Accumulation of soil carbon under elevated CO2 unaffected by warming and drought

Christiana A. Dietzen; Klaus Steenberg Larsen; Per L. Ambus; Anders Michelsen; Marie Frost Arndal; Claus Beier; Sabine Reinsch; Inger Kappel Schmidt

doi:10.1111/gcb.14699

Accumulation of soil carbon under elevated CO₂ unaffected by warming and drought

Christiana A. Dietzen^*, Klaus Steenberg Larsen, Per L. Ambus, Anders Michelsen, Marie Frost Arndal, Claus Beier, Sabine Reinsch, Inger Kappel Schmidt

^*Corresponding author for this work

5 Citations (Scopus)

Abstract

Elevated atmospheric CO₂ concentration and climate change may substantially alter soil carbon (C) dynamics, which in turn may impact future climate through feedback cycles. However, only very few field experiments worldwide have combined elevated CO₂ (eCO₂) with both warming and changes in precipitation in order to study the potential combined effects of changes in these fundamental drivers of C cycling in ecosystems. We exposed a temperate heath/grassland to eCO₂, warming, and drought, in all combinations for 8 years. At the end of the study, soil C stocks were on average 0.927 kg C/m² higher across all treatment combinations with eCO₂ compared to ambient CO₂ treatments (equal to an increase of 0.120 ± 0.043 kg C m⁻² year⁻¹), and showed no sign of slowed accumulation over time. However, if observed pretreatment differences in soil C are taken into account, the annual rate of increase caused by eCO₂ may be as high as 0.177 ± 0.070 kg C m⁻² year⁻¹. Furthermore, the response to eCO₂ was not affected by simultaneous exposure to warming and drought. The robust increase in soil C under eCO₂ observed here, even when combined with other climate change factors, suggests that there is continued and strong potential for enhanced soil carbon sequestration in some ecosystems to mitigate increasing atmospheric CO₂ concentrations under future climate conditions. The feedback between land C and climate remains one of the largest sources of uncertainty in future climate projections, yet experimental data under simulated future climate, and especially including combined changes, are still scarce. Globally coordinated and distributed experiments with long-term measurements of changes in soil C in response to the three major climate change-related global changes, eCO₂, warming, and changes in precipitation patterns, are, therefore, urgently needed.

Original language	English
Journal	Global Change Biology
Volume	25
Issue number	9
Pages (from-to)	2970-2977
Number of pages	8
ISSN	1354-1013
DOIs	https://doi.org/10.1111/gcb.14699
Publication status	Published - 2019

Keywords

climate driver interactions
drought
elevated CO
FACE
multifactor climate change experiment
soil carbon
warming

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

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10.1111/gcb.14699

Cite this

@article{bc67709d7e984914b33e4b52423928bd,

title = "Accumulation of soil carbon under elevated CO2 unaffected by warming and drought",

abstract = "Elevated atmospheric CO2 concentration and climate change may substantially alter soil carbon (C) dynamics, which in turn may impact future climate through feedback cycles. However, only very few field experiments worldwide have combined elevated CO2 (eCO2) with both warming and changes in precipitation in order to study the potential combined effects of changes in these fundamental drivers of C cycling in ecosystems. We exposed a temperate heath/grassland to eCO2, warming, and drought, in all combinations for 8 years. At the end of the study, soil C stocks were on average 0.927 kg C/m2 higher across all treatment combinations with eCO2 compared to ambient CO2 treatments (equal to an increase of 0.120 ± 0.043 kg C m−2 year−1), and showed no sign of slowed accumulation over time. However, if observed pretreatment differences in soil C are taken into account, the annual rate of increase caused by eCO2 may be as high as 0.177 ± 0.070 kg C m−2 year−1. Furthermore, the response to eCO2 was not affected by simultaneous exposure to warming and drought. The robust increase in soil C under eCO2 observed here, even when combined with other climate change factors, suggests that there is continued and strong potential for enhanced soil carbon sequestration in some ecosystems to mitigate increasing atmospheric CO2 concentrations under future climate conditions. The feedback between land C and climate remains one of the largest sources of uncertainty in future climate projections, yet experimental data under simulated future climate, and especially including combined changes, are still scarce. Globally coordinated and distributed experiments with long-term measurements of changes in soil C in response to the three major climate change-related global changes, eCO2, warming, and changes in precipitation patterns, are, therefore, urgently needed.",

