Two weeks ago the top of a huge maple tree on the edge of my woods broke off. I cleaned up the top, which had about 40 feet of trunk. Well, mostly. I still have to split it and shed it. Anyway I had to borrow my neighbor's chain saw with a 25 inch bar to fell the trunk, and that was still pretty difficult since it's a good 36 inches in circumference four feet up where I made the cut. It came down quite nicely though. I measured it at 32 feet so the total height of that tree was about 76 feet. It was senescent, with a hollow bole, and it was hollow where it broke off.
So that tree had reached its natural life span. I looked it up and that could be anywhere from 100 to 175 years depending on the environment. Since it was in the woods, away from any noxious environmental stress, I'd lean toward the high end. Since it was in a moist environment, it hadn't been defoliated by gypsy moth caterpillars, at least not since I've been here.
There are a few mature trees like that around. The predominant species is oak. I have one oak tree that's more than 4 feet in diameter. It has a long scar from a lightning strike but otherwise seems sound. Red oaks typically live 200 years but can live much longer. Most of my oak trees --
Oh, I just stopped to watch a red fox ambling through the woods --
Anyway, as I was saying, my oaks are mostly about 18 inches or so in diameter, some 24, I'm guessing a little over 100 years old. This land does not appear ever to have been farmed but some of it was evidently used briefly as pasture as there are stone walls. (The stone walls did not function as property dividers, as some people think, but just as a dump for rocks.) Anyway, what happened is that the New England forest was largely cleared for charcoal in the 19th century. They would leave a "grandmother tree" here and there, for shade and also to anchor the block and fall they used to pull stumps. That's what the big ones are. The forest regrew after petroleum largely eliminated the market for charcoal, so the math works out. This is a second growth forest but it's reaching maturity.
There are real problems however. Invasive species are number one. The woolly adelgids are killing the hemlocks, and outbreaks of gypsy moths have severely stressed the oaks. In fact there are so many dead oak trees along the roads them state has been out cutting them down and vast tracts of oak logs line route 14. The gypsy moth outbreak was more severe along the roads. As I say, in the deep woods they don't seem to thrive as much. Now we're threatened by the Asian long horned beetle, which hasn't made it here yet, and the emerald ash borer. The chestnuts and elms were wiped out long ago. The white birches were almost exterminated by a blight but there were some resistant trees and they've made a bit of comeback. I have a few, I'm happy to say.
I already mentioned the deer overpopulation as a major threat to the forest. Still, it's come back enough that the wildlife has recovered with it. We'll see how long it lasts.