Ascension : Ascension Island Conservation Department
Submitted by The Islander (Conservation Office) 08.10.2009 (Article Archived on 22.10.2009)

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.

Marattia purpurascens is the largest of all the endemic species on Ascension. It is found on the weather side of Green Mountain, growing in the open grassland and amongst the bamboo at the summit. Due to it’s size this species is able to compete with other exotic species. Marattia is able to survive in two very differing microclimates. The open grassland is steep and very exposed, whilst the summit is more humid and sheltered from winds and intense sunlight. The survival of this species in both these habitats depends on it’s ability to compete with introduced vegetation and grazing by sheep and rabbits. Successful techniques for propagating M. purpurascens via crown buds have been developed and nursery facilities are currently being expanded to permit larger-scale cultivation.

Sporobolus caespitosus is found on the weather side of Green Mountain, growing in the vertical cliffs where very few other species are present. Populations of this species are found in some extremely inaccessible areas which are very hard to survey. The introduction of exotic grass species are likely to have contributed to the reduction in distribution of S. caespitosus. Erosion of the loose volcanic substrate on the mountain may also pose a threat to the habitats of this species. Restoration work has taken place to increase the numbers of this species in the wild, however, the major management issue is in keeping these areas protected from sheep, and free from invasion, which can be very labour-intensive. A successful protocol for growing this grass from seed has been developed and specimens have been planted near the summit of Green Mountain. These plants, on an open, level soil grow much more vigorously then in wild situations and have started to self-seed.