Taxonomy
Red List Status -
Critically Endangered (CR) , assessed in 03/07/2017Protected species -
in Southern Province , in Northern Province
The extremely small extent of occurrence (36 km²) and single location, coupled with a very small population size (less than 1,000 plants), lack of regeneration as well as recent and projected continuing decline, qualify this species for listing as Critically Endangered.
Geographical area
Confined to a small area around Rivière des Lacs, Lac en Huit, Lac Intermédaire and Grand Lacs in southern New Caledonia. Occurs at 150 to 275 m asl. In the past it was probably more widespread but has declined due to fires, inundation from reservoirs and hybridisation with Dacrydium araucarioides.
Population
A rare species with a total population of less than 1,000 trees.
Habitat
A rheophyte growing along the edges of streams in association with Retrophyllum minus, Neocallitropsis pancheri and a range of other flowering plants. It possesses an unusual root anatomy that allows it to withstand high levels of inundation (Carlquist and Nazaire 2016).
Threats
The main ongoing threat is fire. In the recent past several subpopulations were lost due to the construction of a dam. At the Chute de Madeleine Reserve, some degradation of its main habitat occurred due to increasing numbers of visitors. A new management plan has reduced their impact. The construction of a new hydro-metallurgical facility 10 km upstream may lead to pollution and water stress because of the extraction of minerals. Hybrids with Dacrydium araucarioides have been reported and described (Knopf et al. 2007). This species has become more common in the areas where D. guillaminii occurs.
Conservation
This species is legally protected by province Sud and province Nord. One of the largest subpopulation occurs in a protected area (réserve of Chutes de la Madeleine) which is vulnerable to fires. Protecting the wetlands of plaine des Lacs recently recognized by RAMSAR through a management plan would be beneficial to this species. This species is monitored and multiplicated by the mining operator Vale NC (Rares species conservation plan) . Monitoring is needed for existing populations and regeneration. It is also necessary to undertake ex-situ studies to know how to produce seeds and cultivate plants for future restoration work if it is required.
Bibliography
Jaffré, T., Munzinger, J. & Lowry, P.P. 2010. Threats to the conifer species found on New Caledonia’s ultramafic massifs and proposals for urgently needed measures to improve their protection.. Biodiversity and Conservation (19) , p.1485-1502.
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
Jaffré, T., Bouchet, P. and Veillon, J.-M. 1996. Threatened plants of New Caledonia: Is the system of protected areas adequate?. Biodiversity and Conservation (7(1)) , p.109-135.
de Laubenfels, D.J. 1972. Flore de la Nouvelle-Calédonie et dépendances..
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.
Munzinger J., Morat Ph., Jaffré T., Gâteblé G., Pillon Y., Rouhan G., Bruy, D., Veillon J.-M., & M. Chalopin 2020. FLORICAL: Checklist of the vascular indigenous flora of New Caledonia [continuously updated].
Knopf, P., Nimsch, H. and Stutzel, T. 2007. Dacrydium x suprinii nov. hybr., a hybrid of Dacrydium araucarioides Brongn. et Griseb. and Dacrydium guillauminii Buchh.. Feddes Repertorium(118(1-2)) , p.51-59.
Carlquist, S, and Nazaire, M. 2016. SEM studies of two riparian New-Caledonian conifers reveal air channels in stem wood; field observations.. Aliso(34(1)) , p.1-7.
Cornu, A., Sarrailh, J.-M. and Marion, F. 2001. Espèces endémiques et restauration écologique en Nouvelle-Calédonie.. Bois et Forêts des Tropique(268(2)) , p.57-68.
Experts
Assessor(s): Amice, R., Cazé, H., Dumontet, V., Fleurot, D., Garnier, D., Héquet, V., Lagrange, A., Lannuzel, G., McCoy, S., Suprin, B., Veillon, J.
Reviewer(s): Gardner, M., Munzinger, J., Jaffré, T., Thomas, P.
Contributor(s): Gueugnier, C., Butaud, J.
Facilitator(s): Tanguy, V., Maura, J.