Ascension : Ascension Island Conservation Department
Submitted by The Islander (Conservation Office) 24.09.2009 (Article Archived on 08.10.2009)
Saving Ascension’s endemic plants from extinction - These are two of the Ascension’s six endemic plants. All six are all currently on the IUCN Red List of threatened plant species.
This is a database providing information on species that are facing a high risk of global extinction. The Conservation Department is managing a project to propagate these species and increase their numbers in the wild. The aim is to ensure they do not disappear from the Island completely.
Pteris adscensionis is now almost totally confined to two locations the Island, Cricket Valley (460 m) and Breakneck Valley (520 m). The species previously occupied areas on the summit of Green Mountain, however these populations are no longer present. In Cricket Valley the plants are growing amongst Psidium guajava, and in Breakneck Valley they are found in the cracks of cliffs. The climate in these areas is intermediate between the hot, arid lava plains of the lowlands and the cooler, moist conditions on the summit of Green Mountain. Propagation techniques have been successfully developed by Stedson Stroud. Large numbers of P. adscensionis plants have been produced from spores. The plants have been successfully established at the restoration site by Stedson Stroud on Green Mountain. Expansion of this site and trial re-introductions in other locations are necessary to secure sufficient populations for long-term safety. However, this requires a large amount of invasive species clearance and the development of barrier zones around these areas to control weed re-invasion.
Euphorbia origanoides is found on the dry lowlands of Ascension, up to an altitude of 310 m. The distribution of this species is dependent on rainfall, and reductions in it’s distribution can be attributed to dry periods. It has been found that germination, seed set and flowering are triggered by random, unpredictable rainfall events. E. origanoides has been successfully propagated from seed by Stedson Stroud. A high germination rate has been achieved from seed sown at the Green Mountain Nursery. Plants have been transferred to the Chicken Run nursery, where the environmental conditions are comparable to their natural habitats. The objective is to maintain a stock of each population in cultivation, however, this proves difficult because E. origanoides is a short-lived species, and it is not possible to maintain a few plants in cultivation to provide a long-term seed source. The stock must be renewed on a regular basis.
Volunteers welcome. Please contact Stedson Stroud, Ascension Island Conservation Department. Georgetown. Tel: 6359. Email: stedson.stroud@ascension.gov.ac
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