Abstract

Tropical forests are geographically limited to areas located between the tropics of Cancer and Capricorn. They harbor the largest diversity of species and ecosystem types on Earth. Their importance for the maintenance of stable trace of gas concentrations in the atmosphere is increasingly recognized. As a result, large international projects are currently underway throughout the tropics to understand the global interactions derived from biogeochemical cycling in tropical forests and the consequences of large-scale deforestation for loss of biological diversity and stability of the world climate. Numerous fundamental contributions on the ecology of tropical forests were produced during the last century, describing composition, structure, and functioning of those communities (Richards 1952, 1996, Odum and Pigeon 1970, Walter 1973, Unesco 1978, Vareschi 1980, Leigh et al. 1982, Sutton et al. 1983, Whitmore 1984, 1990, Jordan 1985, Jordan et al. 1989, Proctor 1989, Gómez-Pompa et al. 1991, Mulkey et al. 1996, Kellman and Tackaberry 1997). These contributions served as a conceptual basis for this chapter, aimed at highlighting the functional characteristics of tropical forest plant components. The chapter gives an outline of the distribution and edaphoclimatic characteristics of tropical forest as a basis for the more detailed discussion of diversity and function of main life-forms. The relationships between water and nutrient availability as regulators of the photosynthetic performance of tropical trees are also discussed to assess the role of tropical forests in the carbon balance of the atmosphere.