The analysis of the nature of goods' property (public, private, common pool) applied to renewable natural resources in Africa and the concept of transaction costs allow a better understanding of traditional institutions and management rules of forests, fisheries, irrigation, pastures and agricultural lands. The increasing density of the rural population and the pressure on ecosystems imply changes in production techniques and institutional adjustments. This paper explores some of the issues related to those evolutions. State decentralisation appears necessary and institutional economics concepts useful for the evaluation of environment projects.
