Psychotria oua-tilouensis is an endemic shrub of New Caledonia, known recently from four sub-populations : Taom, Oua Tilou, Voh, Farino / Sarraméa in Grande Terre. Old herbarium specimens were collected at Houaïlou : presqu île de Bâ (1969) to embouchure du Dotio (1872) but recent prospecting efforts failed to rediscover it on the eastern part of Grande Terre. It in dense humid forest, shrubland or heavily degraded former forest on ultramafic substrate at an altitudinal range 0- 1,200 m asl. The main impact identified comes from past and on-going mining activites. Past mining activities may have lead to a drastic reduction in the population of the eastern part of Grande Terre. Its area of occupancy (AOO) and extent of occurrence (EOO) being respectively estimated to 36 and 1,877 km², while the number of locations are estimated to be four. Psychotria oua-tilouensis 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

Psychotria oua-tilouensis is an endemic shrub of New Caledonia, known recently from four sub-populations : Taom, Oua Tilou, Voh, Farino / Sarraméa in Grande Terre. Old herbarium specimens were collected at Houaïlou : presqu île de Bâ (1969) to embouchure du Dotio (1872) but recent prospecting efforts failed to rediscover it on the eastern part of Grande Terre.

Population

It is known from four sub-populations: Taom, Oua Tilou, Voh and Farino / Sarraméa.

Habitat

Psychotria oua-tilouensis occurs in dense humid forest, shrubland or heavily degraded former forest on ultramafic substrate at an altitudinal range 0- 1,200 m asl.

Threats

Main identified threats is linked to past mining activities: Houaïlou : presqu île de Bâ, Nakéty, embouchure du Dotio; and on-going mining activities: Ouazangou (NMC).

Conservation

Psychotria oua-tilouensis is unprotected by legislation but it occurs in oine protected area : Mont Do. 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 the mining area. Prospection in eastern part of Grande Terre are urgently needed to confirm the presence of the species.

Bibliography

Barrabé L. 2013. Systématique et Evolution du genre Psychotria (Rubiaceæ) en Nouvelle-Calédonie.

Barrabé L, Maggia L, Pillon Y, Rigault F, Mouly A, Davis AP, Buerki S 2014. New Caledonian lineages of Psychotria (Rubiaceae) reveal different evolutionary histories and the largest documented plant radiation for the archipelago. Molecular Phylogenetics and Evolution(71) , p.15-35.

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., Cazé, H., Dumontet, V., Fleurot, D., Garnier, D., Gâteblé, G., Hequet, V., Maura, J., McCoy, S., Suprin, B., Vandrot, H., Veillon, J.

Reviewer(s): Lannuzel, G., Tanguy, V.

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