TY - JOUR

T1 - Changes in vegetation-water response in the Sahel-Sudan during recent decades

AU - Lu, Tingting

AU - Zhang, Wenmin

AU - Abel, Christin

AU - Horion, Stéphanie

AU - Brandt, Martin

AU - Huang, Ke

AU - Fensholt, Rasmus

N1 - Publisher Copyright: © 2024 The Authors

PY - 2024

Y1 - 2024

N2 - Study region: The Africa Sahel-Sudan region, defined by annual rainfall between 150 and 1200 mm. Study focus: Understanding the mechanism of vegetation response to water availability could help mitigate the potential adverse effects of climate change on global dryland ecosystems. In the Sahel-Sudan region, spatio-temporal changes and drivers of the vegetation-water response remain unclear. This study employs long-term satellite water and vegetation products as proxies of water availability and vegetation productivity to analyze changes in vegetation-water sensitivity and the cumulative effect duration (CED) representing a measure of the legacy effect of the impact of water constraints on vegetation. A random forest model was subsequently used to analyze potential climatic drivers of the observed vegetation response. New hydrological insights for the region: During 1982–2016 we found a significant decrease (p < 0.05) in the sensitivity of vegetation productivity to water constraints in 26% of the Sahel-Sudan region, while 9% of the area showed a significantly increased sensitivity, mainly in the sub-humid zone. We further showed that CED significantly increased and decreased, respectively in around 9% of the study area in both cases. Our climatic driver attribution analysis suggested the existence of varying underlying mechanisms governing vegetation productivity in response to water deficit across the Sahel-Sudan dryland ecosystems. Our findings emphasize the need for diverse strategies in sustainable ecosystem management to effectively address these varying mechanisms.

AB - Study region: The Africa Sahel-Sudan region, defined by annual rainfall between 150 and 1200 mm. Study focus: Understanding the mechanism of vegetation response to water availability could help mitigate the potential adverse effects of climate change on global dryland ecosystems. In the Sahel-Sudan region, spatio-temporal changes and drivers of the vegetation-water response remain unclear. This study employs long-term satellite water and vegetation products as proxies of water availability and vegetation productivity to analyze changes in vegetation-water sensitivity and the cumulative effect duration (CED) representing a measure of the legacy effect of the impact of water constraints on vegetation. A random forest model was subsequently used to analyze potential climatic drivers of the observed vegetation response. New hydrological insights for the region: During 1982–2016 we found a significant decrease (p < 0.05) in the sensitivity of vegetation productivity to water constraints in 26% of the Sahel-Sudan region, while 9% of the area showed a significantly increased sensitivity, mainly in the sub-humid zone. We further showed that CED significantly increased and decreased, respectively in around 9% of the study area in both cases. Our climatic driver attribution analysis suggested the existence of varying underlying mechanisms governing vegetation productivity in response to water deficit across the Sahel-Sudan dryland ecosystems. Our findings emphasize the need for diverse strategies in sustainable ecosystem management to effectively address these varying mechanisms.

KW - Climate variability

KW - Cumulative effect duration

KW - Drylands

KW - Time series analysis

KW - Vegetation-water sensitivity

U2 - 10.1016/j.ejrh.2024.101672

DO - 10.1016/j.ejrh.2024.101672

M3 - Journal article

AN - SCOPUS:85183156129

VL - 52

JO - Journal of Hydrology: Regional Studies

JF - Journal of Hydrology: Regional Studies

SN - 2214-5818

M1 - 101672

ER -