This forest occurs on moist, well drained (not soggy) soils and cover about 25% of Lewisboro on lower and mid-slope elevations. Good examples are found at the Brownell Preserve where sugar maples are tapped to make maple syrup. Sugar maple, red maple and beech trees are dominant. Other trees include white ash, black birch, black cherry, basswood and, in very moist areas, tulip trees.

The understory is usually made up of smaller sugar maple and beech saplings, hornbeam (ironwood), and sassafras trees. Witch hazel is a common shrub.

Soil is moist and has New York, lady and and interrupted ferns growing beneath the trees and, in sunlit openings, hay-scented fern.  The shaded, moist and less acidic soil here favors many spring ephemeral wildflowers including trout lily, trillium, toothwart and bloodroot, especially in places where deer do not commonly browse. Other plants include black cohosh, snakeroot, Solomon’s seal and violets along with beech drops near beech trees.

Birds found in this habitat include the ovenbird, wood thrush, scarlet tanager, veery and red-eyed vireos.  These migrating bird populations have plummeted over the last decades as their habitat here and in their overwintering locations in South and Central America have disappeared.