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Joshin’etsukogen NP, Nagano
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Some Sugadaira slopes change jobs with the seasons: as snow melts, lettuce fields climb toward 1,350 m, then give way to ski runs again in winter. A local JA report counted about 70 growers in 2013.
Local hosts invited Hosei University’s rugby team to Sugadaira in 1931, hoping to draw summer visitors beyond ski season. The idea stuck: in 1967, Japan’s national team held its first training camp here.
Stone tools from sites on the Sugadaira Highlands are among the oldest traces of human life found in Ueda City, dating to about 20,000 years ago—evidence that people reached this high plateau in the Paleolithic.
Sugadaira was nicknamed Japan’s Davos in 1928. In 1976, it and Swiss Davos became sister communities and exchanged one tsubo of land each—about 3.3 m². The tower on Davos Hill marks this little-known link.
Soil evidence suggests Sugadaira’s grasslands may be about 4,000 years old. By 2010, however, 88% of the meadow area mapped in 1881 had disappeared, mostly as forest spread.
Beside Karasawa Falls, a rock shelter preserves traces from the Jōmon through Kofun periods. Excavations found pottery, stone tools and bone-and-antler implements—rare finds for inland Japan that drew national attention.
The name 菅平 likely comes from suge, the sedges growing thick in its central wetland. Older records also call the basin Numadaira, or marsh plain—a name that fits its soggy center.
Sugadaira Marsh shelters rare northern trees thought to be remnants of colder ice-age climates. Its sedge wetland is also home to Shinaimotsugo, a fish classed as Critically Endangered IA in Japan.
Sugadaira became part of a national park in 1949, yet grassland loss sped up: during the 1950s–70s it averaged about 1% a year, slightly faster than in the 1940s. Open meadows need ongoing care, not just protection on paper.
Long before paved roads, the Oosasa Highway crossed Sugadaira as a shortcut between Zenkoji and Edo. Officially recognized in 1651, it cut a day off the journey and carried travelers and goods over the mountains.
Scientists sampled 137 plant species in Sugadaira grassland and found abundant bacteria and fungi living in their roots and leaves. The meadow’s hidden diversity reaches far beyond what blooms above ground.
In 2024, researchers at Tsukuba’s Sugadaira station described a new nematode, Pristionchus seladoniae, repeatedly recovered from a local soil-dwelling bee—an unexpected new species in the tiniest neighborhood.
