Taxonomy

endemique
protegee
UICN

Synonyms

Calpicarpum seventii (Boiteau) BoiteauNeisosperma sevenetii (Boiteau) Boiteau

Red List Status -

Critically Endangered (CR) , assessed in 10/09/2015

Protected species -

in Northern Province , in Northern Province

Ochrosia sevenetii is a narrow endemic tree found in the northwestern part of Grande Terre in New Caledonia. This species is only known from a single population in Tiébaghi. Neisosperma sevenetii occurs in shrubland and dense humid forest on ultramafic substrate at an altitudinal range 350-400 m asl. The main threat is presented by ongoing mining activities in Tiébaghi area and a twenty five year projection for mining operation indicate that all individuals may be affected in Tiébaghi area. Its extent of occurrence and area of occupancy are equal to 16 km² while the species is known to exist at only a single location. Population size is estimated to be fewer than 250 mature individuals. Ochrosia sevenetii is therefore considered Critically Endangered (CR) according to criteria B1ab(i,ii,iii,v);C2a(ii).

Geographical area


Ochrosia sevenetii is a narrow endemic tree found in the northwestern part of Grande Terre in New Caledonia. This species is only known from a single population in Tiébaghi.

Population


Population size is estimated to be fewer than 250 mature individuals (SLN/IAC study).

Habitat


Ochrosia sevenetii occurs in shrubland and dense humid forest on ultramafic substrate at an altitudinal range 350-400 m asl.

Threats


The main threat is presented by ongoing mining activities in Tiébaghi area. Furthermore, side effects are significant making an irreversible impact on the environment by drying-up entire landscapes and producing dust rising from the ground. The twenty five years projection for mining operation indicate that all 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


Ochrosia sevenetii is protected by legislation in Province Sud and Province Nord, but does not occur in any protected area. It is reported that conservation measures are implemented by SLN (Société le Nickel) through a partnership with IAC (Institut Agronomique néo-Calédonien): Technical guidelines was drawn up in 2015, propagation tests were conducted and planting operations are ongoing (129 individuals were planted in 2015 in Tiébaghi). This species would benefit from ex-situ and in-situ emergency conservation actions. It is proposed to ensure the follow-up of the only known population, to better estimate population size and to preserve a viable population on delimited perimeters on Tiébaghi.

Bibliography


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.

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

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., Fleurot, D., Gailhbaud, P., Garnier, D., Suprin, B.

Reviewer(s): Vandrot, H.

Contributor(s): Wulff, A.

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


Geographical distribution