Name:
Abies lasiocarpa - Picea engelmannii / Calamagrostis canadensis Forest
Reference:
Western Ecology Working Group of...
Description:
This spruce-fir riparian forest type is a minor and sporadic plant association in the middle Rocky Mountains of Colorado and Utah, but is consistently present in most mountain ranges in the northern Rocky Mountains well into Canada. It occupies the lower to middle reaches of the subalpine zone, occurring from 1400 to 2776 m (4595-9075 feet), and occasionally to 3300 m (10,800 feet) in elevation. It has the coldest and wettest environment in the <i>Abies lasiocarpa</i> alliance because of high groundwater levels and cold-air drainage from surrounding uplands. Snowpack often persists late into the season. Sites include toeslopes and footslopes and stream terraces of all gradients. However, the most common landscape position is poorly drained depressions or basins, from pond margins, to fairly sizable kettleholes to minor swales. These depositional positions are typified by fine-textured soils. These sites are typically subirrigated and in the early portion of the growing season are saturated to the surface, but they become dry by mid summer or earlier. The canopy of this type is highly variable with some stands having a dense canopy of <i>Abies lasiocarpa</i>, with <i>Picea engelmannii</i> a lesser component and <i>Pinus contorta</i> or <i>Populus tremuloides</i> seral components. <i>Abies</i> and <i>Picea</i> are sometimes only poorly represented as stunted or very slow-growing individuals in old-growth stands of persistent <i>Pinus contorta</i>. These prolonged seral conditions typically occur with sites that are not too wet. Sites are sufficiently wet that <i>Pseudotsuga menziesii</i> and <i>Larix occidentalis</i> do poorly here as seral species. <i>Pinus albicaulis</i> may occur when this type extends into the upper subalpine zone in protected basins, where it is most commonly found on hummocks or drier sites within the stand. Shrub associates include <i>Ledum glandulosum, Lonicera involucrata, Ribes lacustre, Vaccinium caespitosum, Vaccinium myrtillus</i>, and <i>Vaccinium scoparium</i>. <i>Rubus parviflorus, Symphoricarpos albus</i>, and <i>Spiraea betulifolia</i>, can comprise a distinct layer in some stands. The modal undergrowth condition is characterized as a relatively lush sward of <i>Calamagrostis canadensis</i> (or <i>Calamagrostis stricta</i>) with scattered shrubs and herbs. Other graminoids can include <i>Carex aquatilis, Carex disperma, Carex microptera (= Carex festivella), Carex norvegica ssp. inferalpina (= Carex media), Carex utriculata, Luzula parviflora</i>, and <i>Poa reflexa</i>. Associated forbs are geographically variable, and occasionally they can be conspicuous. Those forbs with high constancy include <i>Thalictrum occidentale, Senecio triangularis, Veratrum viride, Heracleum maximum, Dodecatheon jeffreyi, Maianthemum stellatum (= Smilacina stellata), Streptopus amplexifolius</i>, and <i>Equisetum arvense</i>. Moss cover is typically high.
Accession Code:
VB.CC.32200.CEGL000300
Plot-observations of this Community Concept:
0
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