Name:
Thuja occidentalis - (Picea rubens) / Tiarella cordifolia Forest
Reference:
Eastern Ecology Working Group of...
Description:
These forests of northern white-cedar mixed with other boreal conifers are found on damp slopes in the cooler regions of the northeastern United States and adjacent Canada. They occur on gently sloping hillsides, or at slope bases, with significant seepage of cold calcium-enriched groundwater. The soils are mostly mineral, usually developed over circumneutral to calcareous bedrock, with little peat accumulation; peat is primarily sedge-derived. The canopy may be somewhat open but more often is closed (usually 65-95%), with a patchy shrub layer beneath. The herb layer is locally extensive and usually relatively species-rich. The bryoid layer is very well-developed, essentially continuous, with mossy hollows and hummocks of moss-covered decaying downed trees. The canopy may be strongly dominated by Thuja occidentalis or may be a mixture of Thuja with Picea rubens. Less abundant associates include Abies balsamea, Acer rubrum, Fraxinus nigra, and Betula alleghaniensis. Shrubs include Lonicera canadensis, Lonicera oblongifolia, Viburnum nudum var. cassinoides, and Acer spicatum. Particularly characteristic herbs are Mitella nuda, Platanthera obtusata, Orthilia secunda (= Pyrola secunda), and Dalibarda repens; common associates in the herb layer include Cornus canadensis, Clintonia borealis, Gaultheria hispidula, Coptis trifolia (= Coptis groenlandica), Oxalis montana, Linnaea borealis, Tiarella cordifolia, and Gymnocarpium dryopteris. The bryophyte layer tends to have feathermosses (Hylocomium splendens, Thuidium delicatulum, and others), Rhytidiadelphus triquetrus, and Bazzania trilobata more abundant than Sphagnum spp., which are also present. This association is similar to Thuja occidentalis / Sphagnum (girgensohnii, warnstorfii) Forest (CEGL006007), but that type occurs in basins that have deeper peat soils and generally lacks the more upland herb species found in this type. A similar midwestern association, Thuja occidentalis - (Larix laricina) Seepage Forest (CEGL002455), lacks red spruce.
Accession Code:
VB.CC.23710.THUJAOCCIDENTAL
Plot-observations of this Community Concept:
0
|
