Pittosporum echinatum is an endemic shrub of New Caledonia whose area of occupancy and extent of occurrence are equal to 44 and 873 km² respectively. P. echinatum occurs in shrubland and undergrowth of humid forest at mid altitude, mostly on volcano-sedimentary substrate and occasionally on ultramafic substrate (Tiébaghi). Population size is not known precisely but could raise around 10,000 mature individuals. Threats to P. echinatum are linked to intensive mining activities for Tiébaghi population, to bushfire for Ouégoa location and finally to damages caused by feral pigs and rusa deer (Rusa timorensis) for Koumac-3 creeks location. All of those threats allow us to project a continuous decline of its area of occurrence, its area of occupancy, habitat quality, number of locations and mature individuals. Using criteria B, P. echinatum is assessed as Vulnerable (VU) under the criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v).

Geographical area

P. echinatum is an endemic species of New Caledonia, distributed on north-eastern Grand Terre with a disruption on massif de Tiébaghi and on "three creeks" station.

Population

Population size is not precisely known, but this species could be greater than 10,000 mature individuals.

Habitat

P. echinatum occurs in shrubland and undergrowth of humid forest at mid altitude, mostly on volcano-sedimentary substrate and occasionally on ultramafic substrate (Tiébaghi).

Threats

The main threats on this species are intensive mining activities for Tiébaghi population, bushfire for Ouégoa locality and thirdly damages caused by rusa deer (Rusa timorensis) and pigs on "Koumac- three creeks" localities. New Caledonia contains between 20 - 30% of the world’s nickel resources. Intense mining activities since the late 19th century have generated soil erosion (1.2% of bare ground mapped by SPOT5 in 2007).

Conservation

P. echinatum is not protected by legislation, but occurs in one protected area : la réserve de nature sauvage du mont Panié. From current phylogenetic studies, different sub-populations should consist of one unique species : P. echinatum. Nevertheless, the presence of one sub-population on ultramafic substrate, whose habitat is clearly different from other sub-populations, would deserve a better assessment of sub-populations variability. Throughout its difference in term of ecological conditions, population from massif de Tiébaghi should be subject to priority conservation measures (fence...).

Bibliography

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.

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.

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

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

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

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., Letocart, I., Letocart, D., Maggia, L., Pain, A.

Reviewer(s): Tanguy, V.

Facilitator(s): Chanfreau, S.