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The Southern
Appalachian Region can be identified as containing 3 separate physiographic
provinces:
the Blue Ridge,
Ridge and Valley, and
the Cumberland Plateau.
Elevations,
for the most part, lie between 1000 to over 6000 feet above sea
level in the region.
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The
Cumberland Plateau in TN
and AL contains mostly mesophytic hardwood forests over limestone
or sandstone rock substrates. Elm. Hackberry, Ash, Sugar Maple,
Hickory, Chinkapin Oak, and Scarlet Oak are common canopy species.
Some endemic or uncommon species typifying this and the next province
include Neviusia alabamensis, Conradina verticillata, Cotinus
obovatus, Fraxinus quadrangulata, Ulmus serotina.
The
Ridge and Valley Province
lies just eastward of the Cumberland Plateau. It is characterized
by long, narrow ridges oriented northeast by southwest, with deep,
narrow valleys between. Vegetation and rock substrates are sufficiently
similar to that of the Cumberland Plateau that references made to
a plant's habitat on the Plateau can often be assumed to apply to
the Ridge and Valley Province as well.
The
Blue Ridge forms the easternmost
ranges and escarpment of the Southern Appalachians, characterized
by more irregular topography than the western provinces, and metamorphic
rock substrates of acidic to neutral pH ranges. The predominantly
acidic soils favor more forests rich in oak or oak- conifer communities,
with ericaceous understories. Since the disappearance of the province's
most characteristic canopy species, the American Chestnut, some
of the important community types of present-day forests are described
on under Plant Communities.
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