This is an idea for a mod where nature in minecraft regrows. lets say i had a city, after a while nature would start to regrow like grass, moss, and vines would grow over buildings and even roads could be covered in dirt even if theres a glowstone it could turn into a red stone lamp turned off, or a torch would disapear maybe even have the mod slowly eat away buildings.
Uuuh, I beleive it already happens in Minecraft. It just happens at a slow pace. If you want nature to grow back faster, get sapplings and bone meal, plant a sappling and right click some bone meal on it. Right click bone meal on the ground and you will have tall grass and flowers. As for vines, they do grow over buildings at a somewhat slow pace. Try bone meal again here.