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 <i>Thuja occidentalis</i> or may be a mixture of <i>Thuja</i> with <i>Picea rubens</i>. Less abundant associates include <i>Abies balsamea, Acer rubrum, Fraxinus nigra</i>, and <i>Betula alleghaniensis</i>. Shrubs include <i>Lonicera canadensis, Lonicera oblongifolia, Viburnum nudum var. cassinoides</i>, and <i>Acer spicatum</i>. Particularly characteristic herbs are <i>Mitella nuda, Platanthera obtusata, Orthilia secunda (= Pyrola secunda)</i>, and <i>Dalibarda repens</i>; common associates in the herb layer include <i>Cornus canadensis, Clintonia borealis, Gaultheria hispidula, Coptis trifolia (= Coptis groenlandica), Oxalis montana, Linnaea borealis, Tiarella cordifolia</i>, and <i>Gymnocarpium dryopteris</i>. The bryophyte layer tends to have feathermosses (<i>Hylocomium splendens, Thuidium delicatulum</i>, and others), <i>Rhytidiadelphus triquetrus</i>, and <i>Bazzania trilobata</i> more abundant than <i>Sphagnum</i> spp., which are also present. This association is similar to ~<i>Larix laricina - Thuja occidentalis</i> Swamp Forest (CEGL006007)$$, but that type occurs in basins that have deeper peat soils and generally lacks the more upland herb species found in this type. A similar midwestern association, ~<i>Thuja occidentalis - (Larix laricina)</i> Seepage Forest (CEGL002455)$$, lacks red spruce.
Accession Code:
VB.CC.31092.CEGL006175
Plot-observations of this Community Concept:
0
|
