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Ecological Communities

Appalachian oak-hickory forest

A hardwood forest with more than 60% canopy cover of trees that occurs on well-drained sites, usually on flat hilltops, upper slopes, or south and west facing slopes. Dominant trees include one or more of red oak, white oak, and black oak. Mixed with oaks, are one or more of pignut, shagbark, and sweet pignut hickory. Common associates are white ash, red maple, and hop hornbeam. Small trees include flowering dogwood, witch hazel, shadbush, and choke cherry. Shrubs and groundlayer flora are diverse. Shrubs include maple-leaved viburnum, blueberries, red raspberry, gray dogwood, and beaked hazelnut.

Beech-maple mesic forest

A hardwood forest with sugar maple and beech co-dominant. Found on moist, well-drained soils, on north and east facing slopes, and on gently sloping hilltops of any aspect, this ecological community type rarely occurs in ravines. Common associates are basswood, American elm, white ash, yellow birch, hop hornbeam, and red maple. Characteristic species in the sub-canopy are musclewood, striped maple, witch hazel, hobblebush, and alternate-leaved dogwood. There typically are few herbs and shrubs, but tree seedlings may be abundant. There are many spring ephemerals.

Cliff and talus communities on limestone

Open communities with less than 25% trees on a limestone or dolomite substrate. The Calcareous cliff community and Calcareous talus slope woodland communities are often found together. The woodland community is structurally intermediate between forests and open canopy upland of the cliff community.

Cliff and talus communities on shale

Open communities with less than 25% trees on a shale substrate. The Shale cliff and talus community and Shale talus slope woodland communities are often found together. The woodland community is structurally intermediate between forests and open canopy upland of the cliff and talus community.

Erosional slope/bluff

A sparsely vegetated community that occurs on vertical exposures of unconsolidated material, such as small stone, gravel, sand and clay, that is exposed to erosional sorces, such as water, ice, or wind.

Floodplain forest

A hardwood forest found on alluvial gravels on low terraces of floodplains of larger creeks and creek deltas. Characteristic trees include sycamore, cottonwood, box elder, silver and red maple, butternut, crack and white willow. American elm was once present. Characteristic vines and shrubs are Virginia creeper, poison ivy, and spicebush. Characteristic herbs are white snake root, green dragon, jewelweed, ostrich fern, and jumpseed.

Hemlock-northern hardwood forest

A forest that typically occurs on lower slopes of ravines, on cool, mid-elevation slopes, and at the edges of drainage divide swamps. Hemlock is a co-dominant species with one to three others: beech, sugar maple, red maple, black cherry, white pine, yellow birch, black birch, red oak, and basswood. Shrubs have low abundance, but striped maple may be present. Herbs characteristic of northern and montane areas are common.

Maple-basswood rich mesic forest

A hardwood forest that typically occurs on fertile, moist, well-drained soils. It is often associated with limestone or deep glacial gravels. Dominant trees are sugar maple, basswood, and white ash. Common associates are bitternut hickory, tulip tree, musclewood, alternate-leaved dogwood, and witch hazel. The shrub layer is sparse. Spring wildflowers are usually abundant. Characteristic species are trillium, white baneberry, spring beauty, toothwort, trout lily, and bloodroot.

Midreach stream

The aquatic community of a stream that has a well-defined pattern of alternating pool, riffle, and run sections. Waterfalls and springs may be present. Typical aquatic macrophytes include waterweed and pondweeds. Persistent emergent vegetation is lacking.

Mixed oak forest

A forest dominated by oaks found on steep south and west facing slopes. Soils may have calcareous materials at depth. Dominants are red, black, and white oak, and white pine. Black oak is an indicator of this ecological community type. Pignut hickory and red maple are usually present. Flowering dogwood and choke cherry are often abundant in the understory.

Riverside sand/gravel bar

A meadow community that occurs on sand and gravel bars deposited within, or adjacent to, a river channel. The community may be very sparsely vegetated, depending on the rates of deposition and erosion of the sand or gravel. Characteristic species include sandbar willow (Salix exigua), sand-cherry (Prunus pumila), dogbane (Apocynum cannabinum), switchgrass (Panicum virgatum), and poison ivy (Toxicodendron radicans).

Rocky headwater stream

The aquatic community of a small to moderate sized rocky stream with a moderate to steep gradient that lacks persistent emergent vegetation. The cold water stream flows over eroded bedrock near the stream origin and contains alternating riffle and pool sections. These streams typically have mosses and algae present, but few larger rooted plants.

Successional northern hardwoods

A forest with more than 60% canopy cover of trees that occurs on sites that have been cleared or otherwise disturbed. Dominant trees are usually two or more of the following: red maple, white pine, white ash, gray birch, quaking aspen, big-tooth aspen, and, less frequently, sugar maple and white ash. Tree seedlings and saplings may be of more shade tolerant species. Shrubs and ground cover species may be those of old-fields. In abandoned pasturelands apples and hawthorns may be present in the understory.

Successional old field

A meadow on sites cleared, plowed, and then abandoned. The ragweed type occurs on fields 1 to 3 years after last cultivation; ragweed, daisy, Queen Anne's lace, crab grass, golden foxtail, and chickweed are common. The goldenrod subtype occurs 3 - 15 years after last cultivation. Dominant species are perennial composites: goldenrods and asters. Other herbs include timothy, orchard grass, smooth brome, bluegrasses, quackgrass, sweet vernal grass, evening primrose, old-field cinquefoil, wild strawberry, and hawkweeds. Shrubs and trees represent less than 50% cover but include gray dogwood, arrowwood, raspberries, blackberries, sumac, red maple and white pine.

Successional shrubland

A shrubland with at least 50% cover of shrubs that occurs on agricultural fields 10 - 25 years after abandonment, following other disturbance, and especially on sites with restricted drainage. Characteristic shrubs include gray dogwood, raspberries, hawthorn, serviceberries, chokecherry, sumac, nannyberry, arrowwood and buckthorn. Herbs are those of old-fields. Seedlings of white pine, red maple and white ash are usually present.