Natural Communities of NH -- Photo Guide

Meadowsweet - robust graminoid sand plain marsh  (S3S4)

Meadowsweet - robust graminoid sand plain marsh
is restricted to the southeastern part of the state. The community occupies a position downslope of drier, tall shrub thickets and upslope of wetter, short herbaceous communities. The vegetation is taller than other herbaceous basin marsh types, and the composition is reminiscent of a fen. The growth of peat mosses is prolific during wet periods, which can last for years, but decomposition during drawdown periods precludes the build-up of organic matter. 

This is a broadly defined, seasonally-flooded community found in closed-basins on sand plains. It is dominated by various robust perennial graminoids, medium shrubs, and Sphagnum mosses. Dominants vary among examples but consist almost entirely of common, widespread wetland species with affinities to seasonally flooded poor fens and alluvial meadow marshes. However, this community has shallower peat and muck horizons (over sand) compared to fens, more broadly fluctuating water levels than both fens and alluvial marshes, and no over-bank or surface water flow-through typical of alluvial marshes. It is typically positioned between drier tall shrub thickets and various wetter, short graminoid and forb communities.

Soils are mostly shallow peat (5 cm) and shallow sandy muck A horizons (5–20 cm) over sand. Dulichium-dominated examples have peat up to 50 cm over 5–30 cm of mucky sand over sand.

Characteristic Vegetation:
A mix of robust perennial graminoids, shrubs, and aquatic peat mosses characterize this community. Meadowsweet (Spiraea alba) is frequent and often a dominant; Sphagnum moss is abundant (mostly Sphagnum cuspidatum). Robust, cespitose (tussock-forming), and rhizomatous perennial graminoids are constant as groups. Rhizomatous species include frequent three-way sedge (Dulichium arundinaceum)(aerenchymatous) and tussock sedge (Carex stricta var. strictior), and occasional wire sedge (C. lasiocarpa) and bottle-shaped sedge (C. utriculata). Cespitose species include rattlesnake mannagrass (Glyceria canadensis), bluejoint (Calamagrostis canadensis), and woolly bulrush (Scirpus cyperinus). Large cranberry (Vaccinium macrocarpon) and leatherleaf (Chamaedaphne calyculata) are the only other occasional shrubs. Swamp candles (Lysimachia terrestris) is a near constant in low abundance, but other forbs are sparse and mostly represent spill-over from adjacent zones. 

Three-way sedge - mannagrass mudflat marsh shares some species with this community, but has much less Sphagnum moss and meadowsweet, very few tussock-forming graminoids, and more short graminoids and forbs.

One occurrence of this community forms an unusual association for the state. It consists of a dense two-acre stand of solid three-way sedge and Sphagnum cuspidatum to the near exclusion of all other vegetation, with a patch of sharp-flowered mannagrass (Glyceria acutiflora) shallow peat marsh in one small pool area.

A good example of this community occurs at Grassy Pond in Litchfield.

Meadowsweet - robust graminoid sand plain marsh may occur as part of a larger sand plain basin marsh system.

(sorry -- no photo available)

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