Taxonomy

endemique
protegee
UICN

Red List Status -

Vulnerable (VU) , assessed in 12/10/2015

Protected species -

in Northern Province

Xylosma tuberculatum is a narrow endemic shrub found in the northwestern part of Grande Terre in New Caledonia. This species is known from 4 sub-populations : Ouazangou, Koniambo, Paéoua and Boulinda. It is found in shrubland and in high altitude humid forest on ultramafic substrate at an altitudinal range 700-1100 m asl. The main threat is presented by ongoing mining development in Koniambo (KNS) and Ouazangou and past mining development in Paéoua and Boulinda. The twenty five years projection for mining operation indicate that most of individuals will disappear. Its extent of occurrence and area of occupancy are respectively estimated to be of 493 km² and 40 km² while the number of locations are estimated to be 6. Using criteria B and with the estimation of a continuous decline of all all concerned sub-criteria, Xylosma tuberculatum is assessed as Vulnerable B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v).

Geographical area


Xylosma tuberculatum is a narrow endemic shrub found in the northwestern part of Grande Terre in New Caledonia. This species is known from 4 sub-populations : Ouazangou, Koniambo, Paéoua and Boulinda.

Population


Population size is unknown.

Habitat


Xylosma tuberculatum is found in shrubland and in high altitude humid forest on ultramafic substrate at an altitudinal range 700-1100 m asl.

Threats


The main threat is presented by ongoing mining development in Koniambo (KNS) and Ouazangou and past mining development in Paéoua and Boulinda. The twenty five year projection for mining operation indicate that most of individuals will disappear. New Caledonia contains between 20 - 30% of the world’s nickel resources and has experienced intense mining activities since the late 19th century which 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). Boulinda is also under a heightened threat from bushfire. 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).

Conservation


Xylosma genus is protected by legislation in Province Nord, but does not occur in any protected area. It is recommended to collect an herbarium specimen to confirm Koniambo sub-population. This species would benefit from ex-situ and in-situ emergency conservation actions. It is proposed to ensure the follow-up of the known populations and to preserve a viable population on delimited perimeters. It would be moreover advised to realize multiplication tests in order to assist future planting operations.

Bibliography


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

Morat, P.; Jaffré, T.; Tronchet, F.; Munzinger, J.; Pillon, Y.; Veillon, J.-M. and Chalopin, M. 2012. Le référentiel taxonomique Florical et les caractéristiques de la flore vasculaire indigène de la Nouvelle-Calédonie [The taxonomic database « FLORICAL » and characteristics of the indigenous flora of New Caledonia]. Adansonia sér 3(34) , p.177-219.

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

Wulff AS, Hollingsworth PM, Ahrends A, Jaffré T, Veillon J-M, L’Huillier L, et al. 2013. Conservation Priorities in a Biodiversity Hotspot: Analysis of Narrow Endemic Plant Species in New Caledonia.

Experts


Assessor(s): Tanguy, V., Veillon, J., Amice, R., Barrière, R., Chambrey, C., Fleurot, D., Lannuzel, G.

Reviewer(s): Vandrot, H.

Contributor(s): Wulff, A.

Facilitator(s): Tanguy, V., Chanfreau, S.


Geographical distribution