Name:
Abies grandis - Pseudotsuga menziesii Mesic Cascadian Forest Alliance
Reference:
NatureServe Biotics 2019
Description:
This alliance consists of forests dominated by <i>Abies grandis</i> or a mix of <i>Pseudotsuga menziesii</i> with <i>Abies grandis</i>. Several other conifers can dominate or codominate, including <i>Pinus contorta, Pinus monticola</i>, and <i>Larix occidentalis</i>. Understory species are characteristic of the eastern Cascades and include <i>Acer circinatum, Achlys triphylla, Anemone deltoidea, Chrysolepis chrysophylla, Cornus nuttallii, Mahonia nervosa</i>, and <i>Vancouveria hexandra</i>. This alliance occurs along the eastern slope of the Cascades south of Lake Chelan, in the eastern Okanogan Highlands in Washington, south to Mount Hood in Oregon. Elevations range from 590 to 760 m in the eastern Cascades. All aspects are represented, and slopes can be flat to steep. Parent materials are highly variable, but volcanic ash is often present in the soil profile.<br /><br />These woodlands generally occur on sites which are intermediate in moisture between forest types dominated by <i>Abies grandis</i> and low-elevation steppe grasslands or woodlands, which occupy wetter and drier sites, respectively. <i>Abies grandis</i> woodland associations occur on a wide variety of soil types but are usually associated with well-drained soils, and often occupy southerly or westerly aspects. The shrub layer is dominated by the prostrate, mat-forming <i>Arctostaphylos nevadensis</i>, with <i>Arctostaphylos uva-ursi</i> also being important in some stands. The other associations have taller shrub layers composed of cold-deciduous or ericaceous species, including <i>Acer circinatum, Acer glabrum, Arctostaphylos nevadensis, Chrysolepis chrysophylla, Cornus nuttallii, Holodiscus discolor, Mahonia nervosa</i>, and <i>Vaccinium membranaceum</i>. The herbaceous component of these woodlands is dominated by perennial bunchgrasses or cespitose sedges. <i>Calamagrostis rubescens</i> is present in almost all stands, and can be dominant (up to 70% cover), and <i>Carex geyeri</i> is another dominant species in some stands. Lichens can be common on some sites, primarily growing on exposed rock.
Accession Code:
urn:lsid:vegbank.org:commConcept:38803-{0EE66609-5733-4D22-B280-D76A1ED5D7FF}
Plot-observations of this Community Concept:
0
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