Ecology of the Cincinnati Region 
133 
is found on the surface in but few places. Such a forest does not, how¬ 
ever, seem to succeed the pin oak forest, but rather to occupy areas which 
always have been different. Either a pin oak or a white oak forest may 
pass directly into a beech forest. 
In the advancing mesophytic forests, white oak rapidly drops out 
with the other hydrophytic trees. In the ultimate mesophytic forest of 
this succession, it forms no part. It will be shown later, that white oak 
is a character tree in the xero-mesophytic associations of slopes. It is 
Fig. 13. White oak tree (Quercus alba) in the upland hydrophytic forest near 
Bethel; a hummock of mosses built up around it. The lighter patches 
are Sphagnum. 
equally characteristic of these two opposing types of forest. Possibly 
it may be considered as the ecological equivalent of some of the conifers; 
for example, white pine, and to take the place of such trees in this region. 
Mixed forest .—Contrasted with the almost monotonous forest of the 
pin oak type, are the mixed woods found upon many parts of our up¬ 
lands. What evidences of succession there are indicate that these mixed 
hydrophytic forests probably were once similar to the more extensive 
forests previously discussed, and that they are rapidly becoming more 
mesophytic. 
