|Scientific Name:||Vateriopsis seychellarum (Dyer ex Baker) F.Heim|
Vateria seychellarum Dyer ex Baker
|Taxonomic Notes:||Vateriopsis seychellarum is the only species in its genus. This genus is endemic to the Seychelles, representing a unique evolutionary lineage of the family of the Dipterocarpaceae. This Family has its main distribution in the Indo-Malaysian area. Vateriopsis is the most western representative of the sub-family of the Dipterocarpoideae isolated in the west of the Indian Ocean (Friedmann 1994).
In majority of classification systems of flowering plants the family of the Dipterocarpaceae belong to the order of the Malvales. In the Cronquist system of classification the Dipterocarpaceae belong to the order of the Theales (Brummitt 1992).
|Red List Category & Criteria:||Critically Endangered B1ab(i,iv); D ver 3.1|
|Assessor(s):||Ismail, S., Huber, M.J. & Mougal, J.|
|Reviewer(s):||Gibbs, D. & Lutz, M.L.|
Vateriopsis seychellarum is endemic to the Seychelles, where is is only known from Mahé. The extent of occurrence (EOO) is 23.3 km2 and it is only known from a total of nine sites. It was historically recorded as one of the co-dominant species of the canopy in low and intermediate forests. It was however nearly cut down to extinction more than 100 years ago because of its valuable timber. There are currently between 37 and 41 mature individuals. The only dispersal mode is gravity and therefore each stand is completely isolated from the other stands. The main threats to this species are intrinsic factors such small population size and limited dispersal. Another main threat is habitat degradation through spreading of alien invasive species. This species should be accorded high priority for conservation efforts as it is the only species of the genus. It is listed as Critically Endangered.
|Previously published Red List assessments:|
|Range Description:||This species is endemic to Mahé, the Seychelles. The EOO was determined to be 23.3 km². It is known from only nine sites. As the known nine stands are all on Mahé, the population is situated in one geographical location. The only dispersal mode is gravity and each stand is completely isolated from the other stands.|
Native:Seychelles (Seychelles (main island group))
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total population size is 58 trees (with a diameter at breast height (1.3 m) more than 10 cm) distributed in nine sites, of which 37-41 are mature individuals. This is the highest number recorded during the past 100 years. The biggest stand, at Riviére Caiman (L’Abondance), consists of 26 mature trees. Seven sites consist of three or less individuals. Two stands do not show any sign of regeneration and four stands lack saplings (> 50cm height) indicating a high mortality of seedlings leading to insufficient regeneration.|
Two out of the 41 mature trees are not in the wild (one grows in a tea plantation and one in a private garden). It is not clear if two individuals at another site ever reproduced because these smaller plants seem to have grown vegetatively from other stems. One group consisting of 17 trees did not show any signs of reproduction and seems to have been planted in the late 1970s.
Historically, this species was recorded as a co-dominant species of the canopy in low and intermediate forests. The main population reduction was most probably more than 100 years ago. This species was already rare in 1899 (Schimper in Diels 1922).
Stand structure data indicates that size classes are missing in every site indicating severe disturbance of regeneration. Although exact stand structure data indicates unhealthy age structure a continuing decline in mature individuals cannot be observed. Natural regeneration occurs at low level; it is questionable if most of the subpopulations are big enough to be viable. There have been several attempts of reintroductions over the past 100 years (e.g., 1911-1914, late 1970s, late 1990s). The low number of known mature individuals indicates that the species is depended on such conservation actions.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Historically recorded as a co-dominant species of the canopy in low and intermediate forests. Seven stands are dominated by introduced species leading to a very low habitat quality. High seedling mortality and dispersal by gravity only.|
|Use and Trade:||The species was nearly cut down to extinction more than 100 years ago because of its valuable timber.|
|Major Threat(s):||The main threats to this species are intrinsic factors such as too small subpopulations to support a viable population and limited dispersal. Another main threat is habitat degradation through spreading of alien invasive species.|
|Conservation Actions:||The species is present in the Morne Seychellois National Park. The most natural stand is outside the national park and not protected. This species should be accorded high priority for conservation efforts as it is the only species of the genus.|
|Citation:||Ismail, S., Huber, M.J. & Mougal, J. 2011. Vateriopsis seychellarum. The IUCN Red List of Threatened Species 2011: e.T33549A9792189.Downloaded on 24 September 2017.|