Asplenium ascensionis

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

Bibliography

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
PLANTAE	POLYPODIOPHYTA	POLYPODIOPSIDA	BLECHNALES	ASPLENIACEAE

Scientific Name:	Asplenium ascensionis
Species Authority:	S.Watson

Assessment Information [top]

Red List Category & Criteria:

Near Threatened ver 3.1

Year Published:

2003

Assessor/s:

Gray, A.

Reviewer/s:

Cronk, Q., Cairns-Wicks, R. (South Atlantic Island Plants Red List Authority) & Jermy, C., Ranker, T. (Pteridophyte Red List Authority)

Justification:
The last assessment (Cronk 1980) listed A. ascensionis as Rare. It should now be considered as Near Threatened using the new IUCN codes. Information comes from literature sources and personal observation. The population is assumed to be stable but no direct measurements have been made of stability. The species could qualify for Vulnerable D2, however, the risk of extinction would appear to be over the very long term rather than the short to medium turn.

History:

1997

–

Rare (Walter and Gillett 1998)

Geographic Range [top]

Range Description:	Known only from the Green Mountain area of Ascension Island, South Atlantic Ocean. Occupies an area less than 1 km², where it is common in areas of remaining suitable habitat.
Countries:	Native: Saint Helena (Ascension)
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population Trend:	Stable

Population Trend:

Stable

Habitat and Ecology [top]

Habitat and Ecology:	Although localised to the Green Mountain area, it can be the dominant species where it occurs. A. ascensionis seems to be able to persist with some introduced vegetation in species poor communities. However, A. ascensionis is no longer found as a component of the ground vegetation and few specimens attain the large size of Hookers collection (Cronk 1980), and has therefore suffered reduction in distribution to some extent. A. ascensionis inhabits stone as well as cinder walls and is found in more sheltered locations that are rarely completely exposed to solar radiation.
Systems:	Terrestrial

Habitat and Ecology:

Although localised to the Green Mountain area, it can be the dominant species where it occurs. A. ascensionis seems to be able to persist with some introduced vegetation in species poor communities. However, A. ascensionis is no longer found as a component of the ground vegetation and few specimens attain the large size of Hookers collection (Cronk 1980), and has therefore suffered reduction in distribution to some extent. A. ascensionis inhabits stone as well as cinder walls and is found in more sheltered locations that are rarely completely exposed to solar radiation.

Systems:

Terrestrial

Threats [top]

Major Threat(s):	A. ascensionis appears to persist well where present, being the dominant species in some areas. Changes in the distribution of A. ascensionis are likely to be over long time-periods. Expansion of the introduced A. capillus-veneris may represent a threat to A. ascensionis, although mutual co-existence may also be conceivable. Long-term monitoring would allow the determination of A. capillus-veneris as a pervasive threat but observations in 2003 indicate that A. capillus-veneris has spread in at least one A. ascensionis area. Volcanic eruptions may also be a possible threat to this species in the future.

Major Threat(s):

A. ascensionis appears to persist well where present, being the dominant species in some areas. Changes in the distribution of A. ascensionis are likely to be over long time-periods. Expansion of the introduced A. capillus-veneris may represent a threat to A. ascensionis, although mutual co-existence may also be conceivable. Long-term monitoring would allow the determination of A. capillus-veneris as a pervasive threat but observations in 2003 indicate that A. capillus-veneris has spread in at least one A. ascensionis area. Volcanic eruptions may also be a possible threat to this species in the future.

Conservation Actions [top]

Conservation Actions:	The population is under surveillance by Ascension Conservation.

Conservation Actions:

The population is under surveillance by Ascension Conservation.

Bibliography [top]

	Ashmole, P. and Ashmole M. 2000. St Helena and Ascension Island: a natural history. Anthony Nelson, Oswestry, UK. Cronk, Q.C.B. 1980. Extinction and survival in the endemic flora of Ascension Island. Biological Conservation 17(3): 207-219. Cronk, Q.C.B. 1992. Relict floras of Atlantic Islands: patterns assessed. Biological Journal of the Linnean Society. 46: 91-103. Cronk, Q.C.B. 1997. Islands: stability, diversity, and conservation. Biological Conservation. 6: 477-493. Cronk, Q.C.B. 2000. The Endemic Flora of St. Helena. Anthony Nelson Publishers, Oswestry, UK. Duffey, E. 1964. The terrestrial ecology of Ascension Island. Journal of Applied Ecology 1: 219-251. Gray, A., Gardner, S., Kirk, L., Robinson, P., Smölka, Z. and Webster, L. 2000. The status and distribution of the endemic vascular flora of Ascension Island. Unpublished Report. IUCN. 2003. 2003 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 18 November 2003. White, R, and George, T. 2002. Status of endemic plants on Ascension Island in 2002. Ascension Conservation Draft Report.

Ashmole, P. and Ashmole M. 2000. St Helena and Ascension Island: a natural history. Anthony Nelson, Oswestry, UK.

Cronk, Q.C.B. 1980. Extinction and survival in the endemic flora of Ascension Island. Biological Conservation 17(3): 207-219.

Cronk, Q.C.B. 1992. Relict floras of Atlantic Islands: patterns assessed. Biological Journal of the Linnean Society. 46: 91-103.

Cronk, Q.C.B. 1997. Islands: stability, diversity, and conservation. Biological Conservation. 6: 477-493.

Cronk, Q.C.B. 2000. The Endemic Flora of St. Helena. Anthony Nelson Publishers, Oswestry, UK.

Duffey, E. 1964. The terrestrial ecology of Ascension Island. Journal of Applied Ecology 1: 219-251.

Gray, A., Gardner, S., Kirk, L., Robinson, P., Smölka, Z. and Webster, L. 2000. The status and distribution of the endemic vascular flora of Ascension Island. Unpublished Report.

IUCN. 2003. 2003 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 18 November 2003.

White, R, and George, T. 2002. Status of endemic plants on Ascension Island in 2002. Ascension Conservation Draft Report.

Citation:	Gray, A. 2003. Asplenium ascensionis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 25 May 2012.
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