I would imagine your cypress depletion to be pretty localized. I know during WWII they depleted all the walnut out of several counties to be used as gunstocks. But, they grew back.
Industry will deplete a resource as quickly as possible. They then move on, and the resource will replenish itself. It's happened all over the Northeast.
This is the primary reason that people are up in arms about chip mills. We don't have any up here, since the resource isn't as suitable as southern pines. The industry comes in, gives a few jobs, depletes the resource, then moves on.
As for the armchair environmentalists, I've heard a lot of them speak. Most speak from a point of ignorance. But, we aren't judged by our words, just our actions.
I like to make as small of an environmental footprint as I can. Afterall, we're just kinda borrowing this place for a while, and I was always told to leave something borrowed in better shape than what I found it.