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Titel |
Quantifying uncertainties in soil carbon responses to changes in global mean temperature and precipitation |
VerfasserIn |
K. Nishina, A. Ito, D. J. Beerling, P. Cadule, P. Ciais, D. B. Clark, P. Falloon, A. D. Friend, R. Kahana, E. Kato, R. Keribin, W. Lucht, M. Lomas, T. T. Rademacher, R. Pavlick, S. Schaphoff, N. Vuichard, L. Warszawaski, T. Yokohata |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
2190-4979
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Digitales Dokument |
URL |
Erschienen |
In: Earth System Dynamics ; 5, no. 1 ; Nr. 5, no. 1 (2014-04-02), S.197-209 |
Datensatznummer |
250115301
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Publikation (Nr.) |
copernicus.org/esd-5-197-2014.pdf |
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Zusammenfassung |
Soil organic carbon (SOC) is the largest carbon pool in terrestrial
ecosystems and may play a key role in biospheric feedbacks with elevated
atmospheric carbon dioxide (CO2) in a warmer future world. We examined the
simulation results of seven terrestrial biome models when forced with climate
projections from four representative-concentration-pathways (RCPs)-based
atmospheric concentration scenarios. The goal was to specify calculated
uncertainty in global SOC stock projections from global and regional
perspectives and give insight to the improvement of SOC-relevant processes in
biome models. SOC stocks among the biome models varied from 1090 to
2650 Pg C even in historical periods (ca. 2000). In a higher forcing
scenario (i.e., RCP8.5), inconsistent estimates of impact on the total SOC
(2099–2000) were obtained from different biome model simulations, ranging
from a net sink of 347 Pg C to a net source of 122 Pg C. In all models,
the increasing atmospheric CO2 concentration in the RCP8.5 scenario
considerably contributed to carbon accumulation in SOC. However, magnitudes
varied from 93 to 264 Pg C by the end of the 21st century across biome
models. Using the time-series data of total global SOC simulated by each
biome model, we analyzed the sensitivity of the global SOC stock to global
mean temperature and global precipitation anomalies (ΔT and
ΔP respectively) in each biome model using a state-space model. This analysis
suggests that ΔT explained global SOC stock changes in most models
with a resolution of 1–2 °C, and the magnitude of global SOC
decomposition from a 2 °C rise ranged from almost 0
to 3.53 Pg C yr−1 among the biome models. However,
ΔP had a negligible impact on change in the global SOC changes.
Spatial heterogeneity was evident and inconsistent among the biome models,
especially in boreal to arctic regions. Our study reveals considerable
climate uncertainty in SOC decomposition responses to climate and CO2 change
among biome models. Further research is required to improve our ability to
estimate biospheric feedbacks through both SOC-relevant and
vegetation-relevant processes. |
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