'Forgotten' native tree holds promise for pastoralists
A LITTLE known, uniquely Australian tree could prove a boon to pastoralists in northern Australia. Known to researchers as the Belmont siris, Albizia canescens was "re-discovered" by CSIRO's Dr Brian Lowry. Rare elsewhere, it is quite common on Belmont, a grazing property near Rockhampton used for CSIRO cattle breeding research for many years. "A century ago, this tree was well-known for cabinet-making timber," Dr Lowry said. "It must have been a lot more common then. Now it is all but forgotten and I could find no mention of it anywhere in authoritative reference works." Dr Lowry believes this tree, which does not have a common name, has potential for both boosting animal production and yielding quality cabinet wood. "It is a dual purpose tree, as the leaves are highly palatable and fallen leaf and pod can be eaten," he said. "And like the siris (Albizia lebbeck), it has a remarkable ability to promote grass growth below the canopy. "Milling a log suggests that the timber is also highly suitable for cabinet making. "Although the Belmont siris is not abundant, it is found over a wide area of tropical northern Australia from the Kimberley to near Rockhampton. It is not only a native tree, but endemic ‹ found only in Australia. "It is something of a mystery as to how it has survived at all, being so palatable. On the other hand, it almost certainly has been declining." Belmont siris is an inconspicuous tree, occuring scattered in eucalypt woodland and has an open crown and glaucous foliage much like eucalypts. "Anyone recognising it as a tree legume is then likely to equate it with Albizia lebbeck," Dr Lowry said. "However, there are obvious differences, in leaf and bark, and particularly the flowers ‹ large and fluffy in siris, very small in canescens. "The fallen pods are similar to siris, and are palatable to sheep. They are, however, produced more sparingly. The green leaf is highly palatable and, like siris, has almost no tannin content. "Fallen leaves have similar properties but leaf fall is not as profuse. Isolated trees have a strong effect on promoting sub-canopy grass, which is a very positive feature." Dr Lowry said the advantage of Belmont siris was that it was already present out in the native rangelands. "This shows that not only can it grow in these areas, but that some landholders already have it," he said. "It is likely that few people realise what a valuable resource it could be. We have not much data on it, only enough to know it's a valuable tree to have around." Dr Lowry's research is supported by the joint venture agroforestry program of the Rural Industries Research and Development Corporation (RIRDC). pPointer???