Spatiotemporal variability in carbon exchange fluxes across the Sahel

Håkan Torbern Tagesson; Rasmus Fensholt; Bernard Cappelaere; Eric Mougin; Stéphanie Marie Anne F Horion; Laurent Kergoat; Hector Nieto Solana; Cheikh Mbow; Andrea Ehammer; Jérôme Demarty; Jonas Ardö

doi:10.1016/j.agrformet.2016.05.013

Spatiotemporal variability in carbon exchange fluxes across the Sahel

Håkan Torbern Tagesson^*, Rasmus Fensholt, Bernard Cappelaere, Eric Mougin, Stéphanie Marie Anne F Horion, Laurent Kergoat, Hector Nieto Solana, Cheikh Mbow, Andrea Ehammer, Jérôme Demarty, Jonas Ardö

^*Corresponding author for this work

Geography

21 Citations (Scopus)

Abstract

Semi-arid regions play an increasingly important role as a sink within the global carbon (C) cycle and is the main biome driving inter-annual variability in carbon dioxide (CO₂) uptake by terrestrial ecosystems. This indicates the need for detailed studies of spatiotemporal variability in C cycling for semi-arid ecosystems. We have synthesized data on the land-atmosphere exchange of CO₂ measured with the eddy covariance technique from the six existing sites across the Sahel, one of the largest semi-arid regions in the world. The overall aim of the study is to analyse and quantify the spatiotemporal variability in these fluxes and to analyse to which degree spatiotemporal variation can be explained by hydrological, climatic, edaphic and vegetation variables. All ecosystems were C sinks (average ± total error -162 ± 48 g C m^-2 y^-1), but were smaller when strongly impacted by anthropogenic influences. Spatial and inter-annual variability in the C flux processes indicated a strong resilience to dry conditions, and were correlated with phenological metrics. Gross primary productivity (GPP) was the most important flux process affecting the sink strength, and diurnal variability in GPP was regulated by incoming radiation, whereas seasonal dynamics was closely coupled with phenology, and soil water content. Diurnal variability in ecosystem respiration was regulated by GPP, whereas seasonal variability was strongly coupled to phenology and GPP. A budget for the entire Sahel indicated a strong C sink mitigating the global anthropogenic C emissions. Global circulation models project an increase in temperature, whereas rainfall is projected to decrease for western Sahel and increase for the eastern part, indicating that the C sink will possibly decrease and increase for the western and eastern Sahel, respectively.

Original language	English
Journal	Agricultural and Forest Meteorology
Volume	226-227
Pages (from-to)	108-118
Number of pages	11
ISSN	0168-1923
DOIs	https://doi.org/10.1016/j.agrformet.2016.05.013
Publication status	Published - 2016

Keywords

Carbon dioxide
Climate change
Dryland
Net ecosystem exchange
Photosynthesis
Respiration

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.agrformet.2016.05.013

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@article{e59548f3d355464aaba5d076c3a22453,

title = "Spatiotemporal variability in carbon exchange fluxes across the Sahel",

abstract = "Semi-arid regions play an increasingly important role as a sink within the global carbon (C) cycle and is the main biome driving inter-annual variability in carbon dioxide (CO2) uptake by terrestrial ecosystems. This indicates the need for detailed studies of spatiotemporal variability in C cycling for semi-arid ecosystems. We have synthesized data on the land-atmosphere exchange of CO2 measured with the eddy covariance technique from the six existing sites across the Sahel, one of the largest semi-arid regions in the world. The overall aim of the study is to analyse and quantify the spatiotemporal variability in these fluxes and to analyse to which degree spatiotemporal variation can be explained by hydrological, climatic, edaphic and vegetation variables. All ecosystems were C sinks (average ± total error -162 ± 48 g C m-2 y-1), but were smaller when strongly impacted by anthropogenic influences. Spatial and inter-annual variability in the C flux processes indicated a strong resilience to dry conditions, and were correlated with phenological metrics. Gross primary productivity (GPP) was the most important flux process affecting the sink strength, and diurnal variability in GPP was regulated by incoming radiation, whereas seasonal dynamics was closely coupled with phenology, and soil water content. Diurnal variability in ecosystem respiration was regulated by GPP, whereas seasonal variability was strongly coupled to phenology and GPP. A budget for the entire Sahel indicated a strong C sink mitigating the global anthropogenic C emissions. Global circulation models project an increase in temperature, whereas rainfall is projected to decrease for western Sahel and increase for the eastern part, indicating that the C sink will possibly decrease and increase for the western and eastern Sahel, respectively.",

keywords = "Carbon dioxide, Climate change, Dryland, Net ecosystem exchange, Photosynthesis, Respiration",

