Taxonomy

endemique
protegee
UICN

Red List Status -

Endangered (EN) , assessed in 12/10/2015

Protected species -

in Northern Province , in Northern Province

Xylosma inaequinervium is a narrow endemic small tree found in the northwestern part of Grande Terre in New Caledonia. This species is known from 3 massifs : Kopéto, Paéoua and Boulinda. It is found in humid forest and shrubland on an ultramafic substrate at an altitudinal range 800-1,000 m asl. The main threat is presented by ongoing mining development in Kopéto and past mining developpment in Paéoua and Boulinda. The twenty five year projection for mining operation indicate that severals individuals may be affected. Its extent of occurrence (EOO) and area of occupancy (AOO) are respectively estimated to be of 81 km² and 20 km² while the number of locations are estimated to be 3. Xylosma inaequinervium is therefore assessed as Endangered (EN) with criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) with a continuing decline of all concerned sub-criteria.

Geographical area


Xylosma inaequinervium is a narrow endemic small tree found in the northwestern part of Grande Terre in New Caledonia. This species is known from 3 massifs : Kopéto, Paéoua and Boulinda.

Population


Population size is unknown. Although sub-populations are scattered, field surveys emphasise that individuals occurs grouped.

Habitat


Xylosma inaequinervium is found in humid forest and shrubland on an ultramafic substrate at an altitudinal range 800-1,000 m asl.

Threats


The main threat is presented by ongoing mining development in Kopéto and past mining developpment in Paéoua and Boulinda. The twenty five year projection for mining operation indicate that severals individuals may be affected. 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).

Conservation


Xylosma inaequinervium is protected by legislation in Province Nord and Province Sud but does not occur in any protected area. It is noted that KNS has launched prospections and phenologic follow-up since 2015. This species would benefit from ex-situ and in-situ emergency conservation actions. It is proposed to ensure the follow-up of known sub-populations, to preserve a viable population on delimited perimeters on Koniambo. It is proposed to ensure propagation tests in order to assist future planting operations.

Bibliography


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

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

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.

Morat, P.; Jaffré, T.; Tronchet, F.; Munzinger, J.; Pillon, Y.; Veillon, J.-M. and Chalopin, M. 2012. The taxonomic database « FLORICAL » and characteristics of the indigenous flora of New Caledonia. Adansonia(334(2)) , p.177-219.

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): Chanfreau, S., Tanguy, V.


Geographical distribution