Elevated CO2 and temperature increase soil C losses from a soybean–maize ecosystem

Christopher K. Black, Sarah C. Davis, Tara W. Hudiburg, Carl J. Bernacchi, Evan H. DeLucia

Research output: Contribution to journalArticle

Abstract

Warming temperatures and increasing CO2 are likely to have large effects on the amount of carbon stored in soil, but predictions of these effects are poorly constrained. We elevated temperature (canopy: +2.8 °C; soil growing season: +1.8 °C; soil fallow: +2.3 °C) for 3 years within the 9th–11th years of an elevated CO2 (+200 ppm) experiment on a maize–soybean agroecosystem, measured respiration by roots and soil microbes, and then used a process-based ecosystem model (DayCent) to simulate the decadal effects of warming and CO2 enrichment on soil C. Both heating and elevated CO2 increased respiration from soil microbes by ~20%, but heating reduced respiration from roots and rhizosphere by ~25%. The effects were additive, with no heat × CO2 interactions. Particulate organic matter and total soil C declined over time in all treatments and were lower in elevated CO2 plots than in ambient plots, but did not differ between heat treatments. We speculate that these declines indicate a priming effect, with increased C inputs under elevated CO2 fueling a loss of old soil carbon. Model simulations of heated plots agreed with our observations and predicted loss of ~15% of soil organic C after 100 years of heating, but simulations of elevated CO2 failed to predict the observed C losses and instead predicted a ~4% gain in soil organic C under any heating conditions. Despite model uncertainty, our empirical results suggest that combined, elevated CO2 and temperature will lead to long-term declines in the amount of carbon stored in agricultural soils.

Original languageEnglish (US)
Pages (from-to)435-445
Number of pages11
JournalGlobal change biology
Volume23
Issue number1
DOIs
StatePublished - Jan 1 2017

Fingerprint

Ecosystems
Soils
ecosystem
soil
heating
temperature
respiration
Temperature
organic soil
Heating
warming
Carbon
carbon
agricultural ecosystem
particulate organic matter
loss
soil carbon
fallow
agricultural soil
simulation

Keywords

  • DayCent
  • climate change
  • priming
  • soil respiration
  • soybean free-air concentration enrichment
  • warming

ASJC Scopus subject areas

  • Global and Planetary Change
  • Environmental Chemistry
  • Ecology
  • Environmental Science(all)

Cite this

Elevated CO2 and temperature increase soil C losses from a soybean–maize ecosystem. / Black, Christopher K.; Davis, Sarah C.; Hudiburg, Tara W.; Bernacchi, Carl J.; DeLucia, Evan H.

In: Global change biology, Vol. 23, No. 1, 01.01.2017, p. 435-445.

Research output: Contribution to journalArticle

Black, Christopher K. ; Davis, Sarah C. ; Hudiburg, Tara W. ; Bernacchi, Carl J. ; DeLucia, Evan H. / Elevated CO2 and temperature increase soil C losses from a soybean–maize ecosystem. In: Global change biology. 2017 ; Vol. 23, No. 1. pp. 435-445.
@article{7db70adbcafa41b5a13b102719f04713,
title = "Elevated CO2 and temperature increase soil C losses from a soybean–maize ecosystem",
abstract = "Warming temperatures and increasing CO2 are likely to have large effects on the amount of carbon stored in soil, but predictions of these effects are poorly constrained. We elevated temperature (canopy: +2.8 °C; soil growing season: +1.8 °C; soil fallow: +2.3 °C) for 3 years within the 9th–11th years of an elevated CO2 (+200 ppm) experiment on a maize–soybean agroecosystem, measured respiration by roots and soil microbes, and then used a process-based ecosystem model (DayCent) to simulate the decadal effects of warming and CO2 enrichment on soil C. Both heating and elevated CO2 increased respiration from soil microbes by ~20{\%}, but heating reduced respiration from roots and rhizosphere by ~25{\%}. The effects were additive, with no heat × CO2 interactions. Particulate organic matter and total soil C declined over time in all treatments and were lower in elevated CO2 plots than in ambient plots, but did not differ between heat treatments. We speculate that these declines indicate a priming effect, with increased C inputs under elevated CO2 fueling a loss of old soil carbon. Model simulations of heated plots agreed with our observations and predicted loss of ~15{\%} of soil organic C after 100 years of heating, but simulations of elevated CO2 failed to predict the observed C losses and instead predicted a ~4{\%} gain in soil organic C under any heating conditions. Despite model uncertainty, our empirical results suggest that combined, elevated CO2 and temperature will lead to long-term declines in the amount of carbon stored in agricultural soils.",
keywords = "DayCent, climate change, priming, soil respiration, soybean free-air concentration enrichment, warming",
author = "Black, {Christopher K.} and Davis, {Sarah C.} and Hudiburg, {Tara W.} and Bernacchi, {Carl J.} and DeLucia, {Evan H.}",
year = "2017",
month = "1",
day = "1",
doi = "10.1111/gcb.13378",
language = "English (US)",
volume = "23",
pages = "435--445",
journal = "Global Change Biology",
issn = "1354-1013",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Elevated CO2 and temperature increase soil C losses from a soybean–maize ecosystem

