Taxonomy

endemique
protegee
UICN

Synonyms

Podonephelium balansae Guillaumin

Red List Status -

Critically Endangered (CR) , assessed in 11/12/2014

Protected species -

in Northern Province , in Northern Province

Podonephelium parvifolium is an endemic tree of New Caledonia occurring in sclerophyllous forest. This species has suffered from dry forest reduction and fragmentation. This is particularly linked to agriculture on the west coast. Today's main threat for Podonephelium parvifolium comes from habitat degradation due to Rusa Deer (Rusa Timorensis) and uncontrolled fires. Its area of occupancy is estimated to be 8 km² as well as its extent of occurrence. The number of locations, based upon Rusa Deer as the main threat, is estimated to be one (Koumac). If the subpopulation of Bourail was to be rediscovered, Podonephelium parvifolium would be in a situation of severe fragmentation.A continuing decline has been observed in its extent of occurrence, area of occupancy, quality of habitat, number of subpopulations and number of mature individuals. Using criteria B, P. parvifolium is assigned a status of Critically Endangered B1ab(i,ii,iii,iv,v)&2ab(i,ii,iii,iv,v). The population size is estimated to be fewer than 50. Under criteria D, P. parvifolium is Critically Endangered.

Geographical area


Podonephelium parvifolium is an endemic tree of New Caledonia restricted to the west coast of Grande Terre.

Population


Until recently, the last known collection of Podonephelium parvifolium was made in 1972, but intensive efforts to re-locate this species were successful in 2011 with the discovery, by Jean-Pierre Butin, of a small population of nine individuals in a tiny remnant patch of natural vegetation in Koumac. The subpopulation of Bourail has not been documented for more than 140 years and efforts to relocate it were not successful. The subpopulation in Koumac shows no seedlings or juvenile individuals (the smallest observed was 2 cm in diameter).The number of mature individuals is estimated to be fewer than 50 (Jean-Pierre Butin's observation in Koumac).

Habitat


Podonephelium parvifolium grows in remnant dry forest on calcareous substrates at low elevation (100-250 m). Sclerophyllous forests in New Caledonia are the most heavily impacted native vegetation type in New Caledonia, of which only 1–2% of the original cover remained as of the mid-1990s (Bouchet et al. 1995) and even less today. Because of their propensity to become pastures and their susceptibility to fire, dry forests have reduced dramatically, in size as well as in quality. In New Caledonia, they have been extensively cleared for agricultural purposes for a century; what remains today are highly fragmented patches.

Threats


Tropical dry forests are probably among the world's most endangered of all lowland tropical forests. Because of their propensity to become pastures and their susceptibility to fire, dry forests have reduced dramatically, in size as well as in quality. In New Caledonia, they've been extensively cleared for agricultural purposes or urbanization for a century; what remains today are highly fragmented patches that have been estimated at 2% of the original area.Today's main threat to Podonephelium parvifolium comes from Rusa Deer (Rusa timorensis), which was introduced in the 1880s and adapted extremely well to Caledonian habitats. Its population may have reached over 100,000 individuals in the wild. This rusa deer (Rusa timorensis) consumes a wide variety of plant species and causes severe damage to trees and very little regeneration. Uncontrolled fires sweep across lowlands of New Caledonia each year, especially during the dry season (an average of 20,000 ha of land is burnt each year, with dramatic peaks of 70,000 ha). They have slowly transformed remnant patches of dry forest into shrubland dominated by Acacia spirorbis and Leucaena leucocephala.

Conservation


Podonephelium parvifolium is protected by local legislation (Code de l'environnement de la Province Nord) but it does not occur in any protected areas while dry forests benefit from a conservation programme managed by the Conservatoire des Espaces Naturels.Dry forests are a patrimonial ecosystem protected by the Code de l'Environnement of the Province Sud.This species would benefit from in-situ and ex-situ emergency conservation actions. It is moreover recommended to survey Bourail surroundings again.

Bibliography


Munzinger J. et al. 2013. A Taxonomic Revision of the Endemic New Caledonian Genus Podonephelium Baill. (Sapindaceae). Systematic botany(38) , p.1105-1124.

Bouchet, P.; Jaffré, T. and Veillon J.-M. 1995. Plant extinction in New Caledonia: protection of sclerophyll forest urgently needed. Biodiversity and Conservation(4) , p.415-428.

de Garine-Wichatitsky, M.; Soubeyran, Y.; Maillard, D. and Duncan, P. 2005. The diets of introduced rusa deer (Cervus timorensis russa) in a native sclerophyll forest and a native rainforest of New Caledonia. New Zealand Journal of Zoology(32) , p.117-126.

Experts


Assessor(s): Tanguy, V.

Reviewer(s): Schatz, G.

Contributor(s): Lowry, P., Gâteblé, G., Garnier, D., Fleurot, D., Isnard, S., Anquez, M., Barrabé, L., Amice, R., Cazé, H., Birnbaum, P., Vandrot, H., Munzinger, J., Butin, J.

Facilitator(s): Schatz, G.


Geographical distribution