Zack Smith is often quite brutal with reducing root systems and has good success collecting deciduous trees.. Though he is not collecting the same species. Beech are tricky. Hornbeam is also a little touchy, but not as difficult to collect as beech. Generally for trees like elm, where they are known for re-establishing root systems fairly easily, the aggressive cut back should have been okay, or "touch and go" but with a better than 50:50 survival rate. For beech that was probably too few in the root department.
