In the Southern Unglaciated Allegheny Plateau ecoregion (Figure 2), five published studies have examined the vegetation-environment relationships of oldgrowth or relatively undisturbed forest ecosystems. Both McCarthy et al. (1987) and Braun (1950) report information on riparian forests of narrow ravines along small intermittent streams flowing through old-growth forest ecosystems.
McCarthy et al. (1987) classified the riparian forests of Hawk Woods in Athens County (Figure 2) as a mixed-mesophytic type, characterized by white oak (Quercus alba), northern red oak (Q. rubra L.), sugar maple (Acer saccharum), tuliptree (Liriodendron tulipifera L.), American basswood (Tilia americana L.), bitternut hickory (Carya cordiformis (Wangenh.) K. Koch), and yellow buckeye (Aesculus flava Ait.), and published stand structural information including the basal area and density of overstory and understory woody species, as well as woody species richness (Table 1).
Braun (1950) documented similar overstory composition for the former Morton's Woods in Gallia County (Figure 2), with the addition of American beech (Fagus grandifolia) which was a canopy dominant. No information on the riparian ground-flora composition or structure is available for either of these old-growth forests (Table 1).
In the western portion of this ecoregion, Braun (1928) characterized many early successional riparian forests of eastern Adams County as being dominated by sweetgum (Liquidambar styraciflua L.), which is eventually replaced by more shade-tolerant species such as American sycamore (Platanus occidentalis) and other mixed mesophytic species.
Similar results were reported by Runkle and Whitney (1987) at the Lake Katherine State Nature Preserve (Figure 2) where floodplains and terraces along smaller creeks are dominated by canopies of tuliptree (Liriodendron tulipifera), yellow birch (Betula alleghaniensis Britt.), river birch (B. nigra L.), and American sycamore (Platanus occidentalis) and an understory of American hornbeam (Carpinus caroliniana Walt.), northern spicebush (Lindera benzoin), umbrella-tree (Magnolia tripetala (L.) L.), American hazelnut (Corylus americana Walt.), pawpaw (Asimina triloba (L.) Dunal), and boxelder (Acer negundo).