Rare and endemic vascular plants of the Pitcairn Islands, south-central Pacific Ocean: A conservation appraisal

Abstract

The endemic and threatened plants of the Pitcairn Islands (Pitcairn, Henderson, Oeno, Ducie) are listed and their conservation status assessed. The volcanic Pitcairn and the raised atoll Henderson are the most floristically rich of the islands, and each has a number of endemic taxa. Over half of the native Pitcairn flora is either threatened or insufficiently known (but likely to be threatened), the main threats being removal of native vegetation cover and the invasion of exotic taxa, particularly Syzygium jambos. A detailed survey of the Pitcairn flora is urgently needed to determine fully the status, likely threats, and measures required to conserve the native flora. Ex situ conservation of the endangered Pitcairn taxa and protection of suitable remaining habitats are the most urgent conservation requirements in the whole of the island group. Less than 20% of the Henderson taxa are threatened, and only two of the endemic taxa ( Myrsine hosakae and Santalum insulare var. hendersonensis) are considered threatened. Threatened taxa on Henderson are mostly species which occur very locally on the island or in small populations; they include several very widespread species. Oeno and Ducie are atolls with depauperate floras; Oeno contains three threatened taxa, one of which may be a recent colonist, and another may be extinct. We recommend an immediate floristic survey of Pitcairn, the establishment of a Conservation Officer and the implementation of a sustainable development and conservation policy for the island.