Oxalis balansae is an endemic monocaulous shrub from New Caledonia restricted to the northwestern part of Grande Terre. This species is known from two subpopulations: Poum massif and Boulinda massif. It is found in scrubland on ultramafic substrate up to 500 m asl. The main threat is presented by ongoing mining development in Poum. In addition this species could be potentially threatened by future mining development at Paéoua and in the past it has been affected by bushfires on the Paéoua plateau (personal communication Veillon, J.-M.). Its area of occupation (AOO) and extent of occurrence (EOO) are estimated to 28 km² and 277 km², while the number of locations are estimated to be four. Therefore Oxalis balansae is assessed as Endangered (EN) under criteria B1ab(i,ii,iii,v)+2ab(i,ii,iii,v) with an estimated continuing decline of all the concerned sub-criteria.

Geographical area

Oxalis balansae is endemic to New Caledonia where it is restricted to the northwestern part of Grande Terre. This species is known from two subpopulations: Poum massif and Boulinda massif.

Population

The population size is not known.

Habitat

This species grows in scrubland on ultramafic substrate up to 500 m asl.

Threats

The main threat is presented by ongoing mining development in Poum. In addition this species can be potentially threatened by future mining development at Paéoua and in the past it has been affected by bushfires at Paéoua plateau (personal communication Veillon, J.-M.).

Conservation

Oxalis balansae is protected by legislation in Province Nord, but does not occur in any protected areas. It is recommended to conduct searches at Koniambo and, if possible, to collect a herbarium specimen to confirm the presence of the species there. This species would benefit from ex situ and in situ emergency conservation actions. It is proposed to monitor known subpopulations. Moreover, it is suggested to raise awareness on this species amongst local stakeholders as well as information of the DSCGR (government department overseeing firefighting actions) on the presence of the species in the concerned areas.

Bibliography

Munzinger J., Morat Ph., Jaffré T., Gâteblé G., Pillon Y., Rouhan G., Bruy, D., Veillon J.-M., & M. Chalopin 2020. FLORICAL: Checklist of the vascular indigenous flora of New Caledonia [continuously updated].

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.

Experts

Assessor(s): Amice, R., Barrière, R., Bruy, D., Cazé, H., Fleurot, D., Lagrange, A., Lannuzel, G., Laudereau, C., Mandaoué, L., Vandrot, H.

Reviewer(s): Meyer, S.

Facilitator(s): Fourdrain, A., Warimavute, G.