1. Make it so that chance of tree sprouting depends on biomes, for example:
Forest biomes are good place for trees, there must be a lot of seedlings, dense forests
Dry places just like moor will have less seedlings.
Grass must have maximum chance, because it's have maximum unused resources without competition: water, minerals, and sun. This will make empty spaces from ruined camps regrow trees faster.
2. After player camp gets destroyed, nature takes it's pavement away, it will leave this ugly thing in map:

Make it so that fresh tree seedlings will check natural biome of the parent tree, and terraform grass to it's biome in 3-5 tiles radius during growing.