Tropical regions are likely to experience more intense rainfall events in the future.
Such an increase in rainfall intensities will affect soil and groundwater recharge, with
potential consequences for millions of people. However, little is known about the
impact of tree cover on soil and groundwater recharge under higher rainfall intensities.
Here, we investigated the effect of tree cover and rainfall intensity on soil water
drainage in an agroforestry parkland in West Africa. We collected soil water drainage
from lysimeters located at 50 and 150 cm depth in both small and large open areas
among trees, which represent contrasting degrees of tree cover, and analyzed a
subset of water samples for δ18O and δ2H to gain insights into the mechanisms of
water flow within the soil profile. We found that under high rainfall intensities
(20 mm d−1), the median daily soil water drainage amount at 150 cm was 13 times
higher in the small compared with the large open areas, whereas at 50 cm, there were
no significant differences. Low rainfall intensities (

drylands groundwater recharge intense rainfall macropores tree cover