Taxonomy
Red List Status -
Endangered (EN) , assessed in 11/09/2015Protected species -
in Southern Province
Dendrobium polycladium var. atractoglossum is an endemic orchid of New Caledonia known from Kaala-Gomen, Boulinda, Néoua, Kopéto, Négropo, Tchingou and Poum, all located in the north part of Grande Terre (main island). D. polycladium var. atractoglossum occurs in shrubland on ultramafic substrate at an altitudinal range 300-900 m asl. Population is currently not monitored but from experts knowledge, population size is estimated fewer than 2,500 mature individuals. Due to the threats of nickel mining, invasive animals and bushfire, a continuous decline is estimated. Using criteria C, D. polycladium var. atractoglossum qualifies as Endangered (EN) C2a(i).
Geographical area
D. polycladium var. atractoglossum is an endemic orchid of New Caledonia known from Kaala-Gomen, Boulinda, Néoua, Kopéto, Négropo, Tchingou and Poum, all located in north part of Grande Terre (main island).
Population
Population is currently not monitored but based on informations from experts population is estimated to be fewer than 2,500 mature individuals.
Habitat
D. polycladium var. atractoglossum occurs in shrubland on ultramafic substrate at an altitudinal range 300-900 m asl.
Threats
On Kaala, Kopéto, Boulinda,Poum and Canala, nickel mining constitutes the major threat. Elsewhere bushfire and habitat degradation linked to wild pig and rusa rusa deer (Rusa timorensis) (Rusa timorensis) are involved in the continuous decline of D. polycladium var. atractoglossum and its habitat quality.
Conservation
D. polycladium var. atractoglossum is protected by legislation in Province Nord and Province Sud. Due to the high impact of mining activities on D. polycladium var. atractoglossum, it is recommended for sub-population on mining concessions to fence viable population and to work on its propagation in order to elaborate a consistent program of plantation (diversity rate to maintain, number of sub-populations required to protect this species). Then, a monitoring of natural and planted sub-populations should be provided.
Bibliography
Hallé N.; Aubréville A.; Leroy J. F.; 1977. Flore de la Nouvelle-Calédonie et dépendances. Volume 8: Orchidaceae.
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): Butin, J., Laudereau, C., Amice, R., Cazé, H., Fleurot, D., Frayssinet, I., Garnier, D., Goxe, J., Gâteblé, G., Veillon, J., Villegente, J.
Reviewer(s): Tanguy, V.
Contributor(s): Faria, E.
Facilitator(s): Chanfreau, S.