It seems that one difference between the usage of 木 and 樹 is that while both mean tree, the former is also used to mean wood. My question is, is there a further distinction for living trees?
I'm reading 風の又三郎 and 宮沢賢治 uses both the characters 木 and 樹 for a living tree. For example in one passage
耕助(こうすけ)はうらめしそうに木を見上げました。
Then, 3 lines later, referring to the same tree,
耕助(こうすけ)は樹の下をはなれてまた別のやぶでぶどうをとりはじめました。
Is there some nuance I'm missing, or explanation for the choice of characters?
Update: (in case anyone is interested in why both were used in this text) naruto said in a comment below there is no reason to alternate between 樹 and 木, and pointed out only 木 appears in the 青空文庫 version. One possible reason for the use of both is that the manuscript was never finished by the author, and there were still inconsistencies in the original version, and that this is one of them (my version said it was minimally edited). Note this online 原文 uses both 樹 and 木 as I indicated above.