Fall Creek Plateau
The Fall Creek Plateau was once a floodplain of Fall Creek, but now the creek bed has been eroded to a lower level, and the site is rarely subject to flooding. The rich and gravelly soils, typical of floodplains, support a diverse forest. On the Fall Creek Plateau, the species composition with ancient beeches, hemlocks, and sugar maple dominant is archetypal of pre-settlement forests in the Northeast. Some of these trees may be 400 years old. Other species found here that are typical of rich, well-drained sites include red oak, white oak, cucumber magnolia (Magnolia acuminata), tulip poplar (Liriodendron tulipifera), and basswood. Near the water's edge, sycamore is abundant. The herb layer is rich and diverse. A number of locally rare or scarce plants grow here, as well as in the gravelly floodplain of the Mundy Wildflower Garden.
The steep north-facing slope between Fall Creek and the arboretum is magnificent mature forest. Hemlock, basswood, sugar maple, white pine, and red oak are dominant. Black cherry (Prunus serotina) and beech are also abundant. There is a small section planted with Scots' pine (Pinus sylvestris), red pine (P. resinosa), and Norway spruce (Picea abies). A patch dense with sassafras (Sassafras albidum) sprouts is found at the western edge of the forest, near the stairway. The herb layer is surprisingly rich throughout this forest; blue cohosh (Caulophyllum thalictroides), ferns, and mayapple (Podophyllum peltatum) are very abundant.