It really depends on the wording or the "terms" of the life estate and what you can do.  Without a doubt once the estate passes to you in fee simple you will have complete ownership rights to the property and the right to sell the timber as you please.  But if the life estate limits you in any way then you should not do anything.  Say you were not the remainderman - the person who gets the property after the life estate is over - and you did something to de-value the property during the life estate so that the remainderman gets less than expected.  That could be a problem under state law.  So even though you are the remainderman here I would double check with an attorney in your area by letting him or her read the documents involved.  Good luck.