Introduction

Plantation forestry is now a major activity in the forestry sector in the tropics, with a large number of species grown in plantations to serve a variety of purposes (see Chapter 1, Section 1.5). For example, about 170 species have been tried in plantations in India (Ghosh, 1977), 80 in Malaysia (Appanah and Weinland, 1993) and 24 in Indonesia (Cossalter and Nair, 2000). Increasing numbers of species are now being put on plantation trials as most commercially exploited species are potential candidates for plantations, and their numbers are large. For instance, in Cameroon alone there are 400 commercially exploited species (Foahom, 2002). Because of the large number of plantation species, it is impracticable to draw up a list of all species planted and deal with their pests. Such a treatment would be encyclopaedic and would not permit us to see the forest for the trees. A smaller number of species such as eucalypts, tropical pines and acacias have dominated the plantation scenario in the tropics, mainly for the production of pulpwood, but they are not representative as there are many other valuable tree species that are locally important and planted over smaller areas. In order to get a balanced view, we shall consider a representative group of plantation species. Trees commonly planted in the tropics are chosen, irrespective of the extent of area planted and whether they suffer from serious pest problems or not.