Name:
A.190
Reference:
EcoArt 2002
Description:
This alliance includes subalpine riparian or seep slope conifer forests in the Rocky Mountains and portions of the Pacific Northwest. These forests occur in landscape positions where snowmelt moisture creates shallow water tables, seeps, or streamside flooding during much of the growing season. Sites include moist toeslopes, subirrigated stream terraces, alluvial benches, pond margins, wet meadows, or slopes and hillsides that are wet in spring and early summer. Soils often show evidence of podzolization processes and gleying due to seasonally saturated conditions, and tend to be acidic. They often have high organic matter content throughout the profile, but can vary from shallow to deep, and coarse to fine-textured. The moderately dense to dense tree canopy is characterized by the codominance of the conifers ~Abies lasiocarpa$ and ~Picea engelmannii$, with ~Pinus contorta$ codominant in some stands. Other conifers may also be present in small amounts. The shrub layer is often well-developed occurring as a dense ribbon along streams or where there is a break in the forest canopy. Important shrubs include ~Ledum glandulosum, Vaccinium$ spp., ~Ribes lacustre, Oplopanax horridus, Alnus incana, Salix$ spp., and ~Lonicera$ spp. The herbaceous layer is typically lush and dominated by a mixture of mesophytic forbs and graminoids, including ~Calamagrostis$ spp., ~Carex$ spp., ~Caltha leptosepala, Dodecatheon jeffreyi, Deschampsia caespitosa, Equisetum$ spp., ~Ligusticum$ spp., ~Linnaea borealis, Senecio triangularis$, and~Streptopus amplexifolius$. Diagnostic characteristics of these forests are that the average tree canopy is greater than 60% cover with ~Abies lasiocarpa$ as the predominant conifer in the tree-regeneration layer, and they occur on sites saturated until late summer by snowmelt, occurring below seeps on lower hill slopes or in riparian habitats.
Accession Code:
VB.CC.1600.A190
Plot-observations of this Community Concept:
0
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