Name:
Picea engelmannii - Abies lasiocarpa - Tsuga mertensiana Moist Forest & Woodland Group
Reference:
NatureServe Biotics 2019
Description:
This is a high-elevation group of the Rocky Mountains and eastern Cascades dominated by <i>Picea engelmannii</i> and <i>Abies lasiocarpa</i>. It extends westward into the northeastern side of Mount Rainier in Washington, and as far east as mountain "islands" of north-central Montana. <i>Picea engelmannii</i> is generally more important in southern forests than those in the Pacific Northwest. Occurrences are typically found in locations with cold-air drainage or ponding, or where snowpacks linger late into the summer, such as north-facing slopes and high-elevation ravines. They can extend down in elevation below the subalpine zone in places where cold-air ponding occurs; northerly and easterly aspects predominate. These forests are found on gentle to very steep mountain slopes, high-elevation ridgetops and upper slopes, plateaulike surfaces, basins, alluvial terraces, well-drained benches, and inactive stream terraces. In the northern Rocky Mountains of northern Idaho and Montana, <i>Tsuga mertensiana</i> occurs as small to large patches within the matrix of this mesic spruce-fir group and only in the most maritime of environments (the coldest and wettest of the more Continental subalpine fir forests). In parts of the northern Cascades, the climate is more maritime than typical for this group, but due to the lower snowfall in these rainshadow areas, summer drought may be more significant than snowpack in limiting tree regeneration in burned areas. <i>Picea engelmannii</i> is rare in these areas. <i>Populus tremuloides</i> is a common codominant tree in many disturbed stands. Moisture-loving understory species are diagnostic of this group and may include shrubs <i>Cornus canadensis, Ledum glandulosum</i> (rare), <i>Menziesia ferruginea, Phyllodoce empetriformis, Rhododendron albiflorum, Rubus parviflorus, Salix</i> spp. and <i>Vaccinium membranaceum</i>. The understory may also be dominated by mesic herbaceous species such as <i>Actaea rubra, Calamagrostis canadensis, Clintonia uniflora, Erigeron eximius, Gymnocarpium dryopteris, Luzula glabrata var. hitchcockii, Maianthemum stellatum, Rubus pedatus, Saxifraga bronchialis, Thalictrum</i> spp., <i>Tiarella</i> spp., and <i>Valeriana sitchensis</i>. Disturbances include occasional blowdown, insect outbreaks (30-50 years), mixed-severity fire, and stand-replacing fire (every 150-500 years). The more summer-dry climatic areas also have occasional high-severity fires.
Accession Code:
urn:lsid:vegbank.org:commConcept:40013-{358D06ED-F606-41D7-826C-3DF66CF06EE4}
Plot-observations of this Community Concept:
0
|
