In the current debate on the role of
increase soil carbon in addressing both climate change
and food security, there is consensus that farmed lands
have the higher potential provided the best management
practices are implemented. In the Sahel where
farms usually have few sparse old trees with declining
soil fertility, there is an ongoing re-greening process
with increases in tree cover for which there is still a
dearth of quantified information on its impacts on soil
properties. This research aimed at filling that gap. We
sampled soil using a concentric zone design around
individual trees of dominant species and at different
soil depths (0–10, 10–30, 30–50 and 50–70 cm) in
four Sahelian countries: Burkina Faso, Mali, Niger and
Senegal. The results showed increase total carbon
content of the top 0–10 cm soil, generally with high
sand content ([70%), ranged from 0.16 to 0.44%
(mean 0.23%). Under trees it was a factor 1.04–1.47
higher than away from trees. Different tree species
thrived in different ecological niches and had different
impacts on soil properties, highlighting the need for
site and species matching in restoration activities.
These results suggest that increase vegetation cover in
the Sahel is associated with an increase in soil total
carbon and this trend is more pronounced on sandy
soils.

FMNR  Parkland  Re-greening  Restoration  Soil fertility  Trees