Natural Communities of NH -- Photo Guide

Red oak - black birch wooded talus  (S3S4)

Red oak - black birch wooded talus
communities occur below 1,600 feet in central and southern New Hampshire, and on lower elevation valleys of the White Mountains. The canopy has a sparse woodland to woodland structure. Red oak (Quercus rubra) is the dominant tree species, and is more abundant than northern birches, maples, and spruce (trees that collectively dominate the birch - mountain maple wooded talus community). Black birch (Betula lenta) is present; this tree is absent in higher elevation talus communities. Dry-site species, including ironwood (Ostrya virginiana), goldenrods, sedges, grasses, blueberries, maple-leaved viburnum (Viburnum acerifolium), and witch hazel (Hamemelis virginiana) are more prominent here than in more northern and higher elevation talus communities. Hardwood canopy and tall shrub compositions are variable, but nearly all have red oak in some quantity, though not necessarily abundant or dominant.

A very similar community, Appalachian wooded talus, occurs at even lower elevations or on warmer talus slopes in central and southern New Hampshire, but that one contains species with distinct southern affinities that are absent from this type. The red oak - black birch wooded talus community also has many species in common with the dry variant of rich red oak rocky woods but the latter differs by three factors: a woodland to forest structure; substrates of very rocky till with talus being less frequent or absent; and the presence of enriched-site indicators.

Talus in this community is derived from bedrock yielding soils that are acidic to weakly enriched and moderately nutrient-poor (submesotrophic). Rock types include the Littleton Formation, granites, monzonites, and quartzites.

Characteristic vegetation: R
ed oak (Quercus rubra) is the most constant tree species, but not always abundant. Other tree and tall shrub associates may include black birch (Betula lenta), sugar maple (Acer saccharum), American beech (Fagus grandifolia), ironwood (Ostrya virginiana), red maple (A. rubrum), mountain maple (A. spicatum), striped maple (A. pensylvanicum), yellow birch (Betula alleghaniensis), and occasionally pin cherry (Prunus pensylvanica). Paper birch (Betula papyrifera) and gray birch (Betula populifolia) may be occasional in gap areas. Softwoods are generally sparse or absent.

The shrub layer is also variable, and usually only dense in more open canopy areas (e.g., mountain maple thickets). It is usually characterized by some combination of the following shrubs: Hamamelis virginiana (witch hazel), Rubus spp. (raspberries and blackberries), Viburnum acerifolium (maple-leaved viburnum), Ribes spp. (gooseberries and currents), and Sambucus racemosa (red-berried elder). Vines (lianas) are more prevalent than in most till forests and may include Polygonum cilinode (fringed bindweed), Parthenocissus quinquefolia (Virginia creeper), P. vitacea (woodbine), Toxicodendron radicans (poison ivy), and Celastrus scandens (American bittersweet).

The herbaceous layer contains many species characteristic of most talus slope communities including Smilacina racemosa (false Solomon’s seal), Dryopteris marginalis (marginal wood fern), and Polypodium virginianum (rock polypody). In drier or more open areas, species such as Corydalis sempervirens (pale corydalis), patches or lawns of Carex lucorum/pensylvanicum (distant and Pennsylvania sedges), Oryzopsis asperifolia (rough-leaved rice-grass), Pteridium aquilinum (bracken), Solidago bicolor (silverrod), and S. caesia (blue-stemmed goldenrod) may be present (see also rich red oak rocky woods description for expanded list of dry vs. mesic species.) Common herbs of the region are also frequent, including Canada mayflower (Maianthemum canadense), wild sarsaparilla (Aralia nudicaulis), and starflower (Trientalis borealis). Foliose lichens are common on larger rocks.

Good examples of this community occur at Pawtuckaway State Park (Nottingham), Ellis Hatch Wildlife Management Area (Brookfield), Sundown Ledge (Albany), and Mount Stanton (Bartlett).

Red oak - black birch wooded talus
sometimes occurs as part of a temperate ridge - cliff - talus system.

Red oak - black birch wooded talus in Salisbury (photo by Dan Sperduto for the NH Natural Heritage Bureau)
red oak - black birch wooded talus in Salisbury (photo by Dan Sperduto)

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