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strate the advantage of a white list over a banned list.</div><div><br>& On 10/26/2010 8:27 AM, Randy Lauff wrote: > > I am, however, confident that any of the jobs you've attributed to [Purple Loosestrife] > can be done by native plants. And, you have conveniently overlooked > their ability to dominate wetlands. Perhaps a drive to Ottawa, through > Quebec would convince you...I did this this summer. Loosestrife has not > only invaded huge areas, it I fear, has won. * this thread has been fascinating, and I haven't been sure I had anything to add, though there have been thoughts about the question if some plants become invasive just because they've only been introduced a few times, and haven't brought their pests along through multiple introductions, as widely introduced species such as Apples have. This summer we were very impressed by how sparse Purple Loosestrife was in New Brunswick and Nova Scotia, in comparison to southern Ontario and Quebec, where Purple Loosestrife has been "controlled" by the introduction of Galerucella Beetles, and is much less widespread than it was before 2004. You can recognize Loosestrife that's been hammered by Galerucella by the holes in the leaves and the twisted and forked character of the stems. This summer, after an irregular spring, herbivorous Insects in general did poorly in eastern Ontario, and the Loosestrife "got away from" the Beetles. Many places where Loosestrife hadn't flowered for some years were again purple. My conclusion is that these were plants that had previously been suppressed by the Beetles, but not killed, in previous years, so that the extent of Loosestrife hasn't yet come to equilibrium with the presence of Galerucella. I think that in another decade a lot of these wounded plants will have died, and that in a year when herbivorous Insects don't thrive, there won't be such a resurgence of bloom as we saw this summer. fred schueler ------------------------------------------------------------ Frederick W. Schueler & Aleta Karstad Bishops Mills Natural History Centre - http://pinicola.ca/bmnhc.htm now in the field on the Thirty Years Later Expedition - http://fragileinheritance.org/projects/thirty/thirtyintro.htm Daily Paintings - http://karstaddailypaintings.blogspot.com/ RR#2 Bishops Mills, Ontario, Canada K0G 1T0 on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W (613)258-3107 <bckcdb at istar.ca> http://pinicola.ca/ ------------------------------------------------------------ ------------------------------------------------------------
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