keywords = "climate driver interactions, drought, elevated CO, FACE, multifactor climate change experiment, soil carbon, warming",

author = "Dietzen, {Christiana A.} and Larsen, {Klaus Steenberg} and Ambus, {Per L.} and Anders Michelsen and Arndal, {Marie Frost} and Claus Beier and Sabine Reinsch and Schmidt, {Inger Kappel}",

year = "2019",

doi = "10.1111/gcb.14699",

language = "English",

volume = "25",

pages = "2970--2977",

journal = "Global Change Biology",

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T1 - Accumulation of soil carbon under elevated CO2 unaffected by warming and drought

AU - Dietzen, Christiana A.

AU - Larsen, Klaus Steenberg

AU - Ambus, Per L.

AU - Michelsen, Anders

AU - Arndal, Marie Frost

AU - Beier, Claus

AU - Reinsch, Sabine

AU - Schmidt, Inger Kappel

PY - 2019

Y1 - 2019

N2 - Elevated atmospheric CO2 concentration and climate change may substantially alter soil carbon (C) dynamics, which in turn may impact future climate through feedback cycles. However, only very few field experiments worldwide have combined elevated CO2 (eCO2) with both warming and changes in precipitation in order to study the potential combined effects of changes in these fundamental drivers of C cycling in ecosystems. We exposed a temperate heath/grassland to eCO2, warming, and drought, in all combinations for 8 years. At the end of the study, soil C stocks were on average 0.927 kg C/m2 higher across all treatment combinations with eCO2 compared to ambient CO2 treatments (equal to an increase of 0.120 ± 0.043 kg C m−2 year−1), and showed no sign of slowed accumulation over time. However, if observed pretreatment differences in soil C are taken into account, the annual rate of increase caused by eCO2 may be as high as 0.177 ± 0.070 kg C m−2 year−1. Furthermore, the response to eCO2 was not affected by simultaneous exposure to warming and drought. The robust increase in soil C under eCO2 observed here, even when combined with other climate change factors, suggests that there is continued and strong potential for enhanced soil carbon sequestration in some ecosystems to mitigate increasing atmospheric CO2 concentrations under future climate conditions. The feedback between land C and climate remains one of the largest sources of uncertainty in future climate projections, yet experimental data under simulated future climate, and especially including combined changes, are still scarce. Globally coordinated and distributed experiments with long-term measurements of changes in soil C in response to the three major climate change-related global changes, eCO2, warming, and changes in precipitation patterns, are, therefore, urgently needed.

AB - Elevated atmospheric CO2 concentration and climate change may substantially alter soil carbon (C) dynamics, which in turn may impact future climate through feedback cycles. However, only very few field experiments worldwide have combined elevated CO2 (eCO2) with both warming and changes in precipitation in order to study the potential combined effects of changes in these fundamental drivers of C cycling in ecosystems. We exposed a temperate heath/grassland to eCO2, warming, and drought, in all combinations for 8 years. At the end of the study, soil C stocks were on average 0.927 kg C/m2 higher across all treatment combinations with eCO2 compared to ambient CO2 treatments (equal to an increase of 0.120 ± 0.043 kg C m−2 year−1), and showed no sign of slowed accumulation over time. However, if observed pretreatment differences in soil C are taken into account, the annual rate of increase caused by eCO2 may be as high as 0.177 ± 0.070 kg C m−2 year−1. Furthermore, the response to eCO2 was not affected by simultaneous exposure to warming and drought. The robust increase in soil C under eCO2 observed here, even when combined with other climate change factors, suggests that there is continued and strong potential for enhanced soil carbon sequestration in some ecosystems to mitigate increasing atmospheric CO2 concentrations under future climate conditions. The feedback between land C and climate remains one of the largest sources of uncertainty in future climate projections, yet experimental data under simulated future climate, and especially including combined changes, are still scarce. Globally coordinated and distributed experiments with long-term measurements of changes in soil C in response to the three major climate change-related global changes, eCO2, warming, and changes in precipitation patterns, are, therefore, urgently needed.

KW - climate driver interactions

KW - drought

KW - elevated CO

KW - FACE

KW - multifactor climate change experiment

KW - soil carbon

KW - warming

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DO - 10.1111/gcb.14699

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SP - 2970

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JO - Global Change Biology

JF - Global Change Biology

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