I think this may simply be a difference between written and spoken Japanese. But I've noticed that 木の皮 kinokawa is used regularly to mean "tree bark," while 樹皮 jyuhi appears to be more accurate but limited to signs or books or other written materials. Is 樹皮 used in daily conversation ever?
This question arises from trying to translate "birch bark canoe" (built by Northeast Native American tribes) and coming up with バーチ樹皮カヌー or something similar.
The difference is clear.
"Ki no kawa" is the originally Japanese word (and for that reason I wrote it in romaji) and 「樹皮{じゅひ}」 is a Sino-loanword.
「木の皮」 is far more intuitive for Japanese speakers and kids learn the word at least several years earlier than they learn 「樹皮」.
Accordingly, 「木の皮」 is an everyday word while 「樹皮」 sounds technical and academic. That is the case with most of the Yamato vs. Sino word pairs used in Japanese. Foreign-origin words get treated better in Japanese if I may generalize.
Regarding "birch bark canoe", IMHO, using 「木の皮」 would make it sound quite wordy and clumsy to our ears (partly because 「木の皮」 is actually three words even without "birch" and "canoe"). Something like 「カバ樹皮カヌー」 might look and sound better.
