The New Hampshire Natural Heritage Inventory identified the following plant communities as “exemplary natural ecological communities:”
Southern New England Acidic Rocky Summit/Rock Outcrop (Walpole)
This acidic woodland community is found on warmer rocky ridges at low to mid elevations in central and southern NH and is characterized by the prominence of species with decidedly southern affinities. Some NH occurrences are transitional, exhibiting floristic compositions characteristic of both Appalachian and northern influences. Red oak tends to be consistently present in quantity along with a variable presence of other trees including white pine (Pinus strobus), red pine (Pinus resinosa), pitch pine (Pinus rigida), white oak (Quercus alba), black oak (Quercus velutina), chestnut oak (Quercus prinus), shagbark hickory (Carya ovata), eastern red cedar (Juniperus virginiana), sassafras (Sassafras albidum), and ironwood (Ostrya virginiana). Common shrubs include scrub oak (Quercus ilicifolia), early low blueberry (Vaccinium angustifolium), late low blueberry (Vaccinium vacillans), bush honeysuckle (Diervilla lonicera), black huckleberry (Gaylussacia baccata), and bearberry (Arctostaphyllos uva-ursi). Open glades and patchy tree canopy support a variety of plant associates with herbaceous species including Pennsylvania sedge (Carex pennsylvanica), hairgrass (Deschampsia flexuosa), hay-scented fern (Dennstaedtia punctilobula), little bluestem (Andropogon scoparius), corydalis (Corydalis sempervirens), bastard toadflax (Ommandra umbellata), dwarf dandelion (Krigia virginica), silvered (Solidago bicolor), pussy toe (Antennaria plantagifolia), marginal woodfern (Dryopteris marginalis), false Solomon's seal (Smilacina racemosa), rock polypody (Polypodium virginianum), false fern-leaved foxglove (Aureolaria pedicularia var. intercedens), sweet-scented goldonrod (Solidago odora), and abundant lichens and mosses.
Central New England Dry Transitional Forest on Acidic Bedrock and Till (Walpole)
Dry to dry-mesic forest of coarse till, sandy or shallow-to-bedrock soils, with overstory composition of red oak and white pine. As defined here, the type includes forests dominated by either or both species. White pine appears to be more predominant on many of the dryer sites. This community may grade into oak-pine rocky summit woodland communities.
Southern New England Floodplain Forest (Walpole)
Floodplain forests characterized by silver maple in NH occupy regularly flooded alluvial terraces along margins of major rivers. This is a broadly defined community as considerable floristic variation exists between high and low floodplain resulting from differences in the periodicity, intensity and duration of flooding. Deposition and erosion in the river channel through time generates successive point bars, particularly on meanders. A ridge and swale topography results with bands of vegetation corresponding to the flood regime.
Low flood plain forest is remarkably consistent throughout the northeast and is composed of silver maple (Acer saccharinum) canopy with hackberry (Celtis occidentalis), eastern cottonwood (Populus deltoides), boxelder (Acer negundo), and american elm (Ulmus americana) occurring as associates, particularly along the riverbank. Common herbaceous species include ostrich fern (Matteucia struthiopteris), stinging nettle (Urtica diocea), false nettle (Boehmeria cylindrica), wood nettle (Laportia canadensis), Jack-in-the-pulpit (Arisaema triphyllum), sensitive fern (Onoclea sensibilis), bladdernut (Staphylea trifolia), poison ivy (Toxicodendron radicans), white snakeroot (Eupatorium rugosa), Osmunda spp. and various shrubs.
Low flood plain forest is remarkably consistent throughout the northeast and is composed of silver maple (Acer saccharinum) canopy with hackberry (Celtis occidentalis), eastern cottonwood (Populus deltoides), boxelder (Acer negundo), and american elm (Ulmus americana) occurring as associates, particularly along the riverbank. Common herbaceous species include ostrich fern (Matteucia struthiopteris), stinging nettle (Urtica diocea), false nettle (Boehmeria cylindrica), wood nettle (Laportia canadensis), Jack-in-the-pulpit (Arisaema triphyllum), sensitive fern (Onoclea sensibilis), bladdernut (Staphylea trifolia), poison ivy (Toxicodendron radicans), white snakeroot (Eupatorium rugosa), Osmunda spp. and various shrubs.
Descriptions from A Classification Of The Natural Communities Of New Hampshire, 1994 Draft, Natural Heritage Inventory, by Dan Sperduto