RiVaSoL

Soil erosion in the mountain Rift Valley of Africa – From collapse to recovery of soil resources

Soil erosion is one of the major threats to global soil resources and food security. This is particularly true for the montane region of the African Rift Valley where steep terrain, high rainfall intensity and low soil cover conditions throughout the year promote soil erosion. The extreme soil erosion in that region causes the irreversible collapse over large areas for arable land use due to the uplift of the bedrock in the rooting zone. Reforestation can be one of the most effective erosion control mechanisms and applied correctly, can serve to protect ecosystem services such as carbon storage and biodiversity. However, the recovery of forest ecosystems is highly linked to the site-specific soil degradation stage. To react in time, there is an urgent need to understand the pace of cropland soil loss, the remaining soil volume and the impact of soil degradation on reforestation success. To get a grip on soil erosion processes on landscape scale, ground based monitoring and remote sensing (UAV) technology is fused. This process-based understanding is the fundament for an implementation in meso-scale model predictions that help to understand (i) the soil degradation pace, (ii) the remaining soil resources and (iii) the forest recovery potential.