Calcareous sedge - moss fen  (S2)

---

Calcareous sedge - moss fens are sedge-dominated communities restricted to northern New Hampshire. They occur either in sloping settings where calcium-rich groundwater seepage is prominent or, less often, in nearly level settings. There is a high diversity of forbs, shrubs, and bryophytes limited to rich fens. These include inland, yellow, and porcupine sedges, numerous orchids and other forbs, and a wide variety of “brown” mosses (those in the Amblystegiaceae family). Half of the rare peatland plants in New Hampshire occur only in this community or in circumneutral - calcareous flarks, another rich fen community. Peat mosses are sparse, but when present they consist of one of a handful of species that are adapted or restricted to calcium-rich and circumneutral conditions (pH in low 7s).

This community contains a suite of species very different from most other peatland types.

Shrubs and saplings include: northern white cedar (Thuja occidentalis) and willows (Salix. spp.).

Herbs include: inland sedge (Carex interior), yellow sedge (Carex flava), porcupine sedge (Carex hystericina), chestnut sedge (Carex castanea), golden-fruited sedge (Carex aurea), slender spike-rush (Eleocharis tenuis), few-flowered spike-rush (Eleocharis quinqueflora), tawny cotton-grass (Eriophorum virginicum), northern cotton club rush (Trichophorum alpinum), red bulrush (Scirpus microcarpus), round-leaved sundew (Drosera rotundifolia), purple avens (Geum rivale), Robbins’ ragwort (Packera schweinitziana), water horsetail (Equisetum fluviatile), variegated horsetail (Equisetum variegatum), marsh horsetail (Equisetum palustre), Kalm's lobelia (Lobelia kalmii), sweet coltsfoot (Petasites frigidus var. palmatus), northern green orchid (Platanthera huronensis), tall white bog orchid (Platanthera dilatata), hooded ladies' tresses (Spiranthes romanzoffiana), and showy lady's slipper (Cypripedium reginae).

Mosses include: Sphagnum warnstorfii, Aulacomnium palustre, Tomenthypnum nitens, Mnium spp., Bryum pseudotriquetrum, Campylium stellatum, Climaceum dendroides, Fissidens adianthoides, and a variety of brown mosses in the Amblystegiaceae family.

Variants: Four variants are recognized.

1.   Typic variant: This variant occurs on shallow peat (less than 0.5 m) and occurs in slightly sloping headwater positions of drainages and former pastures.

2.   Deep peat variant: This variant has deeper peats (0.5-1+ m) and is often found in more level positions or natural basins and drainage margins where basin morphology and hydrology has led to significant peat accumulations. It often occurs as temporary to semi-permanent natural openings in northern white cedar swamps.

3.   Horsetail variant: This variant occurs on seepy, steep river terraces or headwater drainage positions with shallow peat and a strong prominence of horsetails (Equisetum spp.).

4.   Beaver meadow variant: This variant occurs in drainage marshes behind old beaver impoundments in regions with calcareous substrates. Few examples are known, but these wetlands clearly have a different long- and short-term disturbance regime. Orchids appear to be sparse, and certain graminoids may be more prominent than in the above variants, including bottle-shaped sedge (Carex utriculata), Bebb’s sedge, bluejoint (Calamagrostis canadensis), and the rare few-flowered spikerush, but calciphiles are also present, distinguishing this variant from typical beaver meadows. Presumably, this variant is a temporary phase in a natural successional cycle, either toward woody plants (with drainage or sedimentation of the meadow) or toward aquatic vegetation (when flooded).


Good examples of this community occur on private property in Coos County.

Calcareous sedge - moss fens may occur as the primary community of rich sloping fen systems.

a calcareous sedge - moss fen in the town of Columbia (photo by Dan Sperduto)

back to Natural Communities of NH Photo Guide