AU - Black, Christopher K.

AU - Davis, Sarah C.

AU - Hudiburg, Tara W.

AU - Bernacchi, Carl J.

AU - DeLucia, Evan H.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - Warming temperatures and increasing CO2 are likely to have large effects on the amount of carbon stored in soil, but predictions of these effects are poorly constrained. We elevated temperature (canopy: +2.8 °C; soil growing season: +1.8 °C; soil fallow: +2.3 °C) for 3 years within the 9th–11th years of an elevated CO2 (+200 ppm) experiment on a maize–soybean agroecosystem, measured respiration by roots and soil microbes, and then used a process-based ecosystem model (DayCent) to simulate the decadal effects of warming and CO2 enrichment on soil C. Both heating and elevated CO2 increased respiration from soil microbes by ~20%, but heating reduced respiration from roots and rhizosphere by ~25%. The effects were additive, with no heat × CO2 interactions. Particulate organic matter and total soil C declined over time in all treatments and were lower in elevated CO2 plots than in ambient plots, but did not differ between heat treatments. We speculate that these declines indicate a priming effect, with increased C inputs under elevated CO2 fueling a loss of old soil carbon. Model simulations of heated plots agreed with our observations and predicted loss of ~15% of soil organic C after 100 years of heating, but simulations of elevated CO2 failed to predict the observed C losses and instead predicted a ~4% gain in soil organic C under any heating conditions. Despite model uncertainty, our empirical results suggest that combined, elevated CO2 and temperature will lead to long-term declines in the amount of carbon stored in agricultural soils.

AB - Warming temperatures and increasing CO2 are likely to have large effects on the amount of carbon stored in soil, but predictions of these effects are poorly constrained. We elevated temperature (canopy: +2.8 °C; soil growing season: +1.8 °C; soil fallow: +2.3 °C) for 3 years within the 9th–11th years of an elevated CO2 (+200 ppm) experiment on a maize–soybean agroecosystem, measured respiration by roots and soil microbes, and then used a process-based ecosystem model (DayCent) to simulate the decadal effects of warming and CO2 enrichment on soil C. Both heating and elevated CO2 increased respiration from soil microbes by ~20%, but heating reduced respiration from roots and rhizosphere by ~25%. The effects were additive, with no heat × CO2 interactions. Particulate organic matter and total soil C declined over time in all treatments and were lower in elevated CO2 plots than in ambient plots, but did not differ between heat treatments. We speculate that these declines indicate a priming effect, with increased C inputs under elevated CO2 fueling a loss of old soil carbon. Model simulations of heated plots agreed with our observations and predicted loss of ~15% of soil organic C after 100 years of heating, but simulations of elevated CO2 failed to predict the observed C losses and instead predicted a ~4% gain in soil organic C under any heating conditions. Despite model uncertainty, our empirical results suggest that combined, elevated CO2 and temperature will lead to long-term declines in the amount of carbon stored in agricultural soils.

KW - DayCent

KW - climate change

KW - priming

KW - soil respiration

KW - soybean free-air concentration enrichment

KW - warming

UR - http://www.scopus.com/inward/record.url?scp=84978101099&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84978101099&partnerID=8YFLogxK

U2 - 10.1111/gcb.13378

DO - 10.1111/gcb.13378

M3 - Article

C2 - 27252041

AN - SCOPUS:84978101099

VL - 23

SP - 435

EP - 445

JO - Global Change Biology

JF - Global Change Biology

SN - 1354-1013

IS - 1

ER -