Austrobuxus clusiaceusis an endemic shrub or small tree of New Caledonia, restricted to the area of Dumbéa, with an extension on Vallée de la Tontouta, in the south of Grande Terre. It is found in shrubland on an ultramafic substrate at an altitudinal range of 50-550 m asl. Its area of occupancy (AOO) and extent of occurrence (EOO) are estimated to be 44 and 127 km², respectively, and it is known from nine locations. The population size is not known but field observations indicate a species locally abundant. Recurrent bushfires and urbanization in Grand Nouméa are suspected to contribute to the degradation of the habitat and population decline but it only affects a very small part of the species' distribution (Dumbéa). New Caledonian official records indicate that forest fires and bushfires destroy, on average, nearly 500 km² per year. And studies have predicted the southern massif has a high risk of wildfire impact (combining fire severenety and vegetation loss) (Mangeas et al. 2019). Overall, though, this species does not seem threatened, but precautionarily, Austrobuxus clusiaceus is assessed as Near Threatened (NT) close to VU B1ab(iii,v)+2ab(iii,v).

Geographical area

Austrobuxus clusiaceus is a shrub or small tree restricted to the area of Dumbéa and Païta on Grande Terre in New Caledonia. This species is present in Dumbéa valley, its presence in Païta nowadays is doubtful.

Population

This species is abundant in Dumbéa valley.

Habitat

It is found in shrubland on an ultramafic substrate at an altitudinal range 50-550 m asl.

Threats

Recurrent bushfires and urbanization in the Grand-Nouméa contribute to the degradation of the habitat. However, this species is abundant and does not seem threatened.

Conservation

Austrobuxus clusiaceus is not legally protected but it occurs in one protected area : réserve naturelle de la Haute-Dumbéa. It is recommended to cultivate in plant nurseries in order to replant it in burnt areas in Dumbéa.

Bibliography

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

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.

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., Cazé, H., Chambrey, C., Dubreuil, M., Fleurot, D., Garnier, D., Lagrange, A., Lannuzel, G., Leborgne, T., Letocart, D., Letocart, I., McCoy, S., Villegente, J.

Reviewer(s): Maura, J.

Contributor(s): Wulff, A.

Facilitator(s): Tanguy, V.