Yaka (Dacrydium nausoriense)

Yaka (Dacrydium nausoriense)

Yaka (Dacrydium nausoriense), one of Fiji’s renowned primitive conifers, is a member of the family Podocarpaceae.

Also known as:

Local Names: Yaka, Tagitagi

Description

Yaka, one of Fiji’s renowned primitive conifers, is a member of the family Podocarpaceae. There are two species of Dacrydium in Fiji, both with the Fijian name Yaka, and both very valuable timber trees. The endemic yaka described here can grow up to 12-24 m in height. Like other podocarps, the reproductive structure is a cone-shaped pollen cone. The fruits are purplish or brownish and become black at full maturity.

Distribution

This species is endemic to Fiji, and is only found on Viti Levu. Collections and records have been made only from the Nausori highlands on the border of the provinces of Ba and Navosa on Viti Levu. Its reported presence at Korosirisiri on Vanua Levu, remains to be confirmed.

 Yaka (Dacrydium nausoriense)

Yaka (Dacrydium nausoriense)

 Yaka (Dacrydium nausoriense) map

Yaka (Dacrydium nausoriense) map

Habitat Ecology and Behaviour

Yaka occurs in dense forests at an elevation of 180-600m, in the sub montane forest zone. Immature inflorescences have been observed in May and October, and fruits between February and October. Other than the above information, there is nothing else known of this endemic and highly valuable tree.

Threats

Because of its similarity to the more common Dacrydium nidulum and their high value as a timber species, this species is threatened by over-exploitation and habitat destruction. Its restricted range and unknown ecology puts it at a high risk of population decline and most probably extinction. Improper forest management also poses a threat to the survival of this species.

Conservation Status

When first described D. nausoriense was reported to be quite common in the very limited area where it occurs. However, that was over 50 years ago and there has been no recent population survey, and in the meantime all of the Nausori Highlands forest has been very heavily logged, badly fragmented and much of it cleared . The status of the population, and its distribution outside the Nausori Highlands remains unknown. There is an urgent need to confirm this information so that appropriate conservation measures can be taken.

This species is listed as Endangered in the IUCN Redlist of Threatened Species.

Remarks and Cultural Significance

When first described D. nausoriense was reported to be quite common in the very limited area where it occurs. However, that was over 50 years ago and there has been no recent population survey, and in the meantime all of the Nausori Highlands forest has been very heavily logged, badly fragmented and much of it cleared . The status of the population, and its distribution outside the Nausori Highlands remains unknown. There is an urgent need to confirm this information so that appropriate conservation measures can be taken.

This species is listed as Endangered in the IUCN Redlist of Threatened Species.

References

Alston (1982);
Keppel et al. (2006),
Smith (1979).