Why do Ituri Forest soils deteriorate quickly after the forest is cleared?

The soils of the Ituri Forest are inherently fragile, characterized by a thin layer of humus and acidic compositions derived from Precambrian rocks. When the forest vegetation is cleared, these soils deteriorate rapidly due to their exposure to the intense equatorial sun and high levels of rainfall.1

This degradation occurs because the protective forest canopy is removed, leaving the soil vulnerable to the elements. In the tropical environment, heavy precipitation frequently leaches essential nutrients out of the soil, and the lack of forest cover accelerates erosion, washing away the topsoil necessary to sustain vegetation. Furthermore, because a large proportion of mineral nutrients in such ecosystems is typically bound within the living vegetation rather than stored in the soil, the removal of the forest disrupts the natural nutrient cycle.23

Traditionally, farmers have mitigated this decline by practicing shifting cultivation, which allows the soil to regenerate through the growth of secondary forest. However, when land is maintained in a deforested state, these soils lose their productivity and struggle to recover.143