Great example: you can't (replace a forest). Whatever grows back, will be different from a previous untouched-by-humans state.

Same goes for a coral reef. And species depending on it, may disappear (perhaps permanently!) along with the coral itself.

It's really hard for that kind of process to evolve out, but some scientists are having success hardening coral in labs (so it'll reject algae less hastily) before releasing them into the wild