Does photosynthesis affect grassland soil-respired CO2 and its carbon isotope composition on a diurnal timescale?
Soil respiration is the largest flux of carbon (C) from terrestrial ecosystems to the atmosphere. Here, we tested the hypothesis that photosynthesis affects the diurnal pattern of grassland soil-respired CO(2) and its C isotope composition (delta(13)C(SR)). A combined shading and pulse-labelling exp...
| Veröffentlicht in: | The New phytologist. - 1979. - 182(2009), 2 vom: 01., Seite 451-460 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2009
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Carbon Isotopes Soil Carbon Dioxide 142M471B3J Carbon 7440-44-0 |
| Zusammenfassung: | Soil respiration is the largest flux of carbon (C) from terrestrial ecosystems to the atmosphere. Here, we tested the hypothesis that photosynthesis affects the diurnal pattern of grassland soil-respired CO(2) and its C isotope composition (delta(13)C(SR)). A combined shading and pulse-labelling experiment was carried out in a mountain grassland. delta(13)C(SR) was monitored at a high time resolution with a tunable diode laser absorption spectrometer. In unlabelled plots a diurnal pattern of delta(13)C(SR) was observed, which was not explained by soil temperature, moisture or flux rates and contained a component that was also independent of assimilate supply. In labelled plots delta(13)C(SR) reflected a rapid transfer and respiratory use of freshly plant-assimilated C and a diurnal shift in the predominant respiratory C source from recent (i.e. at least 1 d old) to fresh (i.e. photoassimilates produced on the same day). We conclude that in grasslands the plant-derived substrates used for soil respiratory processes vary during the day, and that photosynthesis provides an important and immediate C source. These findings indicate a tight coupling in the plant-soil system and the importance of plant metabolism for soil CO(2) fluxes |
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| Beschreibung: | Date Completed 17.07.2009 Date Revised 22.03.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/j.1469-8137.2008.02755.x |