Santalum spicatum, the Australian sandalwood, is a tree native to semiarid areas at the edge of Southwest Australia. It is traded as sandalwood, and its valuable oil has been used as an aromatic, a medicine, and a food source. S. spicatum is one of four high-value Santalum species occurring in Australia.
Taxonomy
The Noongar peoples know the plant as uilarac, waang, wolgol, or wollgat.
Description
It is one of four species of the family Santalaceae to occur in Western Australia. It has a similar distribution to quandong and is a hemiparasite requiring macronutrients from the roots of hosts. It has a shrubby to small tree habit, but can grow to 6 m and is tolerant of drought and salt. The foliage is grey-green in colour. The fruit of S. spicatum is spherical, about 3 cm in diameter, and orange in colour. An edible kernel with a hard shell forms the bulk of the fruit; the shell is smoother than S. acuminatum's deeply pitted surface. Germination occurs during warm and moist conditions.
Distribution
Once found across the southwest of Australia, at the Swan Coastal Plain and inland regions of low rainfall, the impact of overharvesting and land clearing for wheat and sheep since the 1880s has greatly reduced the range and population of the species. The marsupial species Bettongia penicillata, known as the woylie, is known to consume and cache the seeds of this species, and is thought to have played a significant role in its dispersal before their decline in the twentieth century.
Commercial use
The harvest and export of S. spicatum has been an important part of the Western Australian economy, at one time forming more than half of the state's revenue. Settlement of the Wheatbelt area was accelerated by the funds generated by sandalwood found there. Distribution and population of the endemic stands were significantly affected during periods of rural development and economic downturn. The state conservator of forests, Charles Lane-Poole, reported in the 1920s that the export value of the 331205 tons shipped from 1845 to date was £3,061,661; the primary use when imported to China was the manufacture of incense. However, Poole also notes the development of an oil extraction industry and use as an effective medical product. Research by the Forestry Products Commission, state universities and private industry was undertaken into the cultivation of the tree and the properties of its wood and nuts. Replanting has occurred at some properties as a land restoration strategy, a food crop and in the long term for harvest. Oil valued at $1 000 per kilogram is produced at Mount Romance in Albany, Western Australia. The area of commercial plantations has risen from seven to 70 km² between 2000 and 2006. The export of 2 000 tonnes of sandalwood a year is primarily sourced from wild stands of the remote rangelands and Goldfields region of Western Australia. The harvest of naturally occurring trees is reduced when compared to the industry of the 19th century. Exports of over 50 000 tonnes in the last decade were related to agricultural expansion by increased access and harvesters.
Cultivation
Germination is difficult, and may depend on the El Niño cycle. Success has been reported by placing the kernels in moist vermiculite in sealed plastic bags at room temperature. Once germinated, seeds should be planted next to a seedling, and watered adequately. The main host species is Acacia acuminata, which is used in plantations, which sustains a 15- to 30-year, long-term host species in loamy sands over clay duplex soils. Rock sheaok Allocasuarina huegeliana, wodjil Acacia resinimarginea, and mulga Acacia aneura are also used.
