How would one manage the state of static living things like trees in a large sandbox world? Trees in Minecraft, for example: They grow even when the player is far away.
One way is to save them with a timestamp as they go "out of range" and stop updating them in the usual way. Then re-instate them with a sensible state by running an update with a delta time of the time elapsed since that saved time.
I'm planning a new prototype but this has me a bit stumped.