Once the trees are 15+ feet tall, they shade out the invasive species.  Plantation style forests are not so bad as many make them out to be.  Its just the usual back to nature irrational thinking.  In the midwest, a 1000 acre plot might be given over to corn or soybeans or whatever.  One rarely hears carping about plantation corn.  Trees are a resource like corn (except to environmentalists who live in the city).  To fight global warming we need maximum tree production and sequestration of the wood produced.