[PCA] [MPWG] Electronic Public Discussion: Evaluating the Invasive Potential of Imported Plants

[Steve Erickson]

> >>> Bob Beyfuss <rlb14 at cornell.edu> 12/19/2006 4:40 PM >>>
> New or different plants do not displace established  existing
plants in healthy, undisturbed  ecosystems. 

My observation is that this is not so. I'll provide two quick
examples.

Cytisus scoparius (Scot's Broom) commonly invades and
establishes on intact prairie (grassland) remnants in Western
Washington. 

I'm currently watching Epilobium hirsutum (Hairy Willow
Herb) increase exponentially (forming moncultures) in an
undisturbed high salt marsh on Puget Sound. This species now
covers more than 20 acres. It is not visible at all in aerial
photographs from 1995.

While disturbance may increase the frequency and success of
colonization by new species, it is not always necessary.

-Steve
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Frosty Hollow Ecological Restoration
“Helping Nature Heal”
Box 53
Langley, WA  98260
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