Syzygium koniamboense is an endemic shrub of the north-western part of Grande Terre in New Caledonia. Its distribution area is discontinuous and it can be found from Boulinda at the base of massif to Koumac. It is is found in shrubland on an ultramafic substrate at an altitudinal range of 5-900 m asl. The main threats are presented by ongoing mining activities in Koniambo, increasing urbanisation between Voh and Koné, and linked to habitat damage by uncontrolled bushfires. In addition this species can be potentially impacted by future mining projetcs at Boulinda. Extraction projections for the coming 25 years could have a significant impact on the population. Syzygium koniamboense 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 seven, a continuous decline of all concerned subcriteria and extent of occurrence (EOO) and area of occupancy (AOO) are respectively estimated to be of 501 km² and 56 km.

Geographical area

Syzygium koniamboense is an endemic shrub of the north-western part of Grande Terre in New Caledonia. Its distribution area is discontinuous and it can be found from Boulinda at the base of massif to Koumac.

Population

Population size is unknown. It seems that this species has a gregarious nature in shrubland and tends to be less dense in transition zone between shrubland and forest. Mmining extraction projections for the coming 25 years could lead to a 30% reduction in the impacted subpopulations and thus contribute to the potential reduction of the total population size.

Habitat

Syzygium koniamboense is found in shrubland on an ultramafic substrate at an altitudinal range of 5-900 m asl.

Threats

The main threats are from ongoing mining activities in Koniambo, increasing urbanization beetween Voh and Koné, and linked to habitat damage by uncontrolled bushfires. 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). Additionally, uncontrolled bushfires sweep across New Caledonia each year, especially during the dry season (an average of 20,000 ha of land is burnt each year, with dramatic peaks of 70,000 ha), and the lowest parts of ultramafic areas are particularly exposed to such risk. The occurrence of Myrtle Rust (Austropuccinia psidii) on New Caledonia may also pose a threat to this species. In addition this species can be potentially impacted by future mining projetcs at Boulinda.

Conservation

Syzygium koniamboense is not protected by legislation in Province Nord and 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. Searches in south Koniambo forest formations and in surrounding massifs (such as Taom) would be advisable.

Bibliography

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.

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

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): Chanfreau, S., Tanguy, V.