Sunday, November 15, 2015

Sandalwood Trees in Hawaii

Sandalwood trees (Santalum sp.) are classified as hemi-parasites. The term describes a plant that is green and can produce its own food but also derives water and some nutrients by attaching to the roots of other plants. This process can effectively join together whole plant communities through their root systems. The plants that donate nutrients to sandalwood are called hosts; sandalwood trees do not grow well without a host. In fact, this ‘inter-cropping’ is not only possible but necessary. 

According to the publication, Species Profiles for Pacific Island Agroforestry, S. ellipticum, one of four species known as Hawaiian sandalwood, can “… successfully develop into relatively large individuals when growing with endemic species such as Wikstroemia sandwicensis (‘ākia) and a fan palm Pritchardia remota (loulu) in windward, lowland areas. In more xeric (dry) environments it has developed successfully in association with the endemic shrub Chenopodium oahuense (‘āheahea) and Chamaesyce hypericifolia. Apparently S. ellipticum, is flexible in the species it can parasitize for needed nutrients.”
Santalum ellipticum is endemic to the Hawaiian Islands. It is found as a sprawling to bushy shrub near the ocean shore. It is occasionally found as a larger shrub to small tree in dry gulches, on slopes, and frequently in rocky habitats. S. ellipticum is adapted to arid habitats with typical summer drought in leeward lowland locations.
Hawaiian sandalwood species generally resist most insect attack; sometimes infestations of whitefly or scale insects can be found. Insecticidal soap may be used to treat such infestations. Slugs and snails will also feed on newly sprouted plants. The trees generally tolerate a broad range of soil conditions but show a preference for well drained neutral to slightly alkaline soils.  Since many Hawaiian soils tend to be acidic, an application of lime would be appropriate to bring the soil closer to neutral. The wood of the sandalwood trees is often used for carving handicrafts, art, musical instruments and decorative furniture.