Araucaria goroensis has a very restricted distribution and habitat. Both the extent of occurrence and area of occupancy are within the thresholds for Endangered and just above those for Critically Endangered. It is known from four locations (sensu IUCN) as all stands and localities are within areas that are or may be threatened by mining and its associated activities. In the recent past (last 50 years) some areas have been impacted by infrastructure development such as road and dam building with a suspected loss of mature individuals. Given its long generation length (c. 400 years) these suspected losses are interpreted as a recent continuing decline under criterion B rather than under criterion A. Its extremely slow growth rate and low fecundity make it particularly susceptible to stochastic events such as an increase in droughts, fires and cyclones.

Geographical area

Restricted to the Goro Plateau and neighbouring areas of Yaté commune in Province Sud, southern New Caledonia.

Population

Population sizes at each site are small to very small (five to usually <50 individuals). About 200 individuals of Araucaria goroensis are known at Le Trou, and a mixed population of 500–1,000 individuals of A. muelleri and A. goroensis at Mamié (Ruhsam et al. 2016)

Habitat

Araucaria goroensis occurs as an emergent in open forest and maquis vegetation (maquis minier) on acidic ultramafic substrates at altitudes of c. 150–550 m. The soil is a lateritic iron-crust oxisol of a type known as cuirasse and the underlying rock type is peridotite. Dominants of the canopy layer include Dacrydium araucarioides Brongn. & Gris (Podocarpaceae) and Gymnostoma deplancheanum (Miq.) L.A.S.Johnson (Casuarinaceae). Other associates include Dracophyllum ramosum Pancher ex Brongn. & Gris and Styphelia pancheri (Brongn. & Gris) F.Muell. (both Ericaceae) and Solmsia calophylla Baill. (Thymelaeaceae) (Wilcox and Platt 2002). The research on seedling recruitment and mortality and stress-tolerator leaf traits in Araucaria ‘muelleri’ by Enright et al. (2009, 2014) was largely based on various study sites on the Goro Plateau, and therefore much of the ecological information in their 2009 paper and most of the results in the 2014 one pertain to A. goroensis, not A. muelleri.

Threats

Araucaria goroensis has a very restricted geographic and edaphic distribution. Growth rates are amongst the slowest recorded and fecundity is low (Enright et al. 2014). None of the currently known subpopulations are within protected areas and most of them occur in areas that are open for mining in the future (Ibanez et al. 2019). In the recent past (the last 40-50 years) some localities have been impacted by infrastructure developments such as road building and dam construction which have led to the loss of mature individuals. In the southern parts of its distribution, fires are rare due to the lack of organic litter and very sparse vegetation. However, in the northern areas, there is a greater risk of fire in stands where the associated vegetation is denser. An increase in fire frequency, coupled with an increase in extreme weather events such as droughts could increase the level of this threat.

Conservation

This species is not protected in province Sud although a few plants are known from a single area which is protected from mining activities (Chutes de la Madeleine). Its slow growth rate and low fecundity make ex situ cultivation difficult and also present problems for its inclusion in restoration projects. This species is monitored and has been propagated via seeds and transplants by the mining operator Vale NC. In-situ and ex situ conservation plantations are being established through Vale NC's Rare species conservation plan: 20 individuals have been planted at the Parc de la Rivière Bleue arboretum and 291 individuals at Wadjana. A study is underway to assess the state of other populations outside of the Goro area and to identifiy suitable stations for future reintroductions (McCoy, comm. pers.)

Bibliography

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.

Wilcox, M. and Platt, G. 2002. Some observations on the flora of New Caledonia. Auckland Botanical Society Journal(57(1)) , p.60-75.

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].

Ruhsam, M., Clark, A., Finger, A., Wulff, A.S., Mill, R.R., Thomas, P., Gardner, M.F., Gaudeul, M., Ennos, R.A. and Hollingsworth, P.M. 2016. Hidden in plain view: cryptic diversity in the emblematic Araucaria of New Caledonia.. American Journal of Botany(103(2)) , p.888-898.

Mill, R.R., Ruhsam, M., Thomas, P.I., Gardner, M.F. and Hollingsworth, P.M. 2017. Araucaria goroensis (Araucariaceae), a new monkey puzzle from New Caledonia, and nomenclatural notes on Araucaria muelleri.. Edinburgh Journal of Botany(74(2)) , p.123-139.

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): Jaffré, T., Gardner, M., Munzinger, J., Thomas, P.

Contributor(s): Butaud, J., Gueugnier, C.

Facilitator(s): Maura, J., Tanguy, V.