From the recreational perspective (summer hiking / back-country skiing) - the forests are night and day difference. Having a map of what has been logged and what has not often is the difference between forests that are easy to travel through and forests that are harder. A forest that was clear cut will have trees that are much denser and tightly packed together but tend to be smaller in diameter. These are very hard to travel through (hiking or skiing) compared with the old growth forests.

I don't know a ton about forest ecology but my sense is that trees that do the best are a function of what's already there and that it takes much longer than 100 years for the pre-clear cut conditions to return.

The Cedar River Watershed is not open to recreational use (it's a protected pristine watershed that supplies drinking water to Seattle and surrounding suburbs). The difference for that use is not relevant here.

A forest with larger trees and more extensive root systems will have a stronger effect than a forest with smaller trees with less extensive root systems.

Different tree species can also be more or less effective at functioning as a buffer. "Thirsty" trees typically do a better job of taking up water when it's wet and continuing to release water when it's dry. (Unfortunately, many new tree plantings favor more drought-resistant trees because they are easier to grow in clearcut fields, which are drier than forests.)

So, because I don't know much about this region specifically, these are my two questions:

Has there been a change in tree biomass in the region?

Has there been a change in the tree species makeup of the region?