Date: 4/8/17 11:23 am From: Bruce Newhouse <newhouse...> Subject: [obol] Willamette Valley habitats
I thought I'd add a little to Joel's fine narrative on Willamette Valley habitats in regard to blackberries.Â 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).Â 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).Â To add to the confusion, the Flora of North America decided to lump R. armeniacus under R. bifrons.Â What a mess!Â It actually is much more arching-cane, I mean, arcane, than this, but probably is not relevant to bird habitat.Â Most folks don't really care, so Himalayan or Armenian Blackberry remains the name of choice.Â (Still want more?Â See: http://www.ou.edu/cas/botany-micro/ben/ben230.html)
Interestingly, there is another major "player" here that is commonly "under the radar."Â European Blackberry (Rubus vestitus) carpets conifer forest understories, while Himalayan/Armenian blackberry prefers open sun.Â 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.Â 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).Â 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.Â 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.
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
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.