This beech (left) and the tulip poplar next to it have obviously not heard of the dictum that species are supposed to compete with each other. This picture doesn't reveal that they are both about equally tall and, so far as I can tell, equally healthy. That they have grown so well so far is an indication that they are actually tolerating each other.
Then again, maybe they are in a fierce competition. It's hard to tell what's going on high up in the intertwined canopy or deep among the tangled roots.