Of course you know, if you strip the bark off all the way around you'll kill the tree. But if you take a strip just from one side of the tree, which was what the early people did, the tree will continue to thrive for many years. (Apparently, though, the "second growth" of bark the following year has special properties - don't remember what they were, I'm afraid - and the Indians would often deliberately strip the bark off the tree one year, then come back and take the second growth bark that had covered the injury the next. This would kill the tree - but I guess in those days, there were more birch trees than there were people so it didn't have much impact on the environment.)

But you're right, the bark needs to be taken from a live tree. Birch bark off a dead tree makes good firestarter, though. <img src="/images/graemlins/smile.gif" alt="" />