Taxonomy
Synonyms
Cupheanthus microphyllus GuillauminRed List Status -
Endangered (EN) , assessed in 29/02/2016Protected species -
in Southern Province
Syzygium virotii is an endemic shrub restricted to Tontouta basin on Grande Terre in New Caledonia. It is found in open shrubland on an ultramafic substrate at an altitudinal range 100-950 m asl. Recurrent bushfires and past and on-going mining activities in the Tontouta valley contribute to the degradation of the habitat. One subpopulation is directly impacted by the mine Gallieni/Vulcain. Myrtle's rust is a potential supplementary threat. Its extent of occurrence (EOO) and area of occupancy (AOO) are respectively estimated to be of 62 and 32 km² with an estimation of five locations (Gallieni, Kalouehola, Humboldt, Mont Tonta, Vallée Tontouta). Syzygium tontoutaense is therefore assessed as Endangered (EN) with criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) with a continuing decline of EOO, AOO, habitat quality, number of sub-population and number of mature individuals.
Geographical area
Syzygium virotii is an endemic shrub restricted to Tontouta basin on Grande Terre in New Caledonia.
Population
Not common, this species is found as scattered individuals.
Habitat
It is found in open shrubland on an ultramafic substrate at an altitudinal range 100-950 m asl.
Threats
Recurrent bushfires and on-going (and past) mining activities (Tomo, Vulcain, and Opoué) contribute to the degradation of the habitat, especially to erosion. Some individuals are directly impacted by the Gallieni/Vulcain mine and uncontrolled fires sweep across lowlands of New Caledonia each year, especially during the dry season (an average of 20,000 ha of land is burnt each year). New Caledonia contains 20-30% of the world’s nickel resources. Intense mining activities since the late 19th century 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 (rise in nickel production from 60,000 to 200,000 tonnes per year between 2013 and 2015). This species could also be impacted by Myrtle Rust (Austropuccinia psidii), which was declared in 2013 in New Caledonia. It seems the rust has a predilection for riverbank species.
Conservation
Syzygium virotii is protected by legislation in Province Sud. It occurs in one protected area : réserve naturelle du Mont Humboldt. This species would benefit from emergency in-situ and ex-situ conservation measures. Monitoring is needed of the existing populations and regeneration. It seems this species is recalcitrant to seed banking. In terms of protection, it is recommended to preserve a viable population within a delimited perimeter on the Gallieni/Vulcain mine. While it seems difficult to propose perennial measures as long as the valley will be exploited, it is proposed to protect some areas of the valley of Tontouta. It is moreover recommended to gather mining actors to get an inventory of protection measures already implemented and to try to launch a collaboration between institutions (DIMENC and DENV) and mining operators (SLN, Ballande, SMGM) in order to preserve the Tontouta flora.
Bibliography
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.
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.
L'Huillier L.; Jaffré T. and Wulff A. 2010. Mines et Environnement en Nouvelle-Calédonie : les milieux sur substrats ultramafiques et leur restauration.
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
Experts
Assessor(s): Tanguy, V., Veillon, J., Amice, R., Cazé, H., Chambrey, C., Dubreuil, M., Fleurot, D., Garnier, D., Lagrange, A., Lannuzel, G., Leborgne, T., Letocart, D., Letocart, I., McCoy, S., Villegente, J.
Reviewer(s): Maura, J.
Contributor(s): Wulff, A.
Facilitator(s): Tanguy, V.