One thing I don't see talked about with reforestation, is that it's not enough to just plants trees. They are merely the most visible part of a forest, and alone die much quicker than when they are surrounded by all the constituents of a thriving forest: undergrowth, bushes, other types of trees, good soil, animals, bugs, etc.

Perhaps trees are just handy shorthand for "forest", but I think all the marketing pictures I've seen of reforestation projects are monoculture trees in rows, planted like a Christmas tree farm.