Date: 4/8/17 11:23 am
From: Bruce Newhouse <newhouse...>
Subject: [obol] Willamette Valley habitats
Greetings, Obolites!

I thought I'd add a little to Joel's fine narrative on Willamette
Valley habitats in regard to blackberries. There's a lot of
botanical Latin names here, so please delete now if you consider that
as a form of torture! : )

The native Rubus vitifolius mentioned by Eddy in 1953 has been known
more recently as Rubus ursinus (common name Pacific Blackberry, aka
Dewberry or Trailing Blackberry). The introduced, common and
widespread "Himalayan Blackberry" (R. discolor) was collected and sent
to some botanists in Europe a few years ago, who corrected West Coast
US botanists by determining it to be Armenian Blackberry (R.
armeniacus; native to Armenia). To add to the confusion, the Flora
of North America decided to lump R. armeniacus under R. bifrons.
What a mess! It actually is much more arching-cane, I mean, arcane,
than this, but probably is not relevant to bird habitat. Most folks
don't really care, so Himalayan or Armenian Blackberry remains the
name of choice. (Still want more? See:
http://www.ou.edu/cas/botany-micro/ben/ben230.html)

Interestingly, there is another major "player" here that is commonly
"under the radar." European Blackberry (Rubus vestitus) carpets
conifer forest understories, while Himalayan/Armenian blackberry
prefers open sun. Besides this habitat difference, there are other
differences: European Blackberry doesn't arch as high, usually has a
slightly fuzzy appearance, has pinker and more glandular flowers, and
may have a slightly different (but overlapping) flowering time. In a
study of conifer forests around Fall Creek Reservoir, it was found as
an understory dominant in 91 of the 298 plots examined (and was
present in more as a non-dominant). Birds which might forage on open
forest floors or in the insects associated with a diverse native
understory could be affected by dense European Blackberry
infestation. It is present and expanding in Spencer Butte Park here
in Eugene, as an example, but it is becoming more common in western
Oregon (including the coast).

Also of interest: Franklin and Dyrness (1989) did not include any
introduced blackberries as community dominants in the Willamette
Valley in the classic Natural Vegetation of Oregon and Washington.

Best,

Bruce Newhouse in Eugene


Msg: #8 in digest
Subject: [obol] Re: "Calaveras" Warblers in the Corvallis area in 1952
From: Joel Geier <joel.geier...> Date: Fri, 07 Apr 2017 13:50:16 -0700

An afterthought here:

One think that really strikes me in the Eddy (1953) thesis: http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/34760/EddyRichardHewesJr1953.pdf
is the absence of any mention of "Himalaya" blackberry (Rubus armenica,
a.k.a. Armenian blackberry) in the understory of any of the six sites
that he surveyed around Corvallis in 1952. For example, here's his
description of the oak woodland area:


The area covers about thirty-five acres and is dominated by garry oak
(Quercus garryana). There are many thickets of poison oak (Rhus
diversiloba) and wild rose (Rosa). At one end of the area are piles of
fire wood covered with poison oak, roses, and grasses.

At some of his other sites he mentions the native trailing
blackberry (Rubus vitifolius), so he seems to have been paying attention.

This got me curious as to when Rubus armenica began to spread in the
Willamette Valley. I found this in an OSU Extension circular:

"HB is a native of Western Europe that was introduced in the
United States as a crop in the late 19th century. 'Burbank's
Frankenstein' (after horticulturist Luther Burbank) is thought
to have become naturalized in the West Coast around 1945."

So Himalaya blackberry was just beginning to spread in the wild when
Richard Eddy did his field work.

Coincidentally or not, he also reported very few Common Yellowthroats --
none at four of the sites, and just 1 per 5 hours of effort at the oak
woodland site.

Happy birding,
Joel

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