Santalum Acuminatum - Ecology

Ecology

The plant is hemi-parasitic; able to photosynthesize, but using the root system of other plants to acquire nutrients other than sugars. The Santalum genus of plants attaches to other species, in a non-destructive way, sustaining itself by their provision of nitrogen, shade, and water. The roots of the species have pad-like adaptations, that nearly encircle the host's root, this is typical of this genus of sandalwoods. Hosts can be other trees, or grasses, usually several plants are utilised. The taxa recorded in this relationship are species of genera; Acacia, Maireana, and Atriplex, and many others, including hemiparasites such as Exocarpos sparteus. This mechanism allows the plant to acquire 70% of its nitrogen, and some of its water, requirements from the roots of other trees and shrubs.

The tree occupies a diverse and widespread range of habitat, including creek beds, granite, gravel plains and sandy dunes. It is tolerant of drought, salt and high temperatures, and need not have a nutrient rich environment. The seedling can become established in the shade of its host, reaching for full sun once developed, so the plant is usually intermingled with host and other species.

The environs of the distribution range are subject to frequent bushfires, this requires the plant to regenerate from its roots, so the species is rarely found as an advanced tree. Those specimens exposed to bushfire and soil disturbance will occur as sprawling multi-stemmed shrubs. The plant's regrowth from the root system gives this species a lead over shrubs that recur from seed. Trees with a single main stem are in locations remote from these factors. The habit of older trees may overwhelm the adjacent plants; by monopolising the sunlight and parasitising roots of plants beyond its own canopy.

The foliage, being much paler than other trees and shrubs, makes the plant conspicuous in bushland and scrub. An occurrence of an unmolested specimen is recorded at Woodman Point in Western Australia, an area remote from the high intensity fires of altered regimes.

Emus will eat the fruit, it forming an important part of their diet, the nut remains undigested in their droppings. This is the usual method of S. acuminatum seed dispersal, when it is within the Emu's range.

A number of species interact with this plant, in a number of complex relationships, a noted example being Paraepermenia santaliella; the Quandong Moth of the Epermeniidae family. Other creatures, such as larvae of Nitidulid beetles and the Wood white butterfly, also feed on Santalum acuminatum.