Name:
Abies lasiocarpa / Calamagrostis canadensis Forest
Reference:
Western Ecology Working Group of...
Description:
This 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 at elevations as low as 1400 m, up to 2776 m, and occasionally as high as 3050 m. It has the coldest and wettest environment in the Abies lasiocarpa alliance because of high groundwater levels and cold-air drainage from surrounding uplands. 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. Areas of bare soil or rock are negligible on most sites and average litter depths are extremely variable. The canopy of this type is highly variable with some stands having a dense canopy of Abies lasiocarpa, with Picea engelmannii a lesser component and Pinus contorta or Populus tremuloides seral components. Abies and Picea are sometimes only poorly represented as stunted or very slow-growing individuals in old-growth stands of persistent Pinus contorta. These prolonged seral conditions typically occur with sites that are not too wet. Sites are sufficiently wet that Pseudotsuga menziesii and Larix occidentalis do poorly here as seral species. Pinus albicaulis 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 Ledum glandulosum, Lonicera involucrata, Ribes lacustre, Vaccinium caespitosum, Vaccinium myrtillus, and Vaccinium scoparium. Rubus parviflorus, Symphoricarpos albus, and Spiraea betulifolia, can comprise a distinct layer in some stands. The modal undergrowth condition is characterized as a relatively lush sward of Calamagrostis canadensis (or Calamagrostis stricta) with scattered shrubs and herbs. Other graminoids can include Carex aquatilis, Carex disperma, Carex microptera (= Carex festivella), Carex norvegica ssp. inferalpina (= Carex media), Luzula parviflora, and Poa reflexa. Associated forbs are geographically variable, and occasionally they can be conspicuous. Those forbs with high constancy include Thalictrum occidentale, Senecio triangularis, Veratrum viride, Heracleum maximum, Dodecatheon jeffreyi, Maianthemum stellatum (= Smilacina stellata), Streptopus amplexifolius, and Equisetum arvense.
Accession Code:
VB.CC.20428.ABIESLASIOCARPA
Plot-observations of this Community Concept:
0
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