The world now has 50 million hectares of fast-growing timber plantations and the proportion of the world’s wood supplies coming from plantations is increasing. It estimated that within 30 years the plantation area will have increased by 60% and plantations will dominate more and more of our landscapes. In the pulp and paper industry a few multi-national companies control vast areas of industrial monocultures – mainly of exotic species. Even the multitude of small plantations and woodlots in the developed and developing world are composed largely of exotic species.

The number of species exploited for industrial wood is decreasing and...

Over the past few decades there has been a steady expansion of forest plantations across the tropics. This is driven by two main forces: a dwindling supply of wood from natural forests and an increase in demand for various wood products as human populations grow and life styles change. The reasons for the decline in supply from natural forests are many, ranging from over-exploitation to increasing desire to conserve the forests for environmental benefits. The spectacular increase in recent times in the per hectare yield from plantations through genetic selection and intensive management has also promoted reliance on plantations. Although...

Acacia mangium Willd. (Leguminosae, Mimosoideae) is currently a widely planted exotic in the tropics, particularly in Southeast Asia. Its natural distribution is limited to latitudes from 10°S to 19°S, in Queensland, Australia, the western province of Papua New Guinea, and two provinces in Indonesia viz., Irian Jaya (particularly the southeast district of Merauke) and Moluccas (three small islands of Sula, Ceram and the Aru) (Pinyopusarerk et al. 1993). The species commonly occurs in coastal lowlands up to 800 m altitude. The plantation history is short, being introduced into Sabah, Malaysia in 1966 using seed of a very restricted genetic base...

Much of the discussion in the literature on the comparative susceptibility of exotic versus indigenous plantations to insect outbreaks has been based on theoretical considerations. In the past, reliance on theory was unavoidable because there was very little empirical data, and some guidelines were needed before embarking on large-scale cultivation of exotics. Unfortunately, in the absence of sufficient empirical data, opinion was sharply divided between the protagonists and antagonists of exotics, and the planting programme with exotics went ahead without regard to the scientific pros and cons. As indicated in the Introduction, a number of extraneous issues – social, political...