000
introductions in the past 200 years. Many of these plants are from areas
of well-developed, ecologically "full" continental ecosystems [e.g. SE
Asia, S. Africa, S. America] where intense competition has been "selected
for" for millions of years, and they have arrived into an "ecologically
barren" region with MUCH fewer/very different types of pressures. Many
of these (e.g. Pennisetum setaceum on the Big Island) dominate
landscapes/entire ecosystems "INSTANTANEOUSLY" (in geologic time).
With this rate of change with this set of diversity swamping "fragile"
ecosystems (let's NOT discuss that here; it's a long topic in itself),
there's NO CHANCE for "biological evolution" [="natural" forces] to
compete. WE LOSE INCREDIBLE BIODIVERSITY.

Granted, effects on islands are often more dramatic; Hawaii is perhaps
the most dramatic example on the planet (the islands are [well, "were"] more
biologically isolated than any other terrestrial system.

However, the point is that non-native invasions are neither uncommon nor
without dire, long-reaching effects. For a couple more websites with
examples of the problems created by non-native species (there is
increasing concern nationally and internationally about this topic), see
(in addition to http://www2.hawaii.edu/~halesci/AlienSpeciesInHawaii):

http://www.tnc.org/science/src/weeds/tncwwmr.htm
http://www.nfrcg.gov/nas/

Note also the organizations concerned (The Nature Conservancy, USGS/BRD
[formerly the National Biological Service]); this are mainstream,
important folks!

There are numerous other sites & organizations concerned w/ alien
species, these are just to getyou started.

Thanks for the discussion & interest; I encourage you to do what you can
to help curtail these problems. Though this thread is not directly
talking about CP, it IS directly relevant, for much CP habitat is
directly impacted (negatively, I might add) by alien species on an
international scale.

-Philip Thomas
 Research Associate
 Research Corp. of Univ. Hawaii
 Hawaiian Ecosystems at Risk Project

-------------------------------------------------------------------------
        Philip A. Thomas - thomasp@maui.com OR halesci@hawaii.edu
            P.O. Box 1272 - Puunene, Maui, Hawaii 96784 USA
          voice: (808) 572-9306 ext. 3233 fax: (808) 572-1304
            http://www.maui.com/~thomasp/PhilipAnthonyThomas

## Opinions expressed are my own and do not necessarily represent ##
## the views of USGS/BRD, RCUH, CPSU, UH, or anyone besides just me! ##



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