You are taking me back to my forestry 4-H project as a kid, but I think oaks are the final species in forest succession. Popular, birch, box elder - all the fast growing weedy trees colonize an area. Then the maples and oaks slowly move back in. This project was 25 years ago, so I probably forgot some things but that's my general recollection. You are seeing the beginning stages of the next oak forests starting.Rather the woods are repopulating with gray birch, beech, and poplar along the edges. I have nothing against these specie, but they just aren't the grand oaks.