Natural Communities of NH -- Photo Guide

Northern white cedar circumneutral string  (S1)

Northern white cedar circumneutral strings
are a rare community type in New Hampshire found only in the northern part of the state, though it is more common in larger peatlands of both Maine and Canada to the north. The patterned fen systems they are a part of consist of these low peat ridge strings and adjacent, saturated flark hollows, with the flarks often consisting of the circumneutral - calcareous flark community. Slow groundwater movement through the gently sloping wetland causes the patterned or “ribbed” fen micro-topography.

The strings average 0.30 m in height and vary from a few meters to more than 10 m wide. The pH ranges from 6.3–6.7. Peat extends to more than 4.8 m in depth and is poorly to moderately decomposed in the upper meter.

Characteristic Vegetation: Vegetation in this community consists of stunted northern white cedar (Thuja occidentalis) trees amongst a shrub layer of leatherleaf (Chamaedaphne calyculata), Labrador tea (Ledum groenlandicum), bog rosemary (Andromeda polifolia), and bog willow (Salix pedicilaris), and a host of herbaceous plants and mosses.

The strings are dominated by stunted (and heavily browsed) northern white cedar, averaging 1 m tall (ranging from <1–7 m tall). The most common medium to short shrub associates include leatherleaf (Chamaedaphne calyculata),
Labrador tea (Ledum groenlandicum), bog rosemary (Andromeda glaucophylla), and bog willow (Salix pedicellaris). Scattered cedar, black spruce (Picea mariana), larch (Larix laricina), and red maple (Acer rubrum) reach heights of 5–7 m in the tall shrub layer.

The poorly developed herb layer is characterized by coastal sedge (Carex exilis) and less frequently round-leaved sundew (Drosera rotundifolia), royal fern (Osmunda regalis), pitcherplant (Sarracenia purpurea), rough-leaved aster (Aster radula), Pursh’s goldenrod (Solidago cf. purshii), buckbean (Menyanthes trifoliata), clustered marsh muhly (Muhlenbergia glomerata), Billing’s sedge (Carex trisperma var. billingsii), northern cotton club rush (Scirpus hudsonianus), and few others. Mosses include Sphagnum angustifolium, S. warnstorfii, S. magellanicum, S. rubellum, S. fuscum, Tomenthypnum nitens, Hylocomium splendens, Pleurozium schreberi, Aulocomnium palustre, and Dicranum undulatum.

A good example of this community occurs east of Umbagog Lake (Errol). 

Northern white cedar circumneutral strings occur as part of patterned fen systems.

northern white cedar circumneutral string (photo by Dan Sperduto for the NH Natural Heritage Bureau)
northern white cedar circumneutral string (drier portions on either side of center)
near Umbagog Lake in Errol (photo by Dan Sperduto)

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