Taxonomy
Arillastrum gummiferum
Common name :
Chêne gomme, kii (xârâcùù), touin (drubéa)
Synonyms
Spermolepis gummifera Brongn. & Gris • Spermolepis rubra Vieill. ex Guillaumin
Myrtomera gummifera (Brongn. & Gris) Stone
Red List Status -
Vulnerable (VU) , assessed in 17/11/2017
Arillastrum gummiferum, a eucalypt locally known as "chêne gomme", is an endemic tree from New Caledonia, where it is now restricted to the south and part of the east coast of Grande Terre. It is found in dense humid forest and shrubland on ultramafic substrate, up to 500 m asl. Its extent of occurrence (EOO) and area of occupancy (AOO) are estimated at 4,831 and 184 km², respectively. This species has been heavily logged in the past and its timber used for construction. Past overexploitation has led to major habitat degradation, severe fragmentation of its populations, as well as significant declines of the number of individuals, EOO and AOO. Some subpopulations (Tiébaghi in the northwest, Port Boisé in the far south) have entirely disappeared. Although this threat is no longer ongoing, it is estimated that 30% of the population has been lost to logging since the 1860s (three generations is longer than 160 years). Therefore, Arillastrum gummiferum is listed as Vulnerable (VU) under criterion A2cd.
Geographical area
A. gummiferum is endemic to New Caledonia, where it is restricted to the south of Grande Terre. It is also present along the east coast up to Houaïlou.
Population
Population size is unknown, but field observations indicate that the species is not very common.
Habitat
A. gummiferum occurs in dense humid forest and shrubland on ultramafic substrate, up to 500 m asl.
Threats
The species has a history of intensive logging for its timber, which has caused significant population reduction (Heckel 1892) and fragmentation since the 19th century (Richer de Forges & Pascal 2008). Although plantations have been made, illegal logging is still a problem. Recurrent bushfires and mining activities (Nakéty (SMT), Kouaoua (SLN), Goro (Vale)) constitute other serious threats to this species, causing habitat degradation.
Conservation
A. gummiferum is not protected by any legislation in New Caledonia, but it occurs in at least three protected areas (Rivière Bleue, Barrage de Yaté, Pic du grand Kaori), probably more (Bois du Sud, Forêt Cachée, Forêt Nord). This species should be included in the local legislation in order to better control its exploitation and use. Besides, myrtle rust (Austropuccinia psidii) infections have been observed ex situ, so monitoring should occur in the wild in that regard.
Bibliography
Soewarto J., Carriconde F., Hugot N., Bocs S., Hamelin C. & Maggia L. 2018. Impact of Austropuccinia psidii in New Caledonia, a biodiversity hotspot.
Richer de Forges, B. & Pascal, M. 2008. La Nouvelle-Calédonie, un « point chaud » de la biodiversité mondiale gravement menacé par l’exploitation minière.
Dawson J.W. 1992. Flore de la Nouvelle-Calédonie et dépendances. Volume 18 : Myrtacées Leptospermoïdées.
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
Experts
Assessor(s): Amice, R., Butin, J., Fleurot, D., Garnier, D., Goxe, J., Héquet, V., Lannuzel, G., Suprin, B., Veillon, J.
Reviewer(s): Vandrot, H.
Facilitator(s): Tanguy, V., Warimavute, G.