Date: Fri, 4 Aug 2000 08:52:10 -0700 (PDT) From: Barry Meyers-Rice <bamrice@ucdavis.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg2357$foo@default> Subject: U. inflata as weed
> Any idea on which view is correct?
>> This is an interesting page that profiles Utricularia inflata in
>> Washington, where the Washington Department of Ecology considers it a
>> non-native, invasive weed.
>
>> This is particularly interesting, perhaps, because some declare that
>> U. inflata is a native plant in Washington.
Hey Dave,
Interesting question, and your sentence sums the situation up perfectly
with the word "view".
If you take the view that it is a native plant, you have to explain how it
is that propagules got all the way from the gulf coast up to Washington
state. The often-invoked bird vector is not likely because this east-west
migration pattern is not something that birds do in North America. One
COULD argue that a vagrant bird in confused migration travelled from the
gulf coast to Washington, AND happened to carry U. inflata propagules, AND
these propagules survived the several day trip intact, AND the propagules
did not wash off on the many wetland stops that our proposed waterfowl
must have made. But then you'd have to explain why it is that U. inflata
(which would seem to be a master of bird-travel) is not scattered
throughout nearly every wetland on the eastern side of the state. Even if
plants couldn't survive a winter, surely each spring the vast numbers of
northward-bound migrating birds would be dragging U. inflata all the way
up to the Great Lakes area. But they aren't.
On the other hand, your view might be that the creature carrying U.
inflata to Washington state is human. I would imagine four most likely
agents.
1)Boaters---U. inflata propagules could hide in any of a number of wet
nooks in boats or boat trailers.
2)Carnivorous plant hobbyists---"Hey, U. macrorhiza grows in Washington,
maybe U. inflata would too....
3)Aquarium trade---a large fraction of nonnative fish introductions in
the
US are due to people in the aquarium trade. Maybe they move plants
around as they dump out their tanks, too.
4)Mosquito abatement---people have tried all sorts of ways to get rid of
mosquitos. I'm sure I read, a long time ago, an article about
someone, somewhere, trying to use Utricularia as mosquito abatement
(by having them eat the larvae). It didn't work. Anyone have this
reference? I'd dearly love to get it.
You can see where I'm leaning---it looks like human intervention is the
probable cause of U. inflata in Washington. In my VIEW, I point out.
Mind you, however it got to Washington, it is not likely to leave soon.
The heavy recreational traffic in Washington (boats) means that even if it
is extirpated from one set of lakes, it will probably show up in another.
And there is a siting of U. inflata in California, too. While this
California population might truly be due to migratory birds (travelling
from the Washington population, that is), it might also be a case of
intentional introduction. (Boats do not visit this lake, which is in a
zoo.)
Barry
------------------------
Dr. Barry A. Meyers-Rice
Carnivorous Plant Newsletter
Conservation Coeditor
barry@carnivorousplants.org
http://www.carnivorousplants.org
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