You're welcome, John. I hope the link answered your question.
I see that the link doesn't tell the title of the book. In case anyone is wondering, it's Chapter 2 of the "Wood Handbook".
It is one of my go to sources whenever I need to know something about wood.
Here is a link to the whole book.
Forest Products Laboratory -- Forest Service -- USDA
Your wonderful bark carvings have inspired me to try carving some bark too.
In the past, I've only considered bark as a hinderance to sawing logs up into lumber with my sawmill.