What's wrong with the Eastern forests? What's being done?

Question

On a recent trip across Pennsylvania and Ohio, I noticed that many trees are dying and that the invasive tree of heaven seems to be taking over.

What is wrong?
Is anyone doing anything?
What can be done?

Answer 1

There's all sorts of problems: drought (recently), acid rain and other atmospheric pollutants, introduced insects and pathogens, and skyrocketing deer populations that eat young trees faster than they can reproduce. There's probably other important problems as well.

Is something being done? These are pretty complex problems that require regional efforts. Not much can be done to stop the introduced pathogens and insects. Acid rain is a perpetual problem with no end in sight. State wildlife agencies are attempting to reduce deer herds with little success.