This is a list of butterflies of Japan. About 327 species are known from Japan. Japan is home to a nine forest ecoregions, which reflect its climate and geography. The islands that constitute Japan generally have a humid climate, which ranges from warm subtropical in the southern islands to cool temperate on the northern island of Hokkaidō. The terrestrial ecoregions are: The most important and threatened butterfly habitat in Japan is Satoyama a Japanese term applied to the border zone or area between mountain foothills and arable flat land.