Threats to the Island’s Flora: Alien Species and Theft
The designation of Amami-Oshima as part of a Natural World Heritage Site has brought attention to the problem of alien species of plants, and the need to monitor their spread. Alien species have been introduced to the island for use as roadside greenery or in gardens. Once established, they can compete with and sometimes suppress endemic plant species. Among the worst offenders are the bitter vine (Mikania micrantha), a quickly spreading tropical weed that can produce 40,000 seeds from one stalk, and the lanceleaf tickseed (Coreopsis lanceolata), a flowering plant from North America that is listed among the Ecological Society of Japan’s 100 Worst Invasive Species. Government and non-government organizations are making efforts to raise public awareness of the need to prevent the introduction and spread of such species.
The theft and harvesting of rare and endemic species are another threat to Amami-Oshima’s biodiverse environment. The most fragile plants are often the most frequent targets, leading to an endangered—or worse, extinct—status. Government and non-government organizations are promoting awareness of the severity of this threat, but for now, only an honor system prevents this activity.