Name:
Quercus garryana / Toxicodendron diversilobum / Elymus glaucus Woodland
Reference:
NatureServe Biotics 2019
Description:
This type is found along the foothill margins and hilltops of the Willamette Valley of Oregon and from southwestern Washington, and northern California. Currently, small remnants occur, most along the western and southern edges of the Willamette Valley. There are small examples at the eastern end of the Columbia River Gorge, in Oregon and Washington, and a few small examples at the northern end of the Klamath Mountains Ecoregion (in this region, most of the oak woodlands are mixed <i>Quercus garryana - Quercus kelloggii - Arbutus menziesii - Pinus ponderosa</i> stands). Stands range from open woodlands to closed-canopy forests dominated by <i>Quercus garryana</i>. <i>Pseudotsuga menziesii</i> seedlings and saplings are present in most stands, and in many the conifers are beginning to overtop the oaks. Native low shrubs, primarily <i>Toxicodendron diversilobum</i> provide much of the understory cover in the shady areas, averaging 40% of the cover. Other native shrubs (<i>Symphoricarpos albus, Rubus ursinus</i>) and introduced shrubs (<i>Rosa rubiginosa</i>) can occasionally be found. <i>Elymus glaucus</i> grows through the shrubs and in partial shade throughout the habitat in the more open areas, along with other native (<i>Festuca idahoensis ssp. roemeri, Festuca californica, Danthonia californica</i>) and introduced (<i>Holcus lanatus, Poa pratensis, Dactylis glomerata</i>) grasses. Grasses characterize good condition stands, although non-native grasses are predominant at most sites. Native forbs (<i>Galium</i> spp., <i>Osmorhiza berteroi</i>) are a minor component in this type.<br /><br />This is a seral, fire-dependent association throughout most of its range, occupying areas in the Willamette Valley which were protected from the annual native aboriginal burning. There was little mention of <i>Toxicodendron diversilobum</i> in any of the original General Land Surveyor's notes, indicating changes in canopy and understory composition since 1850. These oak woodlands became quite widespread over the last 100 years, but are now rapidly declining due to secondary succession, clearing/logging, development and other threats. Because these are drier, foothill communities, secondary succession is occurring slower here, and restoration is still possible in many areas.
Accession Code:
urn:lsid:vegbank.org:commConcept:29841-{4B5B9F2B-422E-4E13-911D-84D82C8D3F56}
Plot-observations of this Community Concept:
0
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