Forester

I want to create a forester in my map; and because of that I need to know if it's possible to make an ability which makes that a forester plants trees...like the worker who cut the trees...and get wood

Hope you can help me

You'd need a dummy skill, which triggers (a trigger) to affect doodads (of type tree) in set area to return to life (stand anim).

Or if he meant something else, just use Create Doodad at a random point within X distance from the unit.