Sandrine Petit has a doctorate in geography from the University of Orléans in France, has conducted research in Burkina Faso with IRD, CIRAD and CIRDES, explored agroforestry practices in the Caribbean Islands and Indonesia, and is presently undertaking postdoctoral research in the School of Geography, Nottingham in the UK. Her PhD research concerned "Environment, herding practices, and use of trees by Fulbe agropastoralists in West Burkina Faso. Comparative and systematic study of three situations: Barani, Kourouma and Ouangolodougou". This research explored two aspects of pastoral practices: the factors (ecological, technical and social) which determined the daily range paths of cattle, and how herders chose these paths and how they influenced cattle grazing; and, on the other hand, the uses of tree foliage as fodder and how it induced a different strategy of guarding cattle. The impact of grazing on savanna dynamics and the impact of pollarding on trees were also investigated. The thesis has made an original contribution to scientific debates about pastoralism: the impact of pastoralists’immigration on savanna dynamics; the relation of pastoralists to the environment (are they conservationists or not?); peasants-herders conflicts about land and resources and the integration of livestock raising and farming in savannah production systems.