Dr. Stephan Krall, studied biology at University Hamburg and made his dissertation at Humboldt University Berlin. He works since 1981 for the German Development Cooperation (GTZ). He spent eight years in agricultural projects in West Africa (Togo, Benin). His dissertation is on pearl millet pests in Niger (West Africa). He was many years in charge of implementation and research projects in the field of pest control and agriculture. Currently he is manager of a sector programme on sustainable management of resources in agriculture. In this position he recently organized a workshop on commons as a future for agriculture in the 21th century.