author = "Tagesson, {H{\aa}kan Torbern} and Rasmus Fensholt and Bernard Cappelaere and Eric Mougin and Horion, {St{\'e}phanie Marie Anne F} and Laurent Kergoat and {Nieto Solana}, Hector and Cheikh Mbow and Andrea Ehammer and J{\'e}r{\^o}me Demarty and Jonas Ard{\"o}",

year = "2016",

doi = "10.1016/j.agrformet.2016.05.013",

language = "English",

volume = "226-227",

pages = "108--118",

journal = "Agricultural and Forest Meteorology",

issn = "0168-1923",

publisher = "Elsevier",

}

TY - JOUR

T1 - Spatiotemporal variability in carbon exchange fluxes across the Sahel

AU - Tagesson, Håkan Torbern

AU - Fensholt, Rasmus

AU - Cappelaere, Bernard

AU - Mougin, Eric

AU - Horion, Stéphanie Marie Anne F

AU - Kergoat, Laurent

AU - Nieto Solana, Hector

AU - Mbow, Cheikh

AU - Ehammer, Andrea

AU - Demarty, Jérôme

AU - Ardö, Jonas

PY - 2016

Y1 - 2016

N2 - Semi-arid regions play an increasingly important role as a sink within the global carbon (C) cycle and is the main biome driving inter-annual variability in carbon dioxide (CO2) uptake by terrestrial ecosystems. This indicates the need for detailed studies of spatiotemporal variability in C cycling for semi-arid ecosystems. We have synthesized data on the land-atmosphere exchange of CO2 measured with the eddy covariance technique from the six existing sites across the Sahel, one of the largest semi-arid regions in the world. The overall aim of the study is to analyse and quantify the spatiotemporal variability in these fluxes and to analyse to which degree spatiotemporal variation can be explained by hydrological, climatic, edaphic and vegetation variables. All ecosystems were C sinks (average ± total error -162 ± 48 g C m-2 y-1), but were smaller when strongly impacted by anthropogenic influences. Spatial and inter-annual variability in the C flux processes indicated a strong resilience to dry conditions, and were correlated with phenological metrics. Gross primary productivity (GPP) was the most important flux process affecting the sink strength, and diurnal variability in GPP was regulated by incoming radiation, whereas seasonal dynamics was closely coupled with phenology, and soil water content. Diurnal variability in ecosystem respiration was regulated by GPP, whereas seasonal variability was strongly coupled to phenology and GPP. A budget for the entire Sahel indicated a strong C sink mitigating the global anthropogenic C emissions. Global circulation models project an increase in temperature, whereas rainfall is projected to decrease for western Sahel and increase for the eastern part, indicating that the C sink will possibly decrease and increase for the western and eastern Sahel, respectively.

AB - Semi-arid regions play an increasingly important role as a sink within the global carbon (C) cycle and is the main biome driving inter-annual variability in carbon dioxide (CO2) uptake by terrestrial ecosystems. This indicates the need for detailed studies of spatiotemporal variability in C cycling for semi-arid ecosystems. We have synthesized data on the land-atmosphere exchange of CO2 measured with the eddy covariance technique from the six existing sites across the Sahel, one of the largest semi-arid regions in the world. The overall aim of the study is to analyse and quantify the spatiotemporal variability in these fluxes and to analyse to which degree spatiotemporal variation can be explained by hydrological, climatic, edaphic and vegetation variables. All ecosystems were C sinks (average ± total error -162 ± 48 g C m-2 y-1), but were smaller when strongly impacted by anthropogenic influences. Spatial and inter-annual variability in the C flux processes indicated a strong resilience to dry conditions, and were correlated with phenological metrics. Gross primary productivity (GPP) was the most important flux process affecting the sink strength, and diurnal variability in GPP was regulated by incoming radiation, whereas seasonal dynamics was closely coupled with phenology, and soil water content. Diurnal variability in ecosystem respiration was regulated by GPP, whereas seasonal variability was strongly coupled to phenology and GPP. A budget for the entire Sahel indicated a strong C sink mitigating the global anthropogenic C emissions. Global circulation models project an increase in temperature, whereas rainfall is projected to decrease for western Sahel and increase for the eastern part, indicating that the C sink will possibly decrease and increase for the western and eastern Sahel, respectively.

KW - Carbon dioxide

KW - Climate change

KW - Dryland

KW - Net ecosystem exchange

KW - Photosynthesis

KW - Respiration

U2 - 10.1016/j.agrformet.2016.05.013

DO - 10.1016/j.agrformet.2016.05.013

M3 - Journal article

AN - SCOPUS:84975452626

SN - 0168-1923

VL - 226-227

SP - 108

EP - 118

JO - Agricultural and Forest Meteorology

JF - Agricultural and Forest Meteorology

ER -

Spatiotemporal variability in carbon exchange fluxes across the Sahel

Abstract

Keywords

UN SDGs

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