Presented here are brief descriptions of 35 naturally occurring vegetative cover types that were used to characterize prevailing vegetation of Ecoregion "sections" of the conterminous United States. Cover types may be visualized as the general, natural vegetation viewed from an aerial perspective. These cover types are used for descriptive purposes in the section narratives and should not be confused with potential natural vegetation (PNV), which was used in the process of identification and delineation of larger ecological units. Some cover types are similar to PNV, particularly in forested regions. Other cover types, such as the prairie type, are present only in small areas that have been changed to agricultural type. For example, cover types may result from exclusion of some types of natural disturbance, such as fire, and include planned disturbances, such as harvesting.
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WHITE-RED-JACK PINE
COVER TYPES
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Physiography
The white-red-jack pine cover type occurs generally on smooth to irregular plains and tablelands of northern Lake states and parts of New York and New England. More than 50 percent of the area is gently sloping.
Climate
Precipitation averages 25-45 inches annually and is distributed rather evenly throughout the year. Normal pan evaporation is 30-35 inches. During the frost-free season of 120-140 days, precipitation is roughly equal to evaporation.
Vegetation
Forests in which 50 percent or more of the stand is eastern white pine, red pine, or jack pine, singly or in combination, represent the white-red-jack pine cover type. Common associates include oak, eastern hemlock, aspen, birch, northern white-cedar, and maple. Much of this cover type is included in Kuchler's Great Lakes pine forest community.
Fauna
The white-tailed deer and black bear are the most common larger mammals in this cover type, and the moose inhabits the extreme northern portion. The woodland caribou formerly was abundant. In times past, the eastern timber wolf was very numerous and fed on small animals and the larger mammals just mentioned, but it has become very scarce and is classified as an endangered species.
The coyote, bobcat, great horned owl, and hawks are among current predators. The snowshoe rabbit and other small forest mammals are the main food source of the predators already mentioned. Spruce grouse and ruffed grouse inhabit the cover type. Porcupines inhabit parts of the cover type and become a problem in forest management when they are overly abundant.
Birds
Breeding bird populations average about 153 pairs per 100 acres. The black-burnian and the black-throated green warbler are the most abundant. Other birds include the whippoorwill, crested flycatcher, wood pewee, white-breasted nuthatch, veery, tanagers, ruffed grouse, great horned owl, pileated woodpecker, hairy woodpecker, downy woodpecker, blue jay, chickadees, red-eyed vireo, black-and-white warbler, ovenbird, redstart, black-throated blue warbler, hermit thrush, magnolia warbler, Canada warbler, yellow-bellied sapsucker, olive-sided flycatcher, red-breasted nuthatch, brown creeper, winter wren, blue-headed vireo, myrtle warbler, slate-colored junco, and white-throated sparrow. The endangered Kirtland's warbler occurs in limited areas.
Soils
The cool, moist soils are predominantly Spodosols. They have a low supply of bases and a horizon in which organic matter and compounds of iron and aluminum have accumulated, but they have no dense, brittle, or indurated horizon (Haplorthods).Soils of a significant proportion of the cover type are moist throughout the year and coarse textured,and they lack pedogenic horizons (Udipsamments).
Land Use
Nearly all of the land is forested and is used principally for lumbering and recreation. The associated cropland is devoted largely to growing potatoes and forage for dairy cattle. Large urban areas characterize the northeastern portions.
Data Source: United States Department of Agriculture, Forest Service
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THE SPRUCE-FIR
COVER TYPE
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Physiography
The spruce-fir cover type occurs on flat plains and tableland in the Lake and New England states and at high elevations in the Appalachian Mountains.
Subregions
Description of Ecological Subregions: Sections of the conterminous United States as far south as West Virginia. Except for some especially high places, local relief is almost entirely less than 500 feet and often less than 100 feet. More than half of the area is gently sloping.
Climate
Normal annual precipitation is 30-40 inches, half of which falls during the frost-free season of 120-140 days. Normal annual evaporation is 30-40inches. Evaporation is about equal to precipitation during the frost-free season.
