Most if not all of PA forest was clear-cut in the early 1900's, so that in turn is just recently putting most of our forest in the mature stage. The amount of clear-cuts that are actually done in PA our very low compared to what we once did. So that is the major factor in the downward spiral in grouse population (lack of habitat). Deer do play a role in there browsing but that is on species such as oak and maple. We still get regeneration but it is birch, beech, and striped maple because deer do not desire these species. If more landowners would do more clear-cuts and less diameter limit cutting, such as 12 and up and high grades our forest and probably our wildlife would be a lot better off. But everyone is affraid to use clear-cuts as a proper management tool because they look bad.