Information about "life" in the tree canopy was very interesting and fascinating - up to a point. The descriptions about lichen and other plant life in the canopy contained too much detail for the average reader - I glossed over many of these parts. While the author did an admirable job of interleaving detailed scientific sections with stories about the people involved in exploring the trees so that the reader did not get too bored, I felt there were too many side characters (in addition to the main ones) that got introduced and I couldn't keep them straight. As a non-fiction book, this was one of the better ones I have read. As I mentioned, the subject matter was fascinating and educational and the author did a great job of adding elements of suspense at several times in the book as he described a number of dangerous incidents that occured during the climbing of the trees.