Hi Wayne,
These are good comments but now you've put us all on the spot: Can you
confess your age? :-)
As for the suspicions raised by your second paragraph (that Richard Eddy
might have picked out examples of relatively "natural" habitats within
the area around OSC), I wouldn't doubt them.
However we're not well served by studies that dismiss earlier accounts
of dominant understory vegetation, just because that vegetation wasn't
quantified in the earlier studies. Understory vegetation is where many
birds live.
Joel
On Sat, 2017-04-08 at 19:59 -0700, Wayne Hoffman wrote:
Hi -
I grew up in western Oregon - lived southeast of Eugene (Pleasant Hill
area) until I was 10 - I remember picking both "Himalayan" and
"Evergreen' blackberries, to eat and for pies in my childhood. I do
not have much recollection of prevalence, but they were not hard to
find in pickable volumes.
One other thought: I wonder if Richard Eddy chose his sites because
they had native vegetation, and chose to avoid sites with alien
berries? That might have been a logical thing to do, depending on his
goals, but if so, we can only conclude that there were enough such
sites still around that he could find some, and enough that the
warblers were persisting. The landscape might have already had a
major presence of the alien terrorists.
Wayne
On 4/8/2017 7:06:19 PM, Joel Geier <joel.geier@xxxxxxxx> wrote:
Hi Bruce (& OBOLites),
Thanks for your informed discussion of Eurasian blackberries and
their impacts on bird habitats in the Willamette Valley.
About Franklin and Dyrness (1989), I'm inclined to think that they
might just have been disinclined to list one of these invasive
species, as I remember Himalaya/Armenian blackberries (along with
scotch broom) were quite evident along the I-5 corridor when I
passed through on a Greyhound bus in May of 1985, and during my
subsequent years of residence in the Puget Sound area.
Anyway I agree that the effects on native bird species must be
profound. Looking at the PEERJ paper that Doug Robinson cited, at
least three of the species that were common in 1952, but not found
in 2013 re-surveys of approximately the same areas, would have been
negatively impacted by invasion of Eurasian blackberries in the
understory. Specifically:
Nashville Warbler (invasion of native understory)
Chipping Sparrow (ditto)
Northern Rough-winged Swallow (overgrowth of river/creek banks
nesting strata by blackberries).
--
Joel Geier
Camp Adair area north of Corvallis
