Forested resources are composed of woody shrubs and trees. They occur in all habitats apart from environments which are characterized by extreme dryness and/or coldness. Of the 29 million square kilometres of closed forests, 32% are boreal (subarctic), 26% are temperate, and 42% are tropical. Three-quarters of the open forests and shrublands are in the tropics. Forests, wooded grasslands, and shrublands used to cover much more than today's 53 million square kilometres or some 40% of the Earth's land surface. Most forests have been modified at some point by people, and the remaining areas of natural forests are under heavy pressure. Humankind uses forested resources for construction, energetic, medicinal, nutritional and other purposes. A typical forest's non-timber commodities yield may include forage, plant and animal food, medicines, furs and skins, non-wood fibres, essential oils, gums, waxes, latexes and resins. Though they are an integral part of the Earth's vitality, forested resources are used unsustainably and their rate of loss is accelerating due to population growth and development requirements.
Native forests dominated by economically important plants occur over wide areas of the tropics. Such forests represent a concentrated resource that is potentially simple to manage. Throughout the Amazon, palms are one of the most conspicuous of such wild plant resources. They supply materials for housing, weapons, household articles, and food, and are heavily used by all the inhabitants of the region, yet the information that planners require regarding the actual rates at which the palms are utilized, their availability in the forest, or the impact of cultural practices on the future supply of this critical resource, has seldom been recorded. Euterpe oleracea (Acaí) is a forest-dominant palm that is exceptionally abundant in floodplain forests of the Amazon River estuary. Sites where this palm abound are subject to frequent, tide-driven flooding, which imposes serious constraints on conventional forms of agriculture. As a result, local inhabitants are highly dependent on use and management of forest resources. Acaí provides a diverse array of market and subsistence products and indirectly supports a variety of other economic activities. Forests dominated by this palm are subject to various types and intensities of management, which invariably require relatively few inputs and yet appear to significantly increase yields of native forest products. As a result a tight integration can exist between native palm forests and rural communities. It is also the case that palm forests are most viable when they occur on agriculturally marginal sites, which are less subject to competitive and potentially disruptive forms of land use.