The threat of a rapidly growing population has been at the forefront of many environmental debates about the Sahel with particular emphasis on land degradation due to the postulated increasing cultivated area needed to fulfil the food requirements. The deficiencies of such purely unidirectional perceptions of land use changes became apparent, however, already in the beginning of 2000, when researchers within the Land Change Science community raised their concerns about general narratives of field expansions that were assumed to progress linearly and be solely driven by population growth. Calls for more research on Sahelian land use changes have thus multiplied as the complexity and sometimes intricate processes of land change became apparent, and especially, the need for novel approaches that combine different perspectives has continuously been highlighted.
As part of the interdisciplinary research program LASYRE (LAnd SYstem REsilience), this thesis responds to thes calls by applying a portfolio of different perspectives to the study of Sahelian land use changes and the causal mechanisms behind them. It examines the land use changes that have taken place in Northern Burkina Faso over the last decades and how local people’s land use decisions are influenced by various factors such as crop prices, off-farm job opportunities and rainfall variability. This is done by applying four complementary perspectives that represent different temporal and spatial scales as well as some influential theoretical lines of thought within the Land Change Science community. The four perspectives are system dynamics, resilience theory, a rationality perspective, and a multifunctional agriculture perspective.
The thesis shows how the previous tendency to field expansion in the Sahel has been replaced by a very fluctuating cultivated area despite continued population growth. Instead, land use changes can be attributed to driving forces such as the possibilities of buying food crops at low prices in the local villages, and the engagement in non-agricultural activities such as migration and gold-digging. But recent land use decisions seem also to be highly influenced by individual rationalities. For example, field expansion has been undertaken for individual reasons of prestige rather than driven by the food requrements of a growing population. Moreover, the whole aim of farming has somewhat moved beyond having food production as the primary outcome as crop residues used for fodder have become the major focus. The thesis thereby demonstrates the need to re-examine the evidence on which stories of field expansion are based and questions the way in which Sahelian land use changes are conceptualized.
At the overall methodological level, this thesis demonstrates how the application of different approaches and perspectives may advance the understanding of Sahelian land use changes. The purpose of using multiple analytical frameworks has been to select complementary perspectives, and to demonstrate the value of this complementarity, rather than to identify the single best method for analyzing Sahelian land use systems. The thesis for example illuminates how system dynamics and resilience theory, on the one hand, provide attractive means for exploring system feedbacks and trajectories of change, yet, on the other hand, lack the inclusion of villagers as reflexive agents. This is then counterbalanced by including the rationality and the multifunctional agriculture perspective, which, if applied on their own, would fall short in relation to exploring system feedbacks.