Taxonomy
Red List Status -
Critically Endangered (CR) , assessed in 21/04/2017Protected species -
in Southern Province , in Northern Province
Thiollierea rigaultii is an endemic shrub/tree of New Caledonia, known from Avangui and Forêt Français in Grande Terre. It occurs in shrubland on ultramafic substrates at an altitudinal range of 240-400 m asl. The main threats impacting this species come from habitat degradation linked to uncontrolled bushfires and invasive species (Rusa Deer, Rusa timorensis and feral pigs). Its area of occupancy (AOO) and extent of occurrence (EOO) are both equal to 4 km², while the species is known to exist at only a single location. Thiollierea rigaultii is therefore assessed as Critically Endangered (CR) with criteria B1ab(iii,v)+2ab(iii,v) with a continuing decline of all concerned sub-criteria.
Geographical area
Thiollierea rigaultii is an endemic shrub / tree of New Caledonia, known from Avangui and Forêt Français in Grande Terre.
Population
Population size is unknown.
Habitat
Thiollierea rigaultii occurs in shrubland or forest on ultramafic substrate at an altitudinal range of 240-400 m asl.
Threats
The main threats impacting this species come from habitat degradation linked to uncontrolled bushfires and invasive species (Rusa rusa deer (Rusa timorensis) and wild pigs). 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 rigaultii 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. It is moreover recommended to include Avangui area into the current protected-area network.
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.
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.
Barrabé L., Mouly A., Muzinger J. 2011. Deux espèces nouvelles de Thiollierea (Rubiaceae) restreintes aux sols hypermagnésiens du massif du Boulinda (Nouvelle-Calédonie). Adansonia(33) , p.135-148.
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.