I often wonder how such foods become a part of our culinary landscape. A combination of fermentation gone wrong and winter desperation? A dare? A desire/need to waste nothing? I think there's also a kind of Nordic alcohol that is made from tree fermentation. It includes methyl alcohol, which is the stuff that can make you go blind. I can't find reference to it anywhere though, so maybe I've been lied to.
I don't know about fermenting trees, but lots of folk here in Norway drink hjembrent, or moonshine, especially out in the country. It's not legal, but popular none-the-less. In my part of Norway there's a local drink called karsk with a wonderful recipe: Place a one-krone coin in the bottom of cup. Fill with coffee until you can't see the coin anymore. Add moonshine until you can see the coin again. Enjoy! I got seriously messed up on karsk one night at a party way out in the country. It was terribly fun. And that one time was probably enough times for me!