Ecosystem red listing and identification of Mursala Island as the first important plant area in Indonesia

Important plant area (IPA) is one of the global approaches to conserving threatened species and their habitats in situ. In the present study, we assess the risk of ecosystem collapse of Mursala Island and identify the island’s potential as the first IPA site in Indonesia. Mursala Island is located on the west coast of the Sumatera Utara Province and is known as one of the hotspots for dipterocarps species diversity. Our compiled data records at least 178 species of plant on Mursala Island, which belong to 47 families. A total of 104 species have been assessed for their conservation status according to the IUCN Red List, of which 27 (25.96%) are threatened with extinction with the category of Critically Endangered (CR; 4), Endangered (10), and Vulnerable (13). The majority (24 or more than 88%) of these threatened species are from the Family Dipterocarpaceae. Following the IUCN Red List of Ecosystems protocol, we propose CR B1c as the risk category of Mursala Island’s ecosystem. Under this category, the ecosystem is considered to be at an extremely high risk of collapse. Furthermore, our assessment shows that Mursala Island qualifies as an IPA under criteria Ai and Aii. Increasing the protection level of the island is recommended to conserve the ecosystem and its plant diversity.