AbstractThe following two articles are extracts fromTropical Forest Ecosystems: a State-of-Knowledge Reportprepared by Unesco/UNEP/FAO.The first ‘Tropical Forests and the Biosphere’, describes the protective, regulative and productive functions of the tropical forest at the ecosystem level. The second article, ‘Socio-cultural Consequences of Ecosystem Transformation’, comes from the section entitled ‘Civilizations and Societies’. It describes the transformations that occur within human societies, whose habitat is the tropical forest, when the ecosystem of that forest is altered.