Oze

Oze National Park was declared in 2007, separated out from Nikko National Park, of which it had formed part for decades. It lies at the point where the prefectures of Fukushima, Gunma, Niigata and Tochigi meet, in central Honshu, and protects the most extensive mountain wetland system in Japan.

Its core is Ozegahara, a raised bog at some 1,400 metres formed over an ancient lake basin dammed by lava flows from Mount Hiuchigatake, which at 2,356 metres is the highest summit in northern Honshu. Beside it lies Lake Ozenuma, likewise volcanic in origin. The bog is crossed by a network of wooden boardwalks that prevent trampling of an extremely fragile substrate, and its best-known image is the mass flowering of mizubasho, the Asian skunk cabbage, which in late spring covers the waterlogged areas in white.

Oze also holds a prominent place in the history of Japanese conservation. In the mid-twentieth century there were plans to dam the area for hydroelectric power, which would have flooded the bog; the public and scientific campaign that stopped the project is regarded as one of the founding acts of the environmental movement in Japan, and its later separation as an independent national park was the recognition of that value. Today the main management problem is a different one: the spread of sika deer, which graze the bog vegetation and alter its structure, forcing fencing to be installed and the population to be controlled.