168 
Ohio Biological Survey 
The vegetation of the lower part of the slope is even more mesophytic. 
But it belongs essentially to the ravine. 
Opposite the large ravine, a clearing succession of the same age is 
found on east and southeast slopes. The associations here are very 
similar to those of south and west slopes, but somewhat less xerophytic. 
An east exposure has a richer spring flora than the opposite west slope 
of equal steepness. The prevailing winds of this region are west-south¬ 
west, and their drying ef¥ect is evidenced in this difference in the vegeta¬ 
tion of slopes sheltered from and exposed to these winds. 
Fig. 35. A young bluff of clay and sand on the Little Aliami; annuals along the 
wet (dark) bands, older bluff association in center background, and flood 
plain associations to left. 
Thus, all the different exposures are exhibited in this limited area. 
The succession on the south slope is the slowest; the associations here 
the most xerophytic. While the associations of south slopes are still 
pioneers those of north exposures have progressed almost to a climax 
forest. 
