Yambaru: A Rare, Biodiverse Environment
Yambaru is the northernmost region of Okinawa Island. Its name is traditionally written with Japanese characters meaning “mountains and forests.” Yambaru’s interior consists of low mountains, some 80 percent of which are covered by lush subtropical forests. Such forests on Yambaru’s scale are rare anywhere in the world at this latitude of close to 27 degrees N (shared by the Libyan desert, northern Mexico, and northwestern India). The broadleaf evergreen forests proliferate here due to seasonal winds and the warm Kuroshio Current that flows north from the Philippines. These factors combine to create the cloud formations that bring plentiful rainfall to the mountainous terrain.
Measuring 32 kilometers from north to south and 12 kilometers from east to west, Yambaru is relatively undeveloped compared to the rest of the 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 the bird species and a quarter of native frog species in Japan 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 of development of many endemic species, including the endangered Okinawa rail (Japan’s only flightless bird), the Okinawa woodpecker, and the Yambaru long-armed scarab beetle.
The wide range of plant species in Yambaru’s dense forests includes towering itajii chinkapin trees (Castanopsis sieboldii), rare ferns, and fragile orchids. A mangrove forest on the east coast supports various marine and plant 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 with an interest in exploring its unique ecosystems.
