Agathis silbae de Laub.

Araucariaceae

Endemic to Vanuatu where, although it is not directly threatened, the population is small with perhaps less than 1000 mature individuals.

Associated Names:

santo kauri, hoe and khoe

Description

Taxonomic notes

This species has previously been misidentified as Agathis macrophylla, which occurs on the three southernmost islands of Vanuatu, not on Espiritu Santo.

Distribution

Endemic in Vanuatu on the west coast of Espiritu Santo (Cumberland Peninsula and Mt. Tabwémasana ('Santo Peak')) It has an estimated extent of occurrence (EOO) of about 104km² and an area of occupancy (AOO) estimated to be about 12km². It occurs at altitudes between 450 and 760m above sea-level. The occurrence of large trees of Agathis in the interior mountains of the island of Espiritu Santo in Vanuatu has long been known, both to native islanders and at least since 1963 to visitors. In April 1987 G. Bourdy collected numerous herbarium specimens from 'Santo Peak' (Mt. Tabwémasana), where the trees were observed to be abundant, with several very large individuals seen. This was thought to be the only station of the species, but an earlier collection (specimen at K) dating from February 1979 was made at the nothern end of the mountain range on the Cumberland Peninsula on the "top western slopes" (ca. 600m above sea-level.) and so there are at least two sub-populations of this species.

Habitat and Ecology

Agathis silbae occurs as an emergent large tree in tropical lower montane rainforest on the wetter, western and northwestern slopes of the central mountain range. It has been recorded to occur with Calophyllum neo-ebudicum, Cryptocaya turbinata, Dysoxylum sp., Myristica fatua, Podocarpus sp. and Syzygium spp. (Baldwin et al., 1993; Siwatibau et al., 1998).

Human Uses

This species appears to be planted in or near villages on the west coast of the island. There is no evidence of logging of trees in the interior mountains and this is unlikely to happen as the trees, although large, have short boles making them less desirable for timber. Traditionally, the resin has been used for lighting and to caulk canoes, and its soot for tattoos; the bark for medicines; and the root tips for "fattening babies" (Siwatibau et al., 1998; Wheatley, 1992). Some trees are cultivated in coastal villages. Santo kauri was commercially logged by a local operator between 1995 and 1997, and the wood is much in demand. Logging is the principal threat to the species, and Corrigan et al. (2009), who work with the Vanuatu Department of Forests, present detailed recommendations for its management.

Conservation Status

Global status and rationale

Vulnerable D1+2

There appear to be no immediate threats to this species. The size of the population in terms of mature trees is unknown but could fall below 1000 with the subpopulation in the north of the island much the smallest. The AOO as calculated with the mapping of three localities (two “locations”) falls below 20km² so that Agathis silbae meets criteria D1 and D2 for Vulnerable assuming that these estimates are correct

Global threats

There seem to be no immediate threats to this species. Aerial imagery shows the forest cover to be intact in the areas where the wild growing trees have been found. There is little incentive for logging because all the large trees have very short boles and massive branching rendering them of limited use as timber

Conservation Actions

There are no protected areas established in the mountains of Espiritu Santo.