Endemic shrub of New Caledonia, distribution area of Pittosporum oubatchense is discontinuous and found from Ignambi to Dzumac on Grande Terre. This species is restricted to high-altitude dense humid forest on ultramafic substrate and on micaschist, and is found on an altitudinal range 650-1500 m asl. Its area of occupancy and its extent of occurrence are equal to 72km² and 7,166 km² respectively with a total of 16 localities. A continuous decline is projected on the basis of degradations of habitat linked to fire threat, invasive species and mining activities. Using criteria B, P. oubatchense qualifies as Near Threatened (NT) close to (VU) B1ab(iii)+2ab(iii).

Geographical area

Endemic shrub of New Caledonia, distribution area of P. oubatchense is discontinuous and found from Ignambi to Dzumac on Grande Terre.

Population

Population size is not precisely known. The Ningua sub-population is one of the largest sub-populations.

Habitat

This species is restricted to high-altitude dense humid forest on ultramafic substrate and on micaschist, and is found on an altitudinal range 650-1500 m asl.

Threats

P. oubatchense is subject to different types of threats depending of localities. The Ignambi population could be affected by frequent fires recorded on this massif while the population on Aoupinié is threatened by competition with invasive plants. We also notice threats linked to habitat degradation on Ningua due to mining activities, and on Diahoué due to invasive animal species such as rusa deer (Rusa timorensis) and pigs.

Conservation

P. oubatchense is not protected by any legislation, but is known from a large number of protected areas, namely : la réserve naturelle du Mont Humboldt, la réserve de nature sauvage du massif de l’Aoupinié, la réserve naturelle du Pic Ningua, la réserve naturelle de la Nodéla, la réserve naturelle de la forêt de Saille and la réserve intégrale de la Montagne des Sources. Genetic and morphological analysis that include all sub-populations are required to improve our knowledge on this species, as experts on Pittosporum suspect that this species as currently circumscribed consists of two species, with a new species from Tchingou. Finally field surveys are required and should focus Tchingou and Ignambi where P. oubatchense could exist.

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.

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

Tirel, C. & Veillon J.-M. 2002. Flore de la Nouvelle-Calédonie et dépendances. Volume 24 : Pittosporaceae.

Hély-Alleaume 2012. INC : Incendies et biodiversité des éco-systèmes en Nouvelle-Calédonie.

Gomez C.; Mangeas M.; Curt T.; Ibanez T.; Munzinger J.; Dumas P.; Jérémy A.; Despinoy M. and Hély C. 2014. Wildfire risk for main vegetation units in a biodiversity hotspot: modeling approach in New Caledonia, South Pacific. Ecology and Evolution(5) , p.377-390.

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

Experts

Assessor(s): Gemmill, C., Veillon, J., Amice, R., Cazé, H., Dumontet, V., Fleurot, D., Garnier, D., Gâteblé, G., Maggia, L.

Reviewer(s): Tanguy, V.

Facilitator(s): Chanfreau, S.