Water Use Efficiency‐Based Multiscale Assessment of Ecohydrological Resilience to Ecosystem Shifts Over the Continent of Africa During 1992–2015

Abstract

AbstractThe spatial‐temporal representation is a crucial key for understanding at what extent terrestrial ecosystems can maintain their structure and functions and recover from various ecosystem shifts (drought/wet). Hence, it is vital for sustainable ecosystem management, adaptation, and mitigation practices. This study assessed ecohydrological resilience to ecosystem shifts at contrast water‐limited and well‐watered regions at multiple scales (i.e., country scale, basin scale, climate type scale, and land cover scale) over Africa during the period 1992–2015, based on Standard Evapotranspiration Deficit Index (SEDI) and water use efficiency (WUE) at ecosystem scales, which was obtained from satellite‐derived evapotranspiration (ET) and simulated gross primary productivity (GPP) using the Carnegie‐ames‐stanford approaches (CASA) model. SEDI values indicated that 11 years were characterized by dry conditions, while 13 were wetter years during 1992–2015. WUE, ET, and GPP values indicated increased tendencies mostly in central to central west of African continent. The ecohydrological resilience exhibited that about 68.78% of African terrestrial ecosystems were highly, moderately, or slightly resilient, and about 31.22% were not resilient to ecosystem shifts with 11.28% vulnerably exposed to high risk of ecosystem shift and severely nonresilient. The extent areas exposed to severe ecohydrological nonresilience are distributed in Savannas and barelands land cover types, temperate‐dry summer‐hot summer (Csa), climate type, Mediterranean South Coast (B14), African‐North interior (B3), and Red Sea‐Golf of Aden Coast (b5) basins; and the four countries, namely, Egypt, Mauritania, Niger, and Tunisia. These findings may provide insightful scientific information about vulnerable regions for policy making and ecosystem management and increase the necessary awareness for taking reasonable adaptation mechanisms, such as afforesting open lands to increase the area of vegetation cover (i.e., choosing the drought or wet‐tolerant plant species) and water conservation and management measures to ensure the sustainability of terrestrial ecosystems under ecosystem shifts over the African continent.