That is the simplest way I can possibly express the situation. Unfortunately, complexity needs to be added. For starters, forests are not merely a resource or a barrier to expansion. A lot of historians don't seem to address this issue. Forests are amazingly complex ecosystems, probably the most complex of all terrestrial ecosystems.
All forests are unique entities, and a single forest is very different as time passes.
Forests can be grouped into categories that may simplify this mental exercise. Older forests are dominated by well-established huge trees, and by a second layer of shade loving trees. Although growth and competition are less, they still exist. This discussion is giving non-tree forest citizens a bad deal. Of course the animal, plant, fungus, and insect populations are also of great importance to these complex dynamics, as they invoke their survival strategies in the endless struggle.