Natural Communities of NH -- Photo Guide

Alder wooded fen  (S3S4)



Alder wooded fens
 can be thought of as a “boggy alder swamp” community. They are dominated by speckled alder, various other shrub associates, and sometimes scattered conifers. They occur in open headwater basins, in somewhat seepy subacidic fens, and along small low-energy streams (e.g., first and second order streams), all of which are lower-energy settings relative to other alder-dominated communities. The community has fewer heath shrubs [e.g., rhodora (Rhododendron canadense) and Labrador-tea (Ledum groenlandicum)] than similar montane alder - heath shrub thicket communities described from the White Mountains. Shallow to deep muck or peat soils are typical. This is a broadly distributed community type abundant in the White Mountain and North Country regions.

Characteristic Vegetation: Speckled alder (Alnus incana ssp. rugosa) dominates. Other characteristic shrubs found lower abundance include red osier dogwood (Cornus sericea), mountain holly (Nemopanthus mucronatus), mountain fly honeysuckle (Lonicera villosa), meadowsweet (Spiraea alba), steeplebush (S. tomentosa), witherod (Viburnum nudum var. cassinoides), swamp red currant (Ribes triste), and skunk currant (R. glandulosum). Herbs and dwarf shrubs are common and include three-seeded sedge (Carex trisperma var. trisperma), crested wood fern (Dryopteris cristata), spinulose wood fern (Dryopteris carthusiana), three-leaved false Solomon's seal (Maianthemum trifolium), dwarf raspberry (Rubus pubescens), silvery sedge (Carex canescens), prickly sedge (C. echinata), oak fern (Gymnocarpium dryopteris), and violets (Viola spp.). Trees generally contribute less than 25% cover and may include black spruce (Picea mariana), balsam fir (Abies balsamea), larch (Larix laricina), northern white cedar (Thuja occidentalis), and gray birch (Betula populifolia).


Good examples of this community occur at South Bay Bog (Clarksville) and Sweat Meadow (Errol).

Alder wooded fens
sometimes occur as part of larger medium level fen systems, black spruce peat swamp systems, and near-boreal minerotrophic peat swamp systems.


alder wooded fen along Cascade Brook in Pittsburg, NH (photo by Dan Sperduto for the NH Natural Heritage Bureau)
Alder wooded fen along Cascade Brook in Pittsburg, NH (photo by Dan Sperduto)

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