As the problems of impact assessement are rather intractable, a fairly simple dual approach is proposed. First the major components of environmental impact of current agricultural production systems in Africa (i.e. impact of cropping, livestock keeping, fuelwood and timber extraction and burning) are summarised. Second, "danger zones" in which current and future environmental impacts will be most severe and on which ILCA has focused its problem solving-research is identified.

Presents an overview of population and land use characteristics of the Kurmin Biri, Abet and Ganawwi areas, all in the subhumid zone of Nigeria, with particular reference to ethnic composition, human & cattle population, cultivation densities and extent of fallow land.

Data are given of area planted to beans, production, and yields in the Andean countries during 1964-66, 1974-76, and 1978; production, trade, and consumption during 1963-65 and 1973-75; and production, area, and yield growth rates during 1966-76. Constraints for bean productivity, cropping systems, and the main bean types consumed in the Andean countries are indicated. Finally, the potential of this crop is analyzed and data of land use and population patterns in the Andean countries are included. (CIAT)

Numbers of plant species and individuals were examined relative to land use in an agricultural settlement in the Brasilian Amazon. Land uses were forest, cropped after forest, fallows, cropped after fallow, and pasture. These uses corresponded roughly to farmers` land use changes over time. As expected, species diversity was high in forest. Diversity was also high, however, in fallows of 3-5 years--as a result of both survival/reestablishment of forest species and appearance of plants not found in forest.