You are back in the midst of the OAK-HICKORY FOREST.  Often, young oaks and hickories do not grow well in the forest's shady interior, and the presence of these young trees in this forest is quite limited.  Instead, there is a healthy population of young black cherry, hackberry, elm, and basswood.  Occasionally, one of these grows very large, but generally, the tops of these trees make up the higher understory, which is the layer right below the canopy (the highest layer).  These species compete well in crowded, shady conditions.  Most of these trees are now of medium size, and when openings in the upper canopy occur, they will fill in the gaps.  Over the next several decades, the composition of this forest will change dramatically.  There will be more trees, more kinds of trees, and more medium-sized trees.  The giant oaks that now provide the very upper reaches of the forest canopy will diminish.