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Nikko NP, Tochigi
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The 176.7-km Kinugawa River begins in Kinunuma at about 2,040 m, then runs south to join the Tone River in Moriya. This quiet bog is the headwater of a major Kanto river.
At roughly 2,030 m, Kinunuma is widely described as Japan’s highest high moor. The protected wetland covers 13.4 hectares—an alpine bog small in area but exceptional in altitude.
Kinunuma is made up of about 48 pools scattered across peatland, rather than one large lake. These small waters are called chito—the characteristic pools of a high-altitude peat bog.
The park’s management plan identifies Kinunuma as the only place in Tochigi Prefecture where horomui-sō grows. A rare local botanical specialty is tucked among the marsh’s many familiar alpine flowers.
Kinunuma is important not only for its grasses and mosses: the Environment Ministry lists it as habitat for hosokawa-mozuku, a freshwater red alga, among the reasons this wetland is nationally important.
Inside Kinunuma’s deer-exclusion fence, 2024 monitoring found more flowers of the nationally listed rare orchid hime-suzumushisō—and confirmed fruiting, too.
Tochigi Prefecture records more than 100 alpine plant species at Kinunuma, alongside noteworthy dragonflies such as ruriboshi-yamma and Oze-ittonbo. This high bog is a habitat for insects as well as flowers.
Around Kinunuma, kurobe and asunaro trees grow in naturally stunted forms. These small conifers make an unusual border between the open peatland and the surrounding mountain forest.
A survey found deer-disturbed bare patches in the marsh. Because peat can wash away easily on this mountain slope, the report warned that plant recovery may be very slow.
