I did a fun experiment in my yard, I took a small mixture of grass seeds (store bought bird seed) and planted them in various places in the yard (after sprouting). It was amazing to see what did and did not thrive in various places due to sun, water and soil.

One place supported all 4 kinds, the other three only supported 1 or 2 kinds of grasses.

I would think reforesting a barren land might have to take multiple phases of growth to prepare the soil, ability to hold water, fungal colonies to extract nutrients, etc.