Taxonomy
Red List Status -
Endangered (EN) , assessed in 08/09/2017
Oxera microcalyx
©Jean-Jacques Villegente - Feuillage, inflorescence - Sentier du Dogny. Alt. 400 m.
Oxera microcalyx is a shrub endemic to New Caledonia, restricted to the center of Grande Terre, on Plateau de Dogny and Ouipoin. It occurs in forest undergrowth on volcano-sedimentary between 260 and 900 m asl. It is known from a two locations and its area of occupancy (AOO) and extent of occurrence (EOO) are respectively equal to 12 and 15 km². The main threats are feral pigs (Sus scrofa) and rusa deer (Rusa timorensis) that cause habitat degradation. Deer also harm mature individuals by scratching or destroying the stems. Therefore, O. microcalyx is listed as Endangered (EN) under criteria B1ab (iii,v)+2ab(iii,v) with an estimated reduction of the concerned sub-criteria.
Geographical area
O. microcalyx is endemic to New Caledonia where it is restricted to the center of Grande Terre. It has two subpopulations at Plateau de Dogny and Ouipoin.
Population
Population size is unknown but the species seems to be locally abundant. However, no regeneration was observed.
Habitat
O. microcalyx occurs in forest undergrowth on volcano-sedimentary substrate between 260 and 900 m asl.
Threats
The main threats are bushfires and invasive species, namely feral pigs (Sus scrofa) and Rusa deer (Rusa timorensis). Both impact habitat quality, but deer also harm mature individuals by scratching or destroying the stems.
Conservation
This species is not protected by any legislation and it doesn't occur in any protected areas. This species is cultivated at the IAC (Institut Agronomique de Nouvelle-Calédonie) nursery of Saint-Louis with only a few number of individuals. Therefore more ex situ and in situ emergency conservation actions (monitor known populations and to preserve a viable one in delimited sites, where invasive species are under control) should be needed to better protect this species. It is also recommended to inform the local authority responsible for the coordination of the firefighting effort about the presence of the species in the concerned areas. Moreover a protected area should be etablished in Plateau de Dogny area.
Bibliography
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.
Gâteblé G. and Munzinger J. 2011. Réhabilitation d'Oxera pancheri Dubard (Lamiaceae), espèce menacée de la Nouvelle-Calédonie. Adansonia(34 (2)) , p.377-388.
Barrabé L, Karnadi-Abdelkader,G, Ounemoa,J,de Kok RPJ., Robert N, Gâteble,G. 2015. Recircumscription of Oxera (Lamiaceae: Ajugoideae) ta include Faradaya based on molecular and anatomical data. Botanical Journal of the Linnean Society(179) , p.693-711.
Gâteblé, G. 2016. Flore ornementale de Nouvelle-Calédonie.
Mabberley DJ, de Kok RPJ. 2004. Labiatae. In: Morat P,ed. Flore de la Nouvelle-Calédonie et dépendance.
Experts
Assessor(s): Gâteblé, G., Barrabé, L., Fleurot, D., Amice, R., Cazé, H., Bruy, D., Héquet, V., Vandrot, H., Butin, J., Mandaoué, L., Haverkamp, C., Dumontet, V., Laudereau, C.
Reviewer(s): Meyer, S.
Facilitator(s): Tanguy, V., Warimavute, G.