Boronia koniambiensis is a shrub, endemic to the north-western part of Grande Terre in New Caledonia. This species is known from two subpopulations: Koniambo and Katépahié. It is found in shrubland on ultramafic substrates at an altitudinal range of 50-700 m asl. The main threat is presented by ongoing mining activities in Koniambo. The twenty five year projection for mining operations indicates that more than 30% of individuals may be affected. Boronia koniambiensis is assessed as Vulnerable (VU) under criterion A4c with an inferred population reduction of more than 30% over three generations (75 years) starting in 1970 and projected to 2045; and under criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) with the number of threat-defined locations estimated to be six, a continuous decline of all concerned subcriteria and extent of occurrence (EOO) and area of occupancy (AOO) are estimated to be of 96 km².

Geographical area

Boronia koniambiensis is a shrub, endemic to the north-western part of Grande Terre in New Caledonia. This species is known from 2 subpopulations: Koniambo and Katépahié.

Population

Population size is unknown. However, Bocquillonia koniambiensisis is quite common in Koniambo and Katépahié. The twenty five year projection for mining operations indicates that more than 30% of individuals may be affected, and thus contribute to the potential reduction of the total population size.

Habitat

Boronia koniambiensis is found in shrubland on ultramafic substrates at an altitudinal range of 50-700 m asl.

Threats

The main threat is presented by ongoing mining activities in Koniambo. New Caledonia contains 20 - 30% of the world’s nickel resources and has experienced intense mining activities since the late 19th century which has generated soil erosion (1.2% of bare ground mapped by SPOT5 in 2007). Based on the distribution of metal-rich soils and site accessibility, these threats are predictable and planned (there was a rise in nickel production from 60,000 to 200,000 tonnes per year between 2013 and 2015). Koniambo is also under a heightened threat from bushfire and invasive species such as Rusa Deer (Rusa timorensis).

Conservation

Boronia koniambiensis is protected by legislation in Province Nord (under the name Boronella koniamboensis), but does not occur in any protected area. It is noted that KNS has conducted searches and phenologic monitoring since 2015. Germination and propagation tests are ongoing.

Bibliography

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.

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.

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.

Experts

Assessor(s): Tanguy, V., Veillon, J., Amice, R., Barrière, R., Chambrey, C., Fleurot, D., Lannuzel, G.

Reviewer(s): Vandrot, H.

Contributor(s): Wulff, A.

Facilitator(s): Tanguy, V., Chanfreau, S.