Taxonomy

Plerandra nono (Baill.) Lowry, G.M.Plunkett & Frodin
endemique
UICN

Red List Status -

Vulnerable (VU) , assessed in 12/02/2015

Plerandra nono is an endemic tree occurring in dense humid forest on an ultramafic substrate. It is restricted to the massif du Sud in New Caledonia. Some subpopulations (3) are situated on mining concessions. Current or planned exploitation for nickel on the ultramafic massif of the Grand-Sud of New Caledonia will very likely result in a decline in the extent and quality of habitat in the foreseeable future. The other subpopulations are more likely to be impacted by the habitat degradation due to uncontrolled fires and invasive species such as Rusa Deer. Population size reduction cannot be assessed because of a lack of data. With an extent of occurrence (EOO) of 2,650 km², and an area of occupancy (AOO) of 40 km², the estimated number of locations based on the most serious threat of mining is nine. A continuing decline in the extent and quality of habitat is projected. Using criterion B, P. nono qualifies for Vulnerable [VU B1ab(iii)&2ab(iii)]. Population size is unknown.

Geographical area


Plerandra nono is an endemic tree of New Caledonia restricted to the southern half of Grande Terre from Port-Boisé to Sarraméa.

Population


Population size is unknown.

Habitat


Plerandra nono is found in dense humid forest mainly on ultramafic substrates, at an altitudinal range of 0-1,200 m asl.

Threats


An important threat to biodiversity in New Caledonia comes from past, present and future mining activities. New Caledonia contains 20-30% of the world’s nickel resources. Intense mining activities since the late 19th century has generated soil degradation (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 Massif du Sud which hosts Plerandra nono is an actively mined area. Uncontrolled fires sweep across lowlands of 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 can slowly transform dense humid forest on ultramafic soil into shrubland.Anotherthreat comes from the Rusa Deer (Rusa timorensis), which was introduced in the 1880s and adapted extremely well to the Caledonian habitats. Its population may have reached over 100,000 individuals in the wild. This rusa deer (Rusa timorensis) consumes a wide variety of plant species and causes severe damage to trees, which results in very little regeneration.

Conservation


This species occurs in two protected areas (réserve naturelle de la Forêt Nord, réserve naturelle du Mont Mou). Dense humid forests are a patrimonial ecosystem protected by the Code de l'Environnement of Province Sud.

Bibliography


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.

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..

Experts


Assessor(s): Tanguy, V.

Reviewer(s): Schatz, G.

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


Geographical distribution