Figure 5. Beech-maple-hemlock forests typical of riparian forests of the eastern Erie and Ontario Lake Plain.
The Erie and Ontario Lake Plain ecoregion (Figure 2) extends from the shores of Lake Erie in northeastern Ohio where the topography includes level highlands cut by ravines and develops into broader, flatter areas in the western portions, especially along the Maumee Drainage, commonly described as the Black Swamp. Data on riparian conditions for this ecoregion are available from six sources; however, only three provide information on riparian forest vegetation-environment relationships.
Williams (1936) described the North Chagrin Reservation of the Cleveland Metropolitan Park System in northeastern Ohio (Figure 2) as an area of high bluffs along the Chagrin River valley characteristically cut by short gullies and deep ravines. Williams also noted that no perennial streams run through the study area, but an excess of moisture is always present in the deeper ravines. The ravines might be considered the beginning of a transitional phase toward swamp forest or bottomland conditions where trees often represent bottomland species.
Some of the tree species encountered in the ravines included eastern hemlock (Tsuga canadensis (L.) Carr.), sugar maple (Acer saccharum), red maple (A. rubrum), white ash (Fraxinus americana), American elm (Ulmus americana), tuliptree (Liriodendron tulipifera), American basswood (Tilia americana), slippery elm (U. rubra Muhl.), northern red oak (Quercus rubra), flowering dogwood (Cornus florida L.), black cherry (Prunus serotina Ehrh.), black walnut (Juglans nigra), bitternut hickory (Carya cordiformis), and butternut (J. cinerea). Although Williams (1936) lists all herbaceous plants found in the study area, he did not categorize them by habitat type.
Schlesinger (1971) also found similar upland swamp forest communities along the sides and bottom of the large ravine cutting through his study area in eastern Cuyahoga County, but specific information on the vegetation from this area was not sampled or reported.
Vegetation-environment relationships of Goll Woods, the last known uncut old-growth forest remnant of the Black Swamp forest of northwestern Ohio, were studied by Boerner and Cho (1987). They found that the distribution of tree species was regulated by different drainage conditions. Species occupying the poorly drained flats were silver maple (Acer saccharinum), American elm (Ulmus americana), bur oak (Quercus macrocarpa), and ash (Fraxinus spp.). As drainage improves, these species were replaced by American basswood (Tilia americana), American hornbeam (Carpinus caroliniana), northern red oak (Quercus rubra), and red maple (Acer rubrum) on transitional sites adjacent to the drier beach ridges.
Sampson (1930), Braun (1950), and Gordon (1969) discerned the major influences of elevation, soil drainage, and aeration on forest composition when they delineated the Black Swamp lake plain into several similar regions. Kaatz (1955), in his historical description of the Black Swamp, described an area surrounding the settlers' route that crossed the swamp from southeast to northwest as low and wet, and being traversed by many streams. Here, the most frequently mentioned trees were ash (Fraxinus), elm (Ulmus), oak (Quercus), maple (Acer), basswood (Tilia), hickory (Carya), and cottonwood (Populus) species. Kaatz (1955) also noted that swamp forest species were highly sensitive to small variations in surface drainage which resulted in a great variety of species occupying the wetter sites, in contrast to the beech-maple or oak-hickory forest associations on better drained sites.