Ecology of the Cincinnati Region 
187 
saccharumj, sour gum (Nyssa sylvatica), shell-bark hickory (Carya 
ovata), and white-heart hickory (Carya alba). 
The most striking feature of this area, as well as of the valley of 
upper Mill creek, and the Little Miami-Miami valley, is the absence of 
beech. It is found neither on the flats nor on the slopes. The forests, 
though mesophytic, are far from either climax type. 
V. THE ELOOD PLAIN SERIES 
In places along the ravine course, small areas of flood plain with 
their attendant vegetation were noted. Along the rivers of the region, 
flood plains are sometimes several miles wide. The vertical range is 
greatest along the Ohio, which has an annual variation in height of about 
sixty feet. It is the flood plains of the larger streams—the Ohio, Miami, 
Little Miami, and Licking rivers, and Mill creek—which constitute one 
of the four great topographic and vegetational areas of the region. Along 
these rivers, flood plain vegetation reaches its greatest development. 
Although the beach-like shore and the islands are genetically a part 
of the flood plain, it is convenient here to separate the frequently sub¬ 
merged and open shore associations from the closed associations of the 
broad and higher flood plain. 
A. THE BEACH-LIKE SHORES 
The river shores here discussed are comparable to lake beaches 
(Cowles, 1899). Their vegetation is controlled by a similar set of fac¬ 
tors, most important of which are topography, moisture, and varying 
river stages. The latter aids in producing zones comparable to the 
wave zones of lake shores, but as the motion of the water is slower, the 
corresponding zones usually have more plants. 
The lower part of the shore—the first vegetation zone—is submerged 
many times each year and not infrequently during the growing season. 
It may be compared with the lower beach of lakes, although it usually 
supports a scant growth of annuals, most of which are hydrophytes. 
A higher part—the second vegetation zone—corresponds to the mid¬ 
dle beach, with its xerophytic annuals. This is not often submerged 
except during the winter and early spring. 
That part of the Ohio river affected by the Fernbank dam (Dam 37) 
has a nearly constant summer height. Here the lower shore is con¬ 
stantly submerged, and consequently the first vegetation zone is almost 
