Name:
Pseudotsuga menziesii / Festuca occidentalis Forest
Reference:
Western Ecology Working Group of...
Description:
This association has only been described from the eastern portions of the Mount Hood National Forest in the Barlow Ranger District. This area is on the east flank of the Cascades near the Washington border. This is a low-elevation, dry forest, found mostly on lower slopes and flats, with slight northern exposures, and an average slope of 21%. Elevations range from 2330-3160 feet, with an average of 2700 feet. The sites average 33 inches of rain a year and are typically found on low-nutrient, ash-laden soils. In good condition, the stands are grass-rich, open forests or closed woodlands dominated by large, widely spaced Pseudotsuga menziesii (38% cover) and Pinus ponderosa (13% cover) trees. Quercus garryana is found at low cover in the overstory in 75% of the plots. Pseudotsuga menziesii, Quercus garryana, Abies grandis, and Pinus ponderosa can all be found in the understory at low cover values. Shrubs are a minor component, with Symphoricarpos spp., Amelanchier alnifolia, Mahonia aquifolium (= Berberis aquifolium), and others present at low cover. Festuca occidentalis is the understory dominant, with an average of 17% cover. Carex geyeri, Poa secunda (= Poa nevadensis), Melica bulbosa, Festuca idahoensis, Bromus vulgaris, and Bromus carinatus are often found. Forbs are variable and minor, with Fragaria vesca, Lithophragma glabrum (= Lithophragma bulbiferum), Claytonia perfoliata (= Montia perfoliata), and Osmorhiza ssp. being notable. These forests were likely dominated by Pinus ponderosa before European settlement and changes in the fire regimes. The presence of Quercus garryana is successional, and with fire suppression these will disappear. If the native fire regime can be reintroduced, the cover of Pinus ponderosa and Festuca idahoensis will likely significantly increase in these stands. This is distinct from similar associations in Washington, which are much more productive, have significant shrub cover, and little Pinus ponderosa and no Abies grandis.
Accession Code:
VB.CC.24284.PSEUDOTSUGAMENZ
Plot-observations of this Community Concept:
0
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