Here is "The Seeds we sow" - a documentary about Takachiho. Which I have only just started watching myself, but it looks really good, too.
(And, since I have spare space: Studio Ghibli films are just about the most wonderful films about human-nature relations. #MyNeighbourTotoro, #PrincessMononoke, #Ponyo, #Nauticaa - all brilliant)

https://www.youtube.com/watch?v=7LXqoYyQZYU