A study of drivers and dynamics of forest-savanna boundaries in West Africa

Samenvatting (Engelstalig):

Forests and savannas are often seen as separate systems with distinct tree types with different tolerance for fire and shade and no overlap. However we know that soil nutrients and soil water availability can also be an important determinant of vegetation structure. To fully understand biome transitions, also in the light of climate change, there is a need to specifically study the interplay between soil, fire and tree species where forest and savanna meet.

In this thesis, I investigated these components with field studies supported by remote sensing. I found that vegetation structure was associated with soil factors and, that two types of fire were distinguishable including litter fires in forest which cause selection of different tree types. In addition to typical savanna and forest tree types, I found a new group of non-selective tree species. that bridge the gap between forest and savanna and play a role in forest-savanna transition.

This study contributes to the ongoing debate about the relative importance of fire and soil in determining vegetation function and structure and concludes that soil, climate, and fire all interact to create boundaries and transitions in the forest savanna landscape.