Question
Hello Jim, I'm considering buying Birch bark skins from a lumber yard in northern New England, and was curious about the safety of the process for the trees - in what instances are they harmed? Are there cases of standing dead trees that make it more sustainable? And how about de-limbing branches for decorative or architectural use - are those process' more or less benign than skinning the bark? Thanks - Alan

Answer
If you are getting these from a lumber yard they more than likely came from cut tree or logs. You can harm standing living trees IF you cut the bark into the cambium layer (usually green in color) and cut bark all the way around the trunk and this will girdle the tree and kill it. You can safely cut the loose bark off paper birch without harming the tree. Pruning branches from a tree will not harm it as long as long as you leave at least 1/3 to 1/2 of the live branches on the tree. Dead branches can be cut off with no problem to the tree. Here is a web link about paper birch nark peeling.
http://nrd.kbic-nsn.gov/PDF/GatheringHarvestingUseofBirchBark.pdf