Syzygium dawsonianum is an endemic tree or shrub from New Caledonia with a very scattered distribution across Grande Terre. It is known from three subpopulations: Roche Ouaième in the north east, Farino in the center and Thy valley in the south of Grande Terre. It occurs in dense humid forest on non-ultramafic substrates (volcano sedimentary and granite rocks) up to 600 m asl. The main threats identified are bushfires (Ouaième and Thy) and feral pigs (Sus scrofa) and Rusa deer (Rusa timorensis) at Farino causing a degradation of its habitat quality. Its extent of occurrence (EOO) and area of occupancy (AOO) are 1,620 and 36 km², respectively, while the number of locations are equal to three. Therefore, S. dawsonianum is listed as Endangered (EN) under criteria B1ab(iii,v)+B2ab(iii,v).

Geographical area

S. dawsonianum is endemic to New Caledonia where it has a very scattered distribution across Grande Terre. It is known from three subpopulations: Roche Ouaième in the north east, Farino in the center and Thy valley in the south of Grande Terre.

Population

Population size is unknown.

Habitat

S. dawsonianum occurs in dense humid forest on non-ultramafic substrates (volcano sedimentary and granite rocks) up to 600 m asl.

Threats

The main threats identified are bushfires (Ouaième and Thy) and feral pigs (Sus scrofa) and Rusa deer (Rusa timorensis) at Farino causing a degradation of its habitat quality.

Conservation

This species is not protected by legislation in New Caledonia and it does occur in 2 protected areas: Parc des Grandes Fougères, Vallée de la Thy. This species should be included in the regional legislation for a better protection of the species and ex situ and in situ conservation efforts are urgently needed, in particular : ensuring the follow-up of the known subpopulations. The local authority responsible for the coordination of the firefighting effort should be informed about the presence of the species in the concerned areas. Finally it is recommended to improve the knowledge of the species (prospections, more herbarium specimens, specie's ecology) to better understand its distribution and better estimate its status.

Bibliography

Dawson J.W. 1999. Flore de la Nouvelle-Calédonie et dépendances. Volume 23 : Myrtaceae Myrtoideae 1 : Syzygium.

N.Snow,Young S.L. & M.W. Callmander 2016. Syzygium dawsoniana (Myrtaceae): A New Species from New Caledonia with Bullate Leaves. Systematic Botany(41(1)) , p.197-201.

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

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): Héquet, V., Vandrot, H., Barrabé, L., Amice, R., Butin, J., Cazé, H., Fleurot, D., Suprin, B., Chambrey, C., Laudereau, C., Haverkamp, C., Fogliani, B.

Reviewer(s): Gâteblé, G.

Facilitator(s): Warimavute, G., Meyer, S., Tanguy, V.