Prospects of eucalypt species, including interspecific hybrids from South Africa, for hardwood plantations in marginal subtropical environments in Queensland, Australia

Abstract

In Australia, there has been rapid expansion in recent years of commercial plantations of hardwood timber species, especially of Eucalyptus and Corymbia. In tropical and sub-tropical Queensland the land most likely to be readily available for this planting is in the marginal 650-1000 MAR zone where, potentially, millions of hectares could be planted on cleared land. Optimal forestry plantation practice requires matching of taxa (species-provenances-hybrids) and sites. However, experiment-based identification of taxa with commercial potential has not been accomplished for many regions in this rainfall zone of Queensland. In Brazil, China and South Africa, large viable plantation estates have been developed on marginal lands through use ofhardy, high-yielding interspecific eucalypt hybrids (Eldridge et al. 1993). Eucalypt hybrid breeding is in its infancy in Queensland so the potential exists to accelerate the identification of superior hybrids through introduction and testing ofmaterial developed elsewhere. Based on this overseas experience, bulk seedlots of selected eucalypt hybrids have been introduced, in strict accordance with quarantine requirements, and are now being tested against Eucalyptus and Corymbia species and provenance controls in key regions of Queensland and northern NSW.This paper presents two-year results for three trials in sub-tropical Queensland, indicates the taxa with fastest early growth and considers the potential and suitability of several eucalypt hybrids (seedlings) to marginal sites in Queensland.