Thiollierea neriifolia is an endemic shrub of New Caledonia, known from Taom in the north of Grande Terre. It occurs in shrubland on ultramafic substrate at an altitudinal range of 300-900 m asl. The main impact identified comes from bushfires and ongoing mining activites: Mine Ouazangou on Taom (NMC). Its extent of occurrence and area of occupancy are both equal to 16 km² while the number of locations are estimated to be four. Thiollierea neriifolia is therefore considered Endangered (EN) according to criteria B1ab(iii,v)+2ab(iii,v) with a continuing decline of habitat quality and numbers of mature individuals.

Geographical area

Thiollierea neriifolia is an endemic shrub of New Caledonia, known from Taom in the north of Grande Terre.

Population

Population size is unknown.

Habitat

Thiollierea neriifolia occurs in shrubland on ultramafic substrate at an altitudinal range of 300-900 m asl.

Threats

The main impact identified comes from bushfires and ongoing mining activites: Mine Ouazangou on Taom (NMC). 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). 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). Lowest parts of ultramafic areas are particularly exposed to such risk.

Conservation

Thiollierea neriifolia is protected by legislation in Province Nord and it does not occur in any protected area. 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. It is recommended to inform the DSCGR (emergency services) on the presence of the species in the concerned areas.

Bibliography

Barrabé L., Mouly A., Lowry II P.P. & Muzinger J. 2011. Reinstatement of the endemic New Caledonian genus Thiollierea Montrouz. (Rubiaceae) necessitated by the polyphyly of Bikkia Reinw. as currently circumscribed. Adansonia(33) , p.115-134.

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

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.

Experts

Assessor(s): Barrabé, L., Amice, R., Bruy, D., Butin, J., Fleurot, D., Garnier, D., Gâteblé, G., Goxe, J., Héquet, V., Lannuzel, G., Suprin, B., Veillon, J.

Reviewer(s): Cazé, H.

Contributor(s): Mouly, A.

Facilitator(s): Tanguy, V., Warimavute, G., Maura, J.