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Northern hardwood forest

The mean annual temperatures in the higher elevations in the Smokies are cool enough to support forest types more commonly found in the northern United States. The northern hardwood forests constitute the highest broad-leaved forest in the eastern United States. About 28,600 acres (116 km) are old-growth.

In the Smokies, the northern hardwood canopies are dominated by yellow birch (Betula alleghaniensis) and American beech (Fagus grandifolia). White basswood (Tilia heterophylla), mountain maple (Acer spicatum) and striped maple (Acer pensylvanicum), and yellow buckeye (Aesculus flava) are also present. The understory is home to diverse species such as coneflower, skunk goldenrod, Rugels ragwort, bloodroot, hydrangea, and several species of grasses and ferns.

A unique community is the beech gap, or beech orchard. Beech gaps consist of high mountain gaps that have been monopolized by beech trees. The beech trees are often twisted and contorted by the high winds that occur in these gaps. Why other tree types such as the red spruce fail to encroach into the beech gaps is unknown.