The Natural Communities of Virginia
Classification of Ecological Community Groups
SECOND APPROXIMATION (Version 2.2)
Calcareous Spring Marshes and Muck Fens
This group contains herbaceous wetlands of calcareous, groundwater-saturated sloughs, abandoned meanders, depressions, and spring overflows on large stream or river floodplain terraces. Restricted to a few sites in carbonate rock districts of the Ridge and Valley region, these very rare habitats are highly threatened by impoundments and hydrological alterations, grazing, and agricultural pollution. Deep, hydric muck soils have high calcium levels and are more or less permanently saturated or flooded by perched groundwater or seepage inputs. Vegetation is marsh-like and characterized by coarse emergent species: arrow-arum (
Peltandra virginica), bur-reeds (
Sparganium eurycarpum and
Sparganium americanum), water smartweed (
Polygonum amphibium var. emersum), lake-bank sedge (
Carex lacustris), hop sedge (
Carex lupulina), Emory's sedge (
Carex emoryi), hairy-fruit sedge (
Carex trichocarpa), Virginia cutgrass (
Leersia virginica), smooth bur-marigold (
Bidens laevis), sweetflag (
Acorus calamus), marsh-marigold (
Caltha palustris), skunk-cabbage (
Symplocarpus foetidus), spotted jewelweed (
Impatiens capensis), blueflag iris (
Iris versicolor), and broad-leaved cattail (
Typha latifolia). Buckbean (
Menyanthes trifoliata) and water horsetail (
Equisetum fluviatile), both very rare species in Virginia, are components at two sites each. A most unusual site in Clarke County consists of a 2 ha (5 ac) marsh developed in the overflow of powerful artesian springs. The marsh here is dominated by broad-leaved cattail and the state-rare, northern disjunct beaked sedge (
Carex utriculata), while deep channels support the similarly disjunct flatstem pondweed (
Potamogeton zosteriformis). Although two occurrences of this community group are located on natural area preserves, several others remain unprotected and vulnerable.
References: Hunsucker and Mueller (1998).
Click on the images below to open a larger image in a separate window.
 |
Calcareous marsh at the foot of a limestone hillside along Folly Mills Creek in
Augusta County (Folly Mills Creek Fen Natural Area Preserve). Marsh vegetation dominated by broad-leaved cattail
(Typha latifolia) and skunk-cabbage (Symplocarpus foetidus) gives way to sedge-dominated wet prairie
on the right. See reference cited above.Photo: Gary P. Fleming
|
 |
Calcareous marsh dominated by broad-leaved cattail (Typha latifolia) and beaked sedge (Carex utriculata), a rare northern disjunct in Virginia. The habitat is a massive spring complex along a tributary of Long Marsh Run in the Ridge and Valley region of Clarke County.
Photo: Gary P. Fleming.
|
REPRESENTATIVE COMMUNITY TYPES:
Three community types belonging to this group have been classified based on quantitative analysis. The first two are each known from two sites in Augusta County and are supported by four and three plots, respectively. The last type is known from a single site and must be considered provisional pending documentation of its replication elsewhere. It is unlikely that additional examples of these very rare communities will be found in Virginia.
Click on any highlighted CEGL code below to view the global USNVC description provided by
NatureServe Explorer.
- Peltandra virginica – Polygonum amphibium var. emersum – Carex emoryi – Impatiens capensis Herbaceous Vegetation
Ridge and Valley Calcareous Spring Marsh (Arrow-Arum – Water Smartweed Type)
USNVC:
= CEGL006244
Global/State Ranks:
G1/S1
Endemic
- Typha latifolia – Caltha palustris Herbaceous Vegetation
Ridge and Valley Calcareous Spring Marsh (Broad-Leaved Cattail – Marsh Marigold Type)
USNVC:= CEGL006245
Global/State Ranks: G1/S1
- Carex utriculata – Sparganium americanum Herbaceous Vegetation (PROVISIONAL)
Ridge and Valley Calcareous Spring Marsh (Beaked Sedge – American Bur-Reed Type)
USNVC:
no equivalent
Global/State Ranks:
GNR/S1
Endemic
