A bunch of young trees don't equate to old growth forests in any sense and it's even worse if the species hasn't evolved in in balance with that environment's other species and conditions.
So it's not even just that the tree needs to survive. On top of that we need to put time and resources into the right mix of regionally native trees which will thrive and integrate into their surroundings to properly reform ecosystems over numerous decades that we don't even have.