Taxonomy

Podonephelium davidsonii Munzinger, Lowry, Callm. & Buerki
endemique
protegee
UICN

Red List Status -

Endangered (EN) , assessed in 12/02/2015

Protected species -

in Northern Province

Podonephelium davidsonii is an endemic tree of New Caledonia occurring in sclerophyllous forest. This species has suffered dry forest reduction and fragmentation. This is particularly linked to agriculture on the west coast. Today's main threat for Podonephelium davidsonii comes from habitat degradation due to Rusa Deer (Rusa timorensis) and uncontrolled fires. Its area of occupancy is estimated to be 32 km² and its extent of occurrence 502 km². The number of locations, based upon Rusa Deer as the main threat, is estimated to be five. A continuing decline has been observed in its extent of occurrence, area of occupancy and quality of habitat. Continuing decline can be inferred in the number of mature individuals. Using criteria B, P. davidsonii is assigned a status of Endangered B1ab(i,ii,iii,v)&2ab(i,ii,iii,v). While it is not currently included in a formally recognized protected area, Podonephelium davidsonii occurs in the Conservatoire Botanique de Tiéa, a 32.5 ha parcel located in an area that was previously private land managed by the Programme Forêt Sèche, but which was recently bought by North Province and is scheduled to become a permanent reserve in the near future. The population size is unknown but it would be wise to make efforts towards an estimation of the population size.

Geographical area


Podonephelium davidsonii is an endemic tree of New Caledonia restricted to the west coast of Grande Terre, from Moindou to Pouembout.

Population


Population size is unknown.

Habitat


This species is restricted to sclerophyllous forest at 10-40 m elevation along the central west coast of the main island, Grande Terre.Sclerophyllous forests in New Caledonia are the most heavily impacted native vegetation type in New Caledonia, of which just 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 davidsonii 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 deer 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 davidsonii is not protected by local legislation. Dry forests are a patrimonial ecosystem protected by the Code de l'Environnement of the Province Sud.One sub-population occurs in the Conservatoire Botanique de Tiéa, a 32.5 ha parcel located in an area that was previously private land managed by the Programme Forêt Sèche, but which was recently bought by the Northern Province and is scheduled to become a permanent reserve in the near future.This species would benefit from further in situ and ex situ conservation actions. It is moreover recommended to get an estimation of the number of mature individuals.

Bibliography


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.

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

Experts


Assessor(s): Tanguy, V.

Reviewer(s): Schatz, G.

Contributor(s): Barrière, R., Munzinger, J., Butin, J., Fleurot, D., Barrabé, L., Vandrot, H.


Geographical distribution