"Timber rights" means that
at any time, he can contract out to have somebody come in and cut the timber.
He would keep the cash from the sale, and you could be left with a messy, barren piece of
land.
I would suggest having a lengthy conversation with your lawyer about this. If it is "selective cut" they take the best (most valuable)
trees and leave the scraggly ones behind (this then becomes your gene pool for regrowing the forest...which he can later come back and cut again!).
Or worse yet (if it is allowed in your region), it can be a "clear cut" which means that they chop them ALL down. They usually leave a horrendous mess behind once the valuable timber is gone.
Sorry. I don't know how to 'sugar coat' this: If he has timber rights, he
owns every tree on the property!
Hope that it works out well for you.