Vegetation
Forests in which 50 percent or more of the stand is spruce or true fir, singly or in combination,characterize this cover type. Common associates include northern white cedar, tamarack, maple, birch, eastern hemlock, and eastern white pine.
Fauna
The fauna of the spruce-fir cover type is similar to that described for other northern conifer regions. A list of mammals at Mount Katahdin, Maine, includes moose, woodland caribou, lynx,marten, black bear, long-tailed weasel, white-footed mouse,and other mice and shrews. The moose, black bear, and white-tailed deer are the most common larger animals in the conifer areas.
Animals
The ruffed grouse is common throughout this cover type. The wild turkey may be found toward the south; the spruce grouse is found more to the north. The eastern timber wolf is considered an endangered species. Characteristic breeding birds of the cover type in the northeastern states are the olive-backed thrush, magnolia warbler, Cape May warbler, myrtle warbler, bay-breasted warbler, and white-throated sparrow. The density of territorial males may be as high as 430 per 100 acres.
Soils
The cool, moist soils of this cover type are predominantly Spodosols, although a large acreage of Histosols occurs in the Lake States. The Spodosols have a low supply of bases and a horizon in which organic matter and iron and aluminum compounds have accumulated. No dense, brittle, or indurated horizon is present (Haplorthods). The Histosols are wet, organic (peat and muck) soils.
Land Use
In the northeastern states, much of the area is forested. Lumbering and recreation are major uses of the forest. About 10 percent of the area is in crops or pastures. Most of the cropland is in forage crops for dairy cattle. In many cases farming is a part-time enterprise.
Data Source: United States Department of Agriculture, Forest Service
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THE MAPLE-BEECH-BIRCH
COVER TYPE
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Physiography
The maple-beech-birch cover type is best-developed in the New England States. Typically, it occurs on open high hills and low mountains. Only about 20-30 percent of the area is gently sloping. Ridges rise 500-3,000 feet above the broad valleys. Farther west, in the Lake States, the cover type occurs on irregular plains and tablelands. There, 50-80 percent of the area is gently sloping and local relief is normally 100-300 feet.
Climate
Mean annual precipitation ranges from 40-48 inches and is about 41 inches at central locations. The average annual snowfall of 72 inches covers the ground for about 87 days each year. The number of freeze-free days ranges from 120-150 per year. The mean daily maximum temperature is 24-36°F in January and74-80°F in July. The corresponding minimum temperatures are 4-18°F and 52-60°F. Potential evapotranspiration is 17-28 inches. The mean annual water surplus is 10-34 inches.
Vegetation
A forest is classified as being in this cover type when 50 percent or more of the stand is maple, beech, or yellow birch, singly or in combination. Common associates include hemlock, elm, basswood, and white pine.
Fauna
The white-tailed deer occurs throughout much of the maple-beech-birch cover type. The hardwood forest and the openings and farms within it provide food nd cover for a varied fauna. The black bear is present in many areas. The wolf is no longer common, but the red fox and gray fox are rather widespread, as is the bobcat. Several species of squirrels are in the forest, and a number of smaller rodents inhabit the forest floor.
The ruffed grouse is widespread, and the bobwhite inhabits the interspersed farmlands and forest openings. Songbirds include the ovenbird, red-eyed vireo, hermit thrush, scarlet tanager, blue jay,black- capped chickadee, wood pewee, and magnolia warbler.
Soils
Typical soils have a low supply of bases and a subsurface horizon that is dense and brittle but not indurated or that contains an accumulation of organic matter and iron and aluminum compounds (Fragiorthods and Haplorthods). Other major soils have light-colored surface horizons and a subsurface horizon that is dense and brittle but not indurated (Fragiochrepts).
Land Use
Much of the area is in farms. Feed grains and forage for dairy cattle are the principal crops. Potatoes are important locally. The steeper land is mainly forested, produces significant amounts of timber, and is an important recreation resource.
Data Source: United States Department of Agriculture, Forest Service
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