Subject: Re: Demise of natural Cattails?
From: kbonnici@trentu.ca (Kellie_Bonnici)
Organization: Trent University, Peterborough
Date: Tue, 2 Sep 1997 03:22:01 GMT
Message-ID: <MOD$970901.15062@rec.gardens.ecosystems>
References: <MOD$970830.8016@rec.gardens.ecosystems> <MOD$970831.15104@rec.gardens.ecosystems> <MOD$970901.5713@rec.gardens.ecosystems>
In article <MOD$970901.5713@rec.gardens.ecosystems>, wtmorgan@pilot.msu.edu (Bill Morgan) writes:
>
>In article <MOD$970831.15104@rec.gardens.ecosystems>, William D Hulet
> wrote:
>
>> On Sat, 30 Aug 1997 OperaGoer@webtv.net wrote:
>>
>> >
>> > There has been recent press concerning the weed from a
>> > european-introduction that prefers the low ditches and watery areas but,
>> > while it has lavender blossoms and is attractive, it is very rapidly
>> > replacing our natural cattails.
>> > what possible consequence may this have on our delicate eco-system? What
>> > birds, insects, animals, etc., depend upon these for part/all of their
>> > existence?
>>
>> If you mean purple loosestrife, it is a scary thing to watch. It
>> had/has totally over-run a lot of wetlands here in Southern Ontario. [snip]
>
>You got that right. Very frightening, aggressive. Only the giant grass
>Phragmites comes close as a wetlands invader. Here in mid Michigan, it is a
>major problem.
>
>And yes, in destroying not just cattails, but much wetlands vegetation, it
>does remove resources utilized by birds, small mammals, insects, etc.
>
>>
>> The local university's bio-control labratory has a program where
>> local enviro-types can pick up some European beetles that eat the stuff in
>> exchange for doing some simple records keeping. [snip]
>
>Here at Michigan State U, I know a few people who are working with a
>similar project, now in the phase of doing test releases of beetles to
>control loosestrife.
>
>Amazingly, there are people who object to this because "it's such a pretty
>flower." And it's not like it will ever be eliminated, either. If it is
>knocked back 90-95%, the people working on control will declare victory and
>go home. So the "pretty flower" will be here for a long time to come.
>Still, complaints come in. I guess one must consider the source.
>
>> But there's a bit of controversy about
>> whether we should be bringing another exotic to deal with the first one.
SORRY to quote this whole thing...I have an archaic text editor...
>There's always a risk when this is done. Unfortunately, there are some real
>good examples of introduced biocontrol gone awry. Much of this happened
>decades ago, and was the result of people not testing the "control"
>organism, or in some cases of not even researching the basic biology. So
>you get an introduced snake on some island and it is eating bird's eggs.
>The birds have never dealt with snakes and have no behavioral defenses.
>They're going down the tubes fast. You intoduce the mongoose, which eats
>snakes.
>
>But also eats bird's eggs...
Is this a true story? If so, sould you please tell me more about it?
Thanks,
Kellie
>More recently, a weevil introduced to control musk thistle has been
>devestating the rare Platte thistle and some other native thistles.
>
>At a certain point, biocontrol is like surgery to remove a cancer or
>gangrene. It sure ain't good to lop off body parts, but it may be better
>than letting the whole body die. (i.e, it is an imperfect solution).
>
>>
>> I suspect that part of the anxiety about loosestrife is its
>> extreme visibility. If it didn't convert wetlands into bright pink
>> blotches, it might not have people so pumped up. (One of the scientists
>> involved told me that he's seen another exotic---"yellow canal grass"---
>> filling in some of the void left by the loose strife. As he said "one
>> problem at a time".)
>
>And things will never be like they used to be. In time, many of these
>introduced pests may acquire their own natural enemies whether or not we
>import them. They will be big targets because they are so abundant and
>well, evolution marches merrily along. The question is what damage is done
>while we are waiting for natural processes to take care of the aliens, and
>how long we can afford to wait while doing nothing.
>
>BTW: not just aggressive plants pick up new natural enemies. Five hundred
>years ago, the apple maggot did not exist. But as apples became a common
>crop in North America, hawthorn maggots found it an acceptable alternative
>to hawthorn (aka thornapple). Eventually, the species split and now the
>apple maggot is a separate full-fledged species, and a native pest of an
>alien crop. A third fly, whose maggots feed on domestic (Old World)
>cherries is also coming out of this mix.
>
>So yes, there are problems with biocontrol, and new alien invaders keep
>cropping up all the time. Unfortunately, we can't just turn our backs,
>pretend it's not happening, and just do nothing.
>
>Regards,
>Bill
>
>--
>Bill Morgan
>wtmorgan@pilot.msu.edu
>Center for Room Temperature Confusion
>
>---------------------------------------------------------
>
>The rec.gardens.ecosystems FAQ can be found at the group's homepage
>http://sunsite.unc.edu/InterGarden/rge.html
>
>submissions can be mailed to: ecosys-submit@sunsite.unc.edu
>the moderators can be contacted at: ecosys-admin@sunsite.unc.edu
>