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Isotope ratio laser spectroscopy to disentangle xylem-transported from locally respired CO2 in stem CO2 efflux
- Source :
- Tree Physiology. 39:819-830
- Publication Year :
- 2019
- Publisher :
- Oxford University Press (OUP), 2019.
-
Abstract
- Respired CO2 in woody tissues radially diffuses to the atmosphere or it is transported upward with the transpiration stream, making the origin of CO2 in stem CO2 efflux (EA) uncertain, which may confound stem respiration (RS) estimates. An aqueous 13C-enriched solution was infused into stems of Populus tremula L. trees, and real-time measurements of 13C-CO2 and 12C-CO2 in EA were performed via Cavity Ring Down Laser Spectroscopy (CRDS). The contribution of locally respired CO2 (LCO2) and xylem-transported CO2 (TCO2) to EA was estimated from their different isotopic composition. Mean daily values of TCO2/EA ranged from 13% to 38%, evidencing the notable role that xylem CO2 transport plays in the assessment of stem respiration. Mean daily TCO2/EA did not differ between treatments of drought stress and light exclusion of woody tissues, but they showed different TCO2/EA dynamics on a sub-daily time scale. Sub-daily CO2 diffusion patterns were explained by a light-induced axial CO2 gradient ascribed to woody tissue photosynthesis, and the resistance to radial CO2 diffusion determined by bark water content. Here, we demonstrate the outstanding potential of CRDS paired with 13C-CO2 labelling to advance in the understanding of CO2 movement at the plant-atmosphere interface and the respiratory physiology in woody tissues.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Physiology
Diffusion
Co2 efflux
Plant Science
Photosynthesis
01 natural sciences
Trees
03 medical and health sciences
chemistry.chemical_compound
Isotopes
Xylem
Respiration
Spectroscopy
Water content
Isotope
Plant Stems
Chemistry
Spectrum Analysis
Radiochemistry
Botany
Plant Transpiration
Carbon Dioxide
Populus
030104 developmental biology
visual_art
Transpiration stream
Carbon dioxide
Biