Establishment and growth of sandalwood (Santalum spicatum) in south-western Australia: the influence of host species

Abstract

Summary This study examined the performance of sandalwood (Santalum spicatum) parasitising two N2-fixing woody hosts (Acacia acuminata and Allocasuarina huegeliana) and a non N2-fixing host (Eucalyptus loxophleba subsp. loxophleba) on farmland at Kwobrup, Western Australia. The host seedlings were planted in 1991, and the S. spicatum were direct seeded at host age five years. Survival and growth of the S. spicatum were assessed at age three years. S. spicatum survival was significantly higher when planted next to A. acuminata (86 %) than A. huegeliana (29 %), and all seedlings next to E. loxophleba subsp. loxophleba died within two years of establishment. Mean height and stem diameter of S. spicatum parasitizing A. acuminata were significantly greater than those parasitising A. huegeliana. The initial presence of S. spicatum did not reduce host survival or growth. The foliar N and K concentrations, and the K:Ca ratio were significantly higher in S. spicatum parasitising A. acuminata than A. huegeliana. However, the S. spicatum attached to A. huegeliana had significantly higher concentrations of foliar P, Ca and Mg. The leaf and stem water potentials (Ψleaf' Ψstem) of S. spicatum trees were the same or significantly lower than their paired hosts, at pre-dawn and midday, in February-March 1999, the stem water potentials of the S. spicatum: A. acuminata pairing were significantly lower than the S. spicatum: A. huegeliana pairing.