Incredible author, he's written some scary stuff on everything from ebola to cobras to bioterror to.....redwoods! so what up with that? it seems that he tired of the horrific nature of his other work, though that's not clear.
he spent much of the time talking about redwoods, which are near and dear to me having spent 7 years of my life living amongst them. that being said, i never would have actually thought about climbing one, yet he's climbed the tallest. he has found berries, mosses, lichen and all kinds of interesting other life.