Melodinus reticulatus is an endemic liana of Grande Terre in New Caledonia. This species is known from two widely-separated massifs: vallée de la Tontouta and Ouazangou. It is found in shrubland on ultramafic substrates at an altitudinal range of 10-400 m asl. The main identified threats are linked to habitat damage by ongoing mining activities and uncontrolled bushfires. Mining extraction projections for the coming 25 years suggest mining could have a significant impact on the species. Therefore, Melodinus reticulatus 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 continuing decline of all concerned subcriteria and extent of occurrence (EOO) and area of occupancy (AOO) are respectively estimated to be of 1,876 km² and 36 km.

Geographical area

Melodinus reticulatus is an endemic liana of Grande Terre in New Caledonia. This species is known from two widely-separated massifs: vallée de la Tontouta and Ouazangou-Taom, which constitutes a disjunct distribution.

Population

Population size is unknown. Mining extraction projections for the coming 25 years could lead to >30% of the population being impacted and thus contribute to the potential reduction of the total population size.

Habitat

Melodinus reticulatus is found in shrubland on an ultramafic substrate at an altitudinal range of 10-400 m asl.

Threats

The main threat is presented by ongoing mining activities in Ouazangou and Tontouta areas. 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). La vallée de Tontouta and Ouazangou-Taom are also under a heightened threat from bushfire and invasive species such as Rusa deer (Rusa timorensis).

Conservation

Melodinus reticulatus is protected by legislation in Province Nord, but does not occur in any protected area. It is recommended to prospect "La vallée de la Tontouta" and it would be moreover advised to develop protected areas on areas of serpentine substrate.

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.

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

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.

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.