The Soga (Metroxylon vitiense) is a large conspicuous palm that grows to 15m in height.
Also known as: Sago Palm
Local Names: Soga, Sogo, Niu soria, Seko
Description
The Soga is a large conspicuous palm that grows to 15m in height. It has a single thick brownish trunk; usually with a tattered appearance through the persistence of dead fronds. The crown arches, with erect fronds up to to 5 m in length; the frond bases bear wickedly long spines in neat rows. This palm has no crownshaft. At maturity, after about 15 years, this palm produces a large, twice-branched inflorescence up to 4 m in height. A large number of flowers are produced, and over a period of 12-15 months these develop into fruit. The attractive fruit are large (5-7 m in diameter), brown with light scalloping, and have a distinctly scaly appearance and feel. By the time the fruit fall, all the fronds have died and fallen back, the palm tree dies thereafter.
Distribution
The current distribution of the Soga is confined to South-eastern Viti Levu (Wainiyabia, Culanuku, Galoa, Pacific Habour, Lobau and Nabukelevu) and Ovalau. There is one confirmed occurrence on Vanua Levu just outside of Savusavu. Habitat Ecology and Behaviour
The Soga clearly thrives only in swampy habitats: in valleys upstream of coastal swamps (on collovium and alluvium soils); and in coastal lowland areas.
This palm is associated with sedges and native mosses and pandanus which also grow in the peat swamps. Like most palms, the soga propagates by seed. The large buoyant seeds fall under the parent tree and float in the water until it can find a suitable place to finally germinate. In the upper Navua gorge, half eaten fruit from bearing palms indicate another dispersal agent – the large, endemic Masked Shining Parrot and bats are the most likely suspects.
Threats
The drainage of Fiji’s coastal plains has been an ongoing threat to this palm for many years. However, concern for the status of this endemic palm has intensified greatly with the increasing demand from the tourism industry for use of the leaves for thatching. Recent research by Rounds (2007) has shown that the unsustainable harvesting of the sago palms, and no replanting in harvesting areas have resulted in an almost 50% reduction of the distribution and size of the surviving population. This has increased the vulnerability status of the sago palms, promoting it to the IUCN Endangered status. Rats feed on young shoots, killing the seedlings. Extraction of the edible palm heart is also an increasing concern as it requires that a whole tree is cut down, resulting in the death of the palm tree.
Conservation Status
This palm is endemic to Fiji, and was formerly much more common on the alluvial plains of south east Viti Levu and the Rewa Delta. Now they only occur in small disjunct pockets of this historical range. Of the 12 remaining populations only three are considered to be reasonably secure, the remainders are either seriously threatened or near extirpation. NatureFiji-MareqetiViti is currently leading a consortium of NGOs and government agencies to draw up and implement a Species Recovery Plan for the sago palm.
Remarks and Cultural Significance
This palm is endemic to Fiji, and was formerly much more common on the alluvial plains of south east Viti Levu and the Rewa Delta. Now they only occur in small disjunct pockets of this historical range. Of the 12 remaining populations only three are considered to be reasonably secure, the remainders are either seriously threatened or near extirpation. NatureFiji-MareqetiViti is currently leading a consortium of NGOs and government agencies to draw up and implement a Species Recovery Plan for the sago palm.
References
McClatchey (2006);
Rounds (2007);
Smith (1979);
Southern (1986);
Watling (2005).
Front Page Photo: Dick Watling