Rescue, ecology and conservation of a rediscovered island endemic fern (Anogramma ascensionis):ex situmethodologies and a road map for species reintroduction and habitat restoration

Abstract

Last seen in 1958, the Ascension Island endemic fern, Anogramma ascensionis, was listed as extinct on the 2003 IUCN Red List. However, a 2009 survey rediscovered four plants on Green Mountain. Spores were collected and cultured in vitro at the Royal Botanic Gardens, Kew, where a living collection of thousands of gametophytes and hundreds of sporophytes has been developed. To gain further insights into the biology of this species and the potential implications of in vitro multiplication for conservation purposes, samples were characterized from the karyological point of view. Chromosome analysis of root tips has confirmed that the species is tetraploid, and flow cytometry assessments have revealed that haploid gametophytes produce diploid sporophytes, which confirms natural fertilization. In addition, an rbcL sequence from A. ascensionis has been generated and compared with those published for other Anogramma spp., suggesting a close relationship with A. chaerophylla from Brazil. Further surveys of Green Mountain have reported the presence of 40 A. ascensionis sporophytes in total. Vegetation community analyses have suggested that the present population may be confined to suboptimal habitats. We therefore propose that, prior to the dramatic transformation of the vegetation on the island as a result of the invasion of alien species (particularly Adiantum spp.), A. ascensionis may have flourished in more humid and shaded parts of the mountain. A multidisciplinary approach involving in vitro culture, invasive species clearance and controlled translocation is discussed as the future roadmap for the conservation of this critically endangered fern. Our experiences have also highlighted lessons more broadly applicable to the conservation of extremely rare species elsewhere in the world, especially on remote island systems. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174, 461–477.

Current knowledge, status, and future for plant and fungal diversity in Great Britain and the UK Overseas Territories

“…Many territories are growing threatened species for reintroduction programmes, e.g., in Turks and Caicos Islands Pinus caribaea var. bahamensis (Sanchez et al, 2019), and on Ascension including Anogramma ascensionis (Baker et al, 2014).…”

“…Species range extensions are regularly recorded, e.g., in the British Virgin Islands (Bárrios, Sustache, Goyder, & Hamilton, 2020; BVI TIPAs National Team, 2019). Endemic plants thought extinct have been found again, e.g., Anogramma ascensionis (Ascension; Baker et al., 2014; Gray et al., 2005), Abutilon pitcairnense (Pitcairn; Smyth et al., 2010), and Mellissia begoniifolia (St Helena; Fay, Thomas, & Knapp, 2007).…”

Prediction of Suitable Habitat for Lycophytes and Ferns in Northeast China: A Case Study on Athyrium brevifrons

“…Bruni et al (2013) evaluated the extinction risk for the aquatic fern Marsilea quadrifolia, indicated active conservation strategies (such as relocation and reintroduction) needing to be implemented to improve the survival rate thereof. To a species on the edge of extinction such as island endemic fern Anogramma ascensionis, Baker et al (2014) proposed rehabilitation of areas suitable for reintroduction as an important step in an integrated conservation plan, and invasive species will be eradicated from potential sites as part of the preparatory work, therefore, the research on suitable habitats is prerequisite for the effective conservation and utilisation of lycophyte and fern species.…”

Desarrollo del gametofito y conservación de Ctenitis submarginalis (Dryopteridaceae) en la provincia de Buenos Aires, Argentina.

“…In-vitro spore germination is a reliable method for the propagation of ferns, and this procedure is being carried out widely, often in conjunction with cryopreservation, for the conservation of many species (Baker et al, 2014). The knowledge of the ferns reproductive biology and appropriate methods for propagation, planting out and survival of the individuals are essential for a conservation program.…”