Yambaru: A Rare, Biodiverse Environment
Yambaru is the northernmost region of Okinawa Island. Its interior consists of low but rugged mountains, some 80 percent of which are covered by rich subtropical forests. Such forests on the scale found in Yambaru are rare anywhere in the world at this latitude (close to 27 degrees N). Broadleaf evergreens predominate, thanks to the abundant rainfall produced by seasonal winds and the warm waters of the Kuroshio Current, which flows from the south.
Measuring 32 kilometers from north to south and 12 kilometers from east to west, Yambaru is a relatively undeveloped region compared to the rest of Okinawa Island. Despite its modest size, it hosts a surprisingly large variety of wildlife. Although the Yambaru region makes up only 0.1 percent of the total area of Japan, half of Japan’s bird species and a quarter of its native frog species are found here. The separation long ago of the Ryukyu chain from the Asian continent and the main islands of Japan led to unique paths in the development of many endemic species, including the endangered Okinawa rail, Japan’s only flightless bird, and the Okinawa woodpecker.
Yambaru’s dense forests shelter a wide range of plant species, from towering itajii chinkapin trees (Castanopsis sieboldii) to rare ferns and fragile orchids. Its mangrove forest supports various intertidal species while playing a critical role in maintaining the health of the coastal environment. This rich biodiversity makes Yambaru a key sanctuary for conservation efforts and a haven for nature enthusiasts interested in exploring its unique ecosystems.
