Acacia mangium Willd is an important multipurpose tree for the tropical lowlands. It is one of the most widespread of the fast-growing tree species which are used in plantation forestry programmes throughout Asia, the Pacific and the humid tropics. It has also become naturalised in Brazil, Puerto Rico and many other areas. Due to its rapid growth and tolerance of very poor soils, Acacia mangium is playing an increasingly important role in efforts to sustain a commercial supply of tree products whilst reducing pressure on natural forest ecosystems. Fast-growing Acacia plantations provide industrial wood for Vietnam’s wood-processing, pulp and paper...

Botanical name: Acacia mangium Willd

Family: Fabaceae

Subfamily: Mimosoideae

Synonyms: Mangium montanum, Racosperma mangium

Arr (Papua New Guinea), Black wattle (Australia, UK and USA), Brown salwood (Australia, UK and USA), Kayu safoda (Peninsular Malaysia), Keo tai tuong (Vietnam), Kra Thin Tepa (Thailand), Mangge hutan (Indonesia), Tongke hutan (Indonesia) (Turnbull 1986).

Acacia mangium is a fast growing, nitrogen fixing, evergreen with phyllodes that serve as leaves (NFTA 1987). It is a medium-sized to fairly large tree measuring up to 35 m tall. Its bole is branchless for up to 15 m, and can measure up to 90 cm in diameter. The...

The small flowers are grouped in spikes up to 10 cm long and occur singly or in pairs in the leaf axils near the branch tips. The trees flower annually, usually at the end of the rainy season or the early part of the dry season, and the fruits ripen 5–7 months after flowering. Acacia mangium starts to flower and produces seeds 18–20 months after planting. Flowering occurs in Australia in May, with fruits maturing in late October–December. Fruits ripen in Indonesia in July, in Papua New Guinea in September (Turnbull 1986), and in Central America in February–April...

Seeds are sowed in germination trays or beds, and when seedlings have about three leaves they are packed into plastic nursery bags where they grow to a plantable size (Turnbull 1986). Seeds are sometimes sowed directly into 1–2 litre nursery bags, a method which requires pricking to one plant per bag after seedlings emerge. The appropriate height for transplanting is 25–40 cm, which is reached when the seedlings have been in the nursery for 9–16 weeks. Although Acacia mangium seedlings usually auto-inoculate with Rhizobium symbiotic nitrogen fixers, artificial inoculation in the nursery is recommended (Von Carlowitz et...

Weeding is important in industrial plantations as it helps meet production requirements and quality control standards. In order to prevent trees suffering any serious slowing in growth, weeding should be timed to coincide with when the trees are least susceptible to damage. Generally, the greater the area weeded around the tree, the less competition the tree is subjected to and therefore the better it grows. Typically, spot weeding is less effective than strip weeding, whereas clean weeding is optimum. Lowery et al. (1993) concluded from a review of weed control in tropical forest plantations that complete weeding in most cases...

Height and diameter are important inventory measures for estimating tree volume. In the study area in Phu Tho Province, Vietnam, samples were collected from 104 Acacia mangium plots representing different age classes (1–7 years). Michailow’s growth function was used to estimate the diameter and height of the stand:

\[H=a*\exp (\frac{-b}{\textrm{age}})\; \; \; \; D=a*\exp (\frac{-b}{\textrm{age}})\]

Table 1 presents growth in diameter and height of samples from 104 Acacia mangium plots.

The annual growth in diameter and height from 1 to 5 years of age is nearly identical. These plantations were evaluated to determine the mean annual increments. They achieved a minimum increase in diameter of 2.7...