https://en.wikipedia.org/wiki/Coppicing the technique is widely known.
not every coppiced tree can be convinced to grow straight, though.
not every coppiced tree can be convinced to grow straight, though.
It's an interesting one to discuss with arborists. In North America, there isn't a long history of pollarded trees, so the technique is generally frowned upon since it's essentially "topping", a universally derided pruning method.
European arborists who maintain historical trees are more familiar with pollarding, and commonly are asked to explain why they believe their continuance of topping is defensible as a modern or scientific technique in the care of trees.
You could claim sort of convergent evolution, but I find it hard to believe that a 1500 year old Roman cultivation technique was reinvented in Japan almost exactly at the apex of China's naval power. This smells of corporate espionage.
Also, how would Chinese naval power help Japanese foresters learn a new technique for pruning trees?
> Also, how would Chinese naval power help Japanese foresters learn
A bit rusty on my Asian history, but cultural exchange between China and Japan has been going on for millennia. Writing, food (rice imported 500 BC), culture, religion. It wasn’t until the mid 1600’s that Japan shut down and did their own thing.
I'd place reasonable odds that coppice/pollard are older than the written word. In fact this is probably middle stone age technology. How many decent spears can you make without pollarding? Let alone arrows, which you would need ten times as many of...
Since Japan appears to have already had long bows before recorded history, it's probably more accurate to say this particular variant of pollarding in Japan dates back 600 years, and is tuned specifically for creating posts (and beams?) which are defining elements of Japanese architecture. Pollard is great for making spears and staves, good for making fences (up to and including the posts), but not so great for making houses.
Perhaps my sense of scale was off in the pictures, but I could easily see poles that size used for secondary beams.