Land use dynamics, tree diversity and local perception of dry forest decline in southern Burkina Faso, West Africa

Abstract

Conversion of tropical forests into cropland and pasture has risen incessantly during the last few decades. With the aim of providing evidence for informed-decision on sustainable forest management, this thesis examined the dynamics of land use change in Sissili province, southern Burkina Faso, whether tree diversity and natural regeneration are favored in protected forests under varying human population pressures and local perception of forest decline. Spatial analysis revealed a rapid land use change both at local and regional scales over the past 16 years, characterized by a high conversion rate of forest to agricultural land, driven by rural immigration, changes in farming systems and fuelwood extraction. The protected forest harbored relatively less species (45) than the unprotected forests (58). Irrespective of the forest conservation status, stem density and basal area were higher in a site with higher human population density than otherwise. Shannon’s measure of evenness and Fisher’s diversity index were significantly high in the less populated site and unprotected forests, respectively. Seedling density did not vary significantly between protected and unprotected forests and sites with varying human pressures, and the majority of the species was characterized by very low seedling density, with a clumped population distribution. A survey on uses of forests and perception on their decline revealed 82 plant species that are being used for various purposes (food, medicine, energy, animal feed and construction), suggesting the key role the forest resources play in poverty reduction and sustaining seasonal shocks (like food scarcity or income generation). The thesis draws the following major conclusions: 1) the size of cropland increases at the expense of declining forest cover both at local and regional levels; 2) the designation of protected areas by itself appears ineffective in ensuring conservation of tree diversity and natural regeneration in the Sudanian dry forest reserves; and 3) the local people depend on the forests to meet their subsistence, energy, income and medicinal needs, with distinct variability between gender, residence status, and ethnic group. The decline of the dry forest in the region has been perceived by the various stake-holders. To effectively protect the remaining dry forests, the forest management strategy should promote the idea of “conservation by utilization” where ownership and management right should be devolved to the local people and equitable benefit-sharing mechanisms established.