This is an ancient Japanese Sustainable forestry technique called โ€œdaisugiโ€. It allows for lumber production without cutting down trees.

Specially planted Cedar trees are pruned heavily * (think of it as a giant bonsai) to produce shoots that become perfectly uniform, straight and completely knot free lumber.

Source: Ancient Japanese lumber production method without cutting down trees called โ€œDaisugiโ€

The Japanese continue to astound me.