Mangium, Hickory Wattle, Black Wattle
In Australia, this species occurs only in northern Queensland where it has very limited distribution in the coastal tropical lowlands. It extends through southern Papua New Guinea into eastern Indonesia. Its main occurrence is between latitudes 8-18o S and from sea level to 300 m.(QLD)
A very fast growing tree to 30 m tall with a straight trunk. It is relatively short-lived and trees with a diameter of over 50 cm are rare. Mature phyllodes are very large, up to 25 cm long and 5-10 cm wide. They are dark green, hairless and characterised by four main longitudinal nerves. The white or cream flowers are in rather loose spikes up to 10 cm long. Flowering is in May and the seed matures in October-December. The pods are about 7 cm long and 3-5 mm wide, slightly woody, and tightly coiled when ripe. Seed production can start as early as 2-3 years of age. There are about 64 000 viable seeds per kilogram. Seeds need pre-treatment with boiling water for about 30 seconds to promote germination.
Ecology/Way of Life:
It is found in the humid tropics where temperatures are high and equable throughout the year. The area is frost-free. Annual rainfall is in the range 1500-3000 mm with a strongly developed summer maximum. In Queensland, Acacia mangium grows on acid podzolics and red and yellow friable earths of moderate to low fertility in the foothills of the coastal ranges, and on sandy or loamy alluvium on the coastal plain. This species grows on the margins of rainforest, or in open forest and woodland, especially where there is disturbance by fire.
Interaction with Humans/Threats:
Acacia mangium has become a major plantation species in the humid tropical lowlands of Asia due to its extremely fast growth, and tolerance of very acidic and infertile soils. Plantations in Indonesia and Malaysia are the resource base for a large pulp and paper industry. The timber can be sawn easily, polished and turned. It is suitable for furniture and resembles the better-known blackwood (Acacia melanoxylon) in appearance. It has also been sliced for veneer and at one time was used locally for house construction. Its dense evergreen foliage makes this species a useful shade, screening and soil cover crop. Its flowers provide bee forage and contribute to honey production. It is sometimes planted in mixture with other trees to maintain or improve soil fertility.
Acacia mangium was described in 1806 by Carl Ludwig von Willdenow, a botanist in the Berlin Academy of Science. Its name comes from the Greek akakia = a thorny plant, specifically Acacia arabica; and the Latin mangium montanum, which refers to the tree's apparent resemblance to mangroves in Indonesia.
Awang, K. and Taylor, D. (eds.) 1993. Acacia mangium growing and utilization. MPTS monograph series no. 3. Winrock International and FAO, Bangkok. 280p.
Doran, J.C. and Turnbull, J.W. (eds.) 1997. Australian trees and shrubs; species for land rehabilitation and farm planting in the tropics. ACIAR Monograph no. 24. Australian Centre for International Agricultural Research, Canberra. 384p.
Turnbull, J.W., Crompton, H.R. and Pinyopusarerk, K. (eds.) 1998. Recent developments in acacia planting. ACIAR Proceedings no. 82. Australian Centre for International Agricultural Research, Canberra. 383p.
Topics:Soils Germination Vegetation types Fire Timber Agroforestry Honey Climatic zones Fodder Firewood Nitrogen-fixation
Text & map from Australian Trees and Shrubs, courtesy Australian Centre for International Agricultural Research; text edited by J. Turnbull; photo courtesy M. McDonald.
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