A note on the taxonomy, ecology, distribution and conservation status of the ferns (Pteridophytes) of Rapa Nui (Easter Island)

Abstract

Ferns are an important component of the flora of the remote islands of the Pacific, especially on Rapa Nui (Easter Island), with 16 native species (i.e., 35% of its existing vascular flora) including four island endemics. In this paper, their former and new valid scientific names, their distribution, and abundance are reassessed based on previously published data and recently conducted field surveys (2008-2012). All of the fern species can be considered threatened because of the past and current destruction or modification of their natural habitats, over-grazing by introduced ungulates (horses, cattle, sheep, and goats), fires, and invasive alien plants. Moreover, four species collected in the early 20th century have not been observed since, and might be considered extinct. Habitat restoration projects and conservation plans for the most endangered fern species (including propagation in plant nurseries) should be urgently implemented to conserve the remaining native fern diversity of the island before it is completely lost.