PD is spot on.
Tree growth is more dictated by the crown or leaves than anything. They are the "solar panels" that make food for the tree. My experience is a tree that has a full crown or it's crown is part of the overall canopy of the woods will have wide growth rings until it matures and is at the end of life and slows growth.
This is why foresters do timber stand improvement. Removing competing trees of crop trees to allow crown expansion thus increasing wood production.
Now, the other consideration is soils and water. Some soils are able to retain water better and support trees, some are thin and poor and only support grasses with scattered "stunted" trees.. These will have thin rings too, even though the crown may be full..
Red elm and American elm are typically found more in riparian areas (near streams). When they grow "off site" they can and tend to be much slower growing. Black walnut is similar in that it will be knotty and slow growing on a dry ridge compared to a bottomland.