310 ECOLOGY 
SAND RIDGE CLAY BLUFF 
Cottonwood Aspen 
Gray pine Cottonwood 
Black oak Hop-Hornbeam 
White oak White oak 
Red oak Red oak 
Hickory Hickory 
BEECH AND SUGAR MAPLE 
Tulip Hickory 
Basswood Red oak 
White elm and Bur oak 
White ash 
Swamp white oak Basswood 
Buttonbush 
Hawthorn 
Cattail and Bulrush Slippery elm and 
White elm 
Water-lily and Water River maple 
Mill-foil 
Chara Black willow 
POND 
FLOOD-PLAIN 
Dr1acram 8.—Showing the convergence of four types of habitat, to the beech 
and maple forest. Read from the extremities toward center. (Prepared with the 
assistance of Dr. Cowles and from his writings.) 
