Growth and survival of Australian tree species in field trials in Thailand.
Field trials of many Australian species (mostly of the genera Acacia, Eucalyptus and Melaleuca) were planted at different sites across Thailand during the period 1985 to 1987. Early results obtained for the trials planted in 1985 and 1986 have shown marked differences between species in growth and survival. Several acacias (e.g. Acacia crassicarpa, A. auriculiformis, A. torulosa and A. julifera) and eucalypts (e.g. Eucalyptus camaldulensis, E. tereticornis, E. citriodora and E. urophylla) were among the fastest growing, while most Melaleuca and Casuarina species were slow growing. Some species (e.g. Acacia oraria, Albizia procera and most Melaleuca species) grew slowly but survived well. A little-known species (Grevillea pteridifolia) grew well with a dense crown, and maintained a healthy appearance throughout the year. Provenance variation was noted for some species. Northern provenances of Acacia crassicarpa and A. aulacocarpa grew faster than southern provenances. Some species were also found to differ in tree form between different sites (e.g. trees of Acacia polystachya and A. holosericea, normally multistemmed with heavy branching at dry sites, were single-stemmed and had light branching patterns at two wet sites).