Local-scale secondary water inputs modulate seasonal vegetation cover
decay rate across Africa
Abstract
Next to precipitation, secondary water sources emerging from shallow
groundwater and lateral redistribution of soil moisture, together with
soil properties modulating their accessibility are highly important in
water-limited ecosystems. However, effects of these land-associated
secondary inputs are not well known over large domains given the
mismatch of spatial scales of processes. Here, we quantify the role of
land properties on the spatial variations of seasonal decay rate of
vegetation cover over water-limited regions of Africa, using machine
learning. Over the study domain, 17 % of these variations are directly
attributed to land properties, and 16 % are attributed to interaction
effects of land properties with climate and vegetation. Locally, total
land attributed variations account for more than 60 % in hotspots with
different land properties like shallow groundwater, complex topography,
and favourable soil properties. Our findings lend empirical evidence for
the importance of local-scale secondary water inputs over large domains.