Plerandra longistyla is an endemic tree of New Caledonia occurring in shrubland on ultramafic substrate (serpentine). Based on herbarium specimens, it is known from two subpopulations. The habitat of Plerandra longistyla is threatened by mining activities and bushfires. Population size reduction cannot be assessed because of a lack of data. Its extent of occurrence (EOO) is 93 km² and its area of occupancy (AOO) is 12 km². The number of locations, based on mining activities as the main threat, is determined to be two. A continuing decline is projected in its quality of habitat. Using criteria B, Plerandra longistyla qualifies for Endangered [EN B1ab(iii)&2ab(iii)]. Population size is unknown.

Geographical area

Plerandra longistyla is an endemic tree of New Caledonia restricted to the west coast of Grande Terre.

Population

Population size is unknown.

Habitat

Plerandra longistyla is found in shrubland on ultramafic substrate (serpentine).

Threats

Plerandra longistyla may be impacted by mining activities and uncontrolled bushfires. An important threat to biodiversity in New Caledonia comes from past, present and future mining activities. New Caledonia contains 20-30% of the worlds nickel resources. Intense mining activities since the late 19th century has generated soil erosion (1.2% of bare ground mapped by SPOT5 in 2007). Based on the distribution of metal-rich soils and site accessibility, these threats are predictable and planned (rise in nickel production from 60,000 to 200,000 tonnes per year between 2013 and 2015). The two known subpopulations of this species are situated on mining concessions (Ouazangou, Mine Saint-Louis) and could be impacted by direct consequences of the mining of ultramafic soils. Uncontrolled bushfires sweep across New Caledonia each year, especially during the dry season (an average of 20,000 ha of land is burnt each year, with dramatic peaks of 70,000 ha). They contribute to habitat fragmentation and decline in the quality of habitat.

Conservation

Plerandra longistyla is not protected by local legislation and is not situated in any protected areas.It is recommended to survey other ultramafic massifs (Boulinda, Kaala Gomen, Konimabo) where this species could occur and to confirm its presence on Ouazangou.

Bibliography

L'Huillier L.; Jaffré T. and Wulff A. 2010. Mines et Environnement en Nouvelle-Calédonie : les milieux sur substrats ultramafiques et leur restauration.

Lowry, P. P. II; G. M. Plunkett; D. G. Frodin; C. Rodrigues Vaz; M. Gostel and A. N. Nicolas 2016. Revision of Plerandra A. Gray (Araliaceae). III. A taxonomic treatment of Plerandra subg. Dizygotheca..

Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.

Lowry, P. P. II; G. M. Plunkett and D. G. Frodin 2013. Revision of Plerandra A. Gray (Araliaceae). I. A synopsis of the genus with an expanded circumscription and a new infrageneric classification. Brittonia(65) , p.42-61.

Experts

Assessor(s): Tanguy, V.

Reviewer(s): Schatz, G.

Contributor(s): Barrabé, L., Butin, J., Fleurot, D., Vandrot, H., Lowry, P., Barrière, R.

Facilitator(s): Schatz, G.