The Natural Communities of Virginia
Classification of Ecological Community Groups
SECOND APPROXIMATION (Version 2.2)
Northern White-Cedar Slope Forests
Northern white-cedar (
Thuja occidentalis) is a dominant or co-dominant tree in these mixed, largely coniferous forests. This is a rare natural community group known from Canada, the Great Lakes region, northern New England, New York, and discontinuously from Maryland, West Virginia, Virginia, Kentucky, and Tennessee. In Virginia, stands occur in small, isolated patches in the Ridge and Valley province. Habitats are on steep, rocky, mesic to submesic slopes that are undercut by streams and have west to north aspects. Underlying bedrock is usually limestone or dolomite, but one Virginia site is underlain by calcareous Silurian sandstone. Eastern white pine (
Pinus strobus) and/or eastern hemlock (
Tsuga canadensis) are the most frequent (often co-dominant) tree associates, with scattered hardwoods also present. Understory and herbaceous layers are variable but generally contain a number of typical calciphiles such as ebony sedge (
Carex eburnea), American barberry (
Berberis canadensis), leatherwood (
Dirca palustris), northern bedstraw (
Galium boreale), and sharp-lobed hepatica (
Hepatica acutiloba).
References: Fleming (1999), Fleming and Coulling (2001).
Click on the images below to open a larger image in a separate window.
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Forest of eastern white-cedar (Thuja occidentalis) and eastern hemlock
(Tsuga canadensis) on a steep, limestone slope above the Maury River in Rockbridge County.
Photo Tom Rawinski |
REPRESENTATIVE COMMUNITY TYPES:
The single classified type is supported by only three plot samples, but appears consistent
with descriptions of similar vegetation in adjacent Tennessee. Although stands of this group are extremely rare in Virginia,
several known examples have not yet been plot-sampled. Click on any highlighted CEGL code below to view the global USNVC description provided by
NatureServe Explorer.
- Thuja occidentalis – Pinus strobus – Tsuga canadensis / Carex eburnea Forest
Southern Appalachian Northern White-Cedar Slope Forest
USNVC:
= CEGL008426
Global/State Ranks:
G1G2/S1
