Tom Wessels, "Forest Forensics," got dropped in my stocking by Santa Claus. Neat little book interpreting visual clues to what has happened in the forest. Things like what happened to the white pine hit by lightning and why what appears to be the trunk is really a limb or evidence of a "nurse" log on the forest floor. The sort of thing that leads others in your group to think, "Wow, this guy knows more about the woods than anybody."