Dataset Information

The impact of soil microorganisms on the global budget of delta18O in atmospheric CO2.

ABSTRACT: Improved global estimates of terrestrial photosynthesis and respiration are critical for predicting the rate of change in atmospheric CO(2). The oxygen isotopic composition of atmospheric CO(2) can be used to estimate these fluxes because oxygen isotopic exchange between CO(2) and water creates distinct isotopic flux signatures. The enzyme carbonic anhydrase (CA) is known to accelerate this exchange in leaves, but the possibility of CA activity in soils is commonly neglected. Here, we report widespread accelerated soil CO(2) hydration. Exchange was 10-300 times faster than the uncatalyzed rate, consistent with typical population sizes for CA-containing soil microorganisms. Including accelerated soil hydration in global model simulations modifies contributions from soil and foliage to the global CO(18)O budget and eliminates persistent discrepancies existing between model and atmospheric observations. This enhanced soil hydration also increases the differences between the isotopic signatures of photosynthesis and respiration, particularly in the tropics, increasing the precision of CO(2) gross fluxes obtained by using the delta(18)O of atmospheric CO(2) by 50%.

SUBMITTER: Wingate L

PROVIDER: S-EPMC2799687 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature

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The impact of soil microorganisms on the global budget of delta18O in atmospheric CO2.

Wingate Lisa L Ogée Jérôme J Cuntz Matthias M Genty Bernard B Reiter Ilja I Seibt Ulli U Yakir Dan D Maseyk Kadmiel K Pendall Elise G EG Barbour Margaret M MM Mortazavi Behzad B Burlett Régis R Peylin Philippe P Miller John J Mencuccini Maurizio M Shim Jee H JH Hunt John J Grace John J

Proceedings of the National Academy of Sciences of the United States of America 20091215 52

Improved global estimates of terrestrial photosynthesis and respiration are critical for predicting the rate of change in atmospheric CO(2). The oxygen isotopic composition of atmospheric CO(2) can be used to estimate these fluxes because oxygen isotopic exchange between CO(2) and water creates distinct isotopic flux signatures. The enzyme carbonic anhydrase (CA) is known to accelerate this exchange in leaves, but the possibility of CA activity in soils is commonly neglected. Here, we report wid ...[more]

PMID: 20018776

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Dataset Information

The impact of soil microorganisms on the global budget of delta18O in atmospheric CO2.

Publications

The impact of soil microorganisms on the global budget of delta18O in atmospheric CO2.

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