Balaka (Balaka macrocarpa)

Balaka (Balaka macrocarpa)

Balaka (Balaka macrocarpa) is a small palm that grows to only 8 m high with a trunk from 5-10 cm in diameter.

Also known as: Balaka

Local Names: Balaka, niuniu

Description

Balaka macrocarpa is a small palm that grows to only 8 m high with a trunk from 5-10 cm in diameter.

The tree trunk is green in colour, with conspicuous pale recent leaf nodes; lower down, the trunk is usually heavily adorned with epiphytes and moss.

This palm has a compact crown of 7-12 ascending and slightly arching fronds that reach up to 2.5 m in length, and a bulging green crownshaft.

The fronds bear wide, well-spaced, generally erect, dark green leaflets.

The inflorescence emerges from beneath the crownshaft, and may be large and heavily laden.

However, the large (3-4 cm long and 1.5 cm in diameter), orange-red mature fruit are rarely encountered.

Palms of this species that grow in full shade are larger and more robust than those which emerge through the canopy.

Distribution

This palm is a Fijian endemic restricted to two small areas in each of the two main islands of Viti Levu, Vanua Levu.

The best known population is from the upper Nabukavesi Creek Catchment in Namosi on Viti Levu; and two small populations are known from the Vanua Levu.

 Balaka (Balaka macrocarpa)

Balaka (Balaka macrocarpa)

 Balaka (Balaka macrocarpa)

Balaka (Balaka macrocarpa)

 Balaka (Balaka macrocarpa)

Balaka (Balaka macrocarpa)

 Balaka (Balaka microcarpa) map

Balaka (Balaka microcarpa) map

Habitat Ecology and Behaviour

This palm is an understorey or semi-emergent palm in wet forest from about 200-400 m where it grows on slopes or drainage lines in undisturbed forest and where it may be very locally common. Regeneration in the Nabukavesi population is fair but mature fruit are very rarely encountered. The large fruit are usually eaten as they approach maximum size, but before ripening.

The Masked Shining Parrot Prosopeia personata is the likely culprit, this large parrot rarely, if ever, disperses the fruit, being a seed predator, easily opening the seed with its powerful bill and extracting the soft interior. There are still many aspects of this palm that remain unknown today: its confirmed distribution, growth rate, fruiting season, seed dispersal agent, its habitat requirements – this is much needed information that can contribute towards the conservation and management of this species.

Threats

The current populations of B. macrocarpa are quite small. The population along the Nabukavesi Creek was estimated in 1996 at about 200 mature trees. Mahogany plantations are being established close to this population and if these plantations are extended further, then they will pose a major threat. As is the case for other native palms in Fiji, rats are one of the main predators of Fiji’s palms, and are quite destructive as they not only eat the palm fruit but also the germinating seeds. Rat predation on germinating seeds continues to be a great threat to the regeneration and recovery of the Balaka populations.

This palm is obviously a source of food to the Masked Shining Parrot. The parrot’s predation on the palm probably was not a problem in the past when the population would most likely have been higher. However, with the declining Balaka population, parrot predation is a threat to the regeneration of this palm.

Conservation Status

Other than determining the conservation status of B.macrocarpa as Critically Endangered, and assigning it a Schedule 2 status in the ESP Act (2002), there are no known efforts to ensure that this species does not become extinct.

The location from which the original specimen that was used to describe this palm was taken from is now unknown.

All that is known is that it was collected from the Natewa Peninsula, Cakaudrove, Vanualevu. The best known population of this from the upper Nabukavesi Creek catchment in Namosi on Vitilevu, and even this population is threatened by the spread of Mahogany plantations.

Remarks and Cultural Significance

Other than determining the conservation status of B.macrocarpa as Critically Endangered, and assigning it a Schedule 2 status in the ESP Act (2002), there are no known efforts to ensure that this species does not become extinct. The location from which the original specimen that was used to describe this palm was taken from is now unknown.

All that is known is that it was collected from the Natewa Peninsula, Cakaudrove, Vanualevu. The best known population of this from the upper Nabukavesi Creek catchment in Namosi on Vitilevu, and even this population is threatened by the spread of Mahogany plantations.

References

Doyle and Fuller (1998);
Fuller (1997);
Watling (2005)

Illustration by: George Bennett