Oh right, I just remembered that Norway did make something like “bark bread” in the past during famines, and that linked Wikipedia article says:
The inner bark is the only part of a tree trunk that is actually edible; the remaining bark and wood is made up of cellulose, which most animals, including humans, cannot digest.
i remember reading about how in some parts of the world (north America?) they used to process the wood of some trees to use as flour.
Humans do eat anything, I think the question should rather be "Can eating wood be nutritive or pleasant (or ethical 🤷)? "
Oh right, I just remembered that Norway did make something like “bark bread” in the past during famines, and that linked Wikipedia article says: