The Natural World Heritage Site of Amami-Oshima Island, Tokunoshima Island, Northern Okinawa Island, and Iriomote Island
The islands of Amami-Oshima, Tokunoshima, Iriomote, and the northern part of Okinawa were registered as a Natural World Heritage Site by UNESCO in 2021. The designation was made to protect the biodiversity and habitats of many endemic and globally threatened species. The four islands are part of the Ryukyu chain that stretches some 1,200 kilometers from the southern Japanese island of Kyushu almost to Taiwan. They were once part of the Eurasian continent before a large land mass separated from the mainland between 12 and 2 million years ago, and eventually broke apart to form these separate islands.
Varied topography and terrain
The area designated by UNESCO on the four islands covers 427 square kilometers, and the terrain is varied. Amami-Oshima and Tokunoshima are separated by less than 50 kilometers, and have relatively similar topography: rugged broadleaf forest-covered mountains steeply descending to coastal areas marked by ria inlets, white sand beaches, and surrounding reefs. The Yanbaru broadleaf forest covers a large portion of northern Okinawa, while Iriomote hosts Japan’s largest mangrove forest and subtropical jungle. All of the islands are located in the subtropical zone, with an annual average temperature of 21 to 24C, high humidity, and heavy rainfall.
Isolation and endemic species
The location and geological history of these islands have contributed to the development of diverse flora and fauna. The warm waters brought by the Kuroshio current help create a humid climate that supports 1,819 species of vascular plants, 21 kinds of terrestrial mammals, 394 bird species, 36 species of terrestrial reptiles, and 21 species of amphibians. The separation of the islands over many millennia contributed to the evolution of numerous species endemic to each island. Although their combined land area makes up less than 0.5 percent of Japan, the islands are home to 95 globally threatened species, 75 of which are endemic. Of the threatened species, 20 have been identified as Evolutionarily Distinct and Globally Endangered (EDGE) varieties, including the Amami spiny rat, the Ryukyu long-haired rat, and the Amami woodcock. Among the other threatened animals are the Amami rabbit (Amami-Oshima and Tokunoshima), the Okinawa rail (northern Okinawa), and the Iriomote cat, which is only found on Iriomote.
Human factors
Since ancient times, the people of the Ryukyu Islands have lived in a close relationship with their natural surroundings. Their religious and social practices have contributed to protecting the many rare and endemic plants and animals on these islands. The layout of traditional villages is based on a sustainable model, with land use controlled by the community and natural materials, such as coral limestone walls and hedges, used for protection from the elements. Largely isolated, the people of the islands have long survived on what they could secure from the seas and the land nearby, creating tools for each purpose. They passed down various crafts, such as making textiles from natural materials. On the spiritual side, the traditional belief is that gods exist in the mountains of the island and in a paradise beyond the sea’s horizon. The gods are welcomed with annual religious events overseen by priestesses known as noro. These events include festive activities that strengthen a sense of community, such as sumo wrestling, songs, and dances. This Ryukyuan culture, deeply rooted in nature, is still very much a part of daily life.
Caring for the site
Management of the Natural World Heritage Site focuses on promoting sustainable tourism that will minimize the impact on this fragile environment while offering assistance with its maintenance. This includes limiting the number of tourists visiting certain areas, managing the flow of visitors, and requiring the use of certified guides with experience in fieldwork.
