Optional tree regrowth

Have an option during game setup for trees to regrow in unused areas over time. Areas where trees already exist repopulate faster. This would allow spoil piles and other slopes to gradually become forested. Areas where there is truck traffic and buildings (perhaps an area 10 tiles wide from buildings?) would not have trees grow. This would allow For “reclaimation” for those who want that. Might also include tree life span of 100-150 years? (That last part is far less important to me than the regrowth/regeneration). Have the rate be low enough that forestry towers are needed for major wood production.