PERFORMANCE OF 12 SELECTED AUSTRALIAN TREE SPECIES ON A SALINE SITE IN SOUTHEAST QUEENSLAND

The establishment and early growth of 12 species within the genera Euc alyptus, Casuarina, Melaleuca and Tipuana was tested on a saline site in southeast Queensland. Electrical conductivity (EC) in the top 50 cm of soil was measured using an electromagnetic induction method and ca librated against the EC of 1.5 soil:water suspensions. The site was th en stratified into five salinity classes: 0.75-1.0, 1.0-1.25, 1.25-1.5 , 1,5-1.75 and over 1.75 dS m(-1) Relationships were developed for pre dicting the survival and height production of 18-month-old trees. Thes e regressions explained 15-88% of the variation in survival and 2-66% of the variation in height production. Tree species were grouped by de termining the EC level where height production declined by 25% relativ e to that at 0.75 dS m(-1). Casuarina glauca, Melaleuca bractesta, Euc alyptus moluccana, Eucalyptus camaldulensis, Eucalyptus tereticornis a nd Eucalyptus raveretiana were all highly salt tolerant (25% reduction s over 1.5 dS m(-1)). Casuarina cunninghamiana, Eucalyptus grandis, Eu calyptus melliodora and Eucalyptus robusta exhibited moderate salt tol erance (25% reductions between 1.0 and 1.5 dS m(-1)). The responses to increased salinity of Tipuana tipu and Eucalyptus intermedia (25% red uctions at less than 1.0 dS m(-1)) suggest that these species are not suitable for revegetating similar saline sites.