[obol] Russian Olive/habitat discussion

[Bruce Newhouse]

>
> ------------------------------------------------------------------------
>
> Subject:
> [obol] invasive species
> From:
> Linda Fink <linda at fink.com>
> Date:
> Fri, 02 Mar 2007 06:49:41 -0800
> To:
> obol <obol at lists.oregonstate.edu>
>
> To:
> obol <obol at lists.oregonstate.edu>
>
>
> Hooray, Mike! I couldn't agree more. What are we going to do as the 
> climate gradually changes? Eliminate all the survivors because they're 
> non-native? Ecosystems are not stagnant... Linda Fink, who loves her 
> ivy-covered wall even though she has to climb a ladder several times a 
> year to whack off all the developing flowers (and liberate the nest 
> boots that the chickadees love)
>
> Yes, I know that Russian Olive is non-native and considered a weed 
> species, but the facts are this introduced tree has been here on the 
> dry side for over 100 years and many native bird species now depend on 
> this dense berry producer for winter survival ( WOSNews 103). O well 
> the damage has been done for the most part and now we need to keep 
> tabs on bird species that have depended on invasive species for many 
> generations. Just my opinion.
> Later Mike
>
> ********************************************************************
> Mike & MerryLynn Denny
Well, heck.  I hate to disagree (but only partly!) with Mike, although I 
know he is a wonderful ecologist as well as an ace birder.

Recently there was a thread on OBOL about values vs. damage of 
invasives.  (It went off onto human impact on the environment and then 
tapered off.  Hopefully, my comment here won't lead to that same road.)  
It started with a discussion about Armenian (formerly Himilayan) 
blackberries, and Russian olive is very similar.  There is wide 
agreement that many invasive species have positive values as well as 
negative ones (we assign those values).  Where I diverge from Mike's 
viewpoint (and some others on OBOL) is that I don't think we should 
consider a current, positive value of an invasive species -- and then 
stop.  Rather, I think we also should consider the negatives, both 
present, and potential future.  And as I mentioned in that recent 
thread: invasive species continue to expand (for the most part), so the 
situation is not static.

In the case of Russian olive, I think asking and answering these 
questions would give a more holistic picture:  What native plants have 
been displaced by it?  What native pollinators or other invertebrates 
are gone that were dependent on those plants?  Has it adversely affected 
any vertebrates?  Has it changed local hydrology, and if so, what are 
the spinoff effects of that?  Is it still expanding its range, and if 
so, what are projected impacts of that expansion?

The recently-adopted Oregon Conservation Strategy (viewable/downloadable 
from the ODFW web site at: 
http://www.dfw.state.or.us/conservationstrategy/contents.asp) lists 
Russian Olive as a "documented invasive plant" in the Blue Mountains 
Ecoregion "known to impact native fish and wildlife populations."   This 
list was developed by a committee of  stakeholders including wildlife 
biologists, forestry and agricultural industry representatives, 
botanists, ecologists, etc.  They also developed a list of Strategy 
Species which are declining in the area.  On the bird list of Strategy 
Species for the BM Ecoregion, I don't think I see any species that 
depend on Russian Olive (but someone like Mike who knows the habitats 
and birds better in that area might be able to make that call better 
than I).

Finally, regarding Linda's comment, I agree (as an ecologist) that 
ecosystems are not stagnant, but I disagree if the implication is that 
if we introduce an invasive and it completely changes the makeup of an 
ecosystem (perhaps even causing local extinctions) that it is good 
simply because it is change.  On the other hand, Linda, I highly 
appreciate your efforts in clipping off your ivy flowers, which perhaps 
tells me that you realize that the fruits of the ivy could be carried 
beyond your property, and cause problems on other public or private lands.

If we want to help our declining and rare bird species (as well as other 
animals, plants and fungi), then we need to pay attention to what 
habitats they need, and what the impacts are on those habitats.  
Personally, I don't accept invasive species as a past or static 
problem.  It is a present and future problem that will continue to 
negatively impact rare species.  And there are a lot of great folks out 
there in OBOL-land working hard to minimize those impacts!

Bruce Newhouse in Eugene



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