Back to Search
Start Over
Autotrophic respiration modulates the carbon isotope composition of soil respiration in a mixed forest.
- Source :
-
The Science of the total environment [Sci Total Environ] 2022 Feb 10; Vol. 807 (Pt 2), pp. 150834. Date of Electronic Publication: 2021 Oct 07. - Publication Year :
- 2022
-
Abstract
- Carbon isotopic composition of soil respired CO <subscript>2</subscript> (soil δ <superscript>13</superscript> C <subscript>R</subscript> ) has been regarded as a good indicator of the linkages between aboveground processes and soil respiration. However, whether δ <superscript>13</superscript> C <subscript>R</subscript> of autotrophic or heterotrophic component of soil respiration dominates the temporal variability of total soil δ <superscript>13</superscript> C <subscript>R</subscript> was rarely examined by previous studies. In this study, carbon isotopic composition of atmospheric CO <subscript>2</subscript> (δ <superscript>13</superscript> C <subscript>air</subscript> ) and soil δ <superscript>13</superscript> C <subscript>R</subscript> in control (with roots) and trenched (without roots) plots were measured in a temperated mixed forest. A <superscript>13</superscript> C isotopic profile system and an automated soil respiration system were used for δ <superscript>13</superscript> C <subscript>air</subscript> and soil δ <superscript>13</superscript> C <subscript>R</subscript> measurements, respectively. We found that soil δ <superscript>13</superscript> C <subscript>R</subscript> in the control plots changed substantially in the growing season and it was more negative (by ~0.6‰) than that in the trenched plots, while soil δ <superscript>13</superscript> C <subscript>R</subscript> in the trenched plots showed a minor temporal variability. This suggests that δ <superscript>13</superscript> C <subscript>R</subscript> from the autotrophic respiration is the key decider of the seasonal variation pattern of the soil δ <superscript>13</superscript> C <subscript>R</subscript> . Moreover, the seasonal variation of soil δ <superscript>13</superscript> C <subscript>R</subscript> in the control plots showed a similar pattern with the seasonal variation of δ <superscript>13</superscript> C <subscript>air</subscript> . A significant time-lag was found between δ <superscript>13</superscript> C <subscript>air</subscript> and soil δ <superscript>13</superscript> C <subscript>R</subscript> , showing that soil δ <superscript>13</superscript> C <subscript>R</subscript> generally lagged behind δ <superscript>13</superscript> C <subscript>air</subscript> 15 days. This result supports the hypothesis that soil respiration is closely related to carbon assimilation at the leaf-level and also stressed the importance of δ <superscript>13</superscript> C <subscript>air</subscript> in shaping soil δ <superscript>13</superscript> C <subscript>R</subscript> . These findings are highly valuable to develop the process-based models of the carbon cycle of forest ecosystems.<br />Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br /> (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Subjects :
- Carbon Cycle
Carbon Isotopes
Forests
Ecosystem
Soil
Subjects
Details
- Language :
- English
- ISSN :
- 1879-1026
- Volume :
- 807
- Issue :
- Pt 2
- Database :
- MEDLINE
- Journal :
- The Science of the total environment
- Publication Type :
- Academic Journal
- Accession number :
- 34627921
- Full Text :
- https://doi.org/10.1016/j.scitotenv.2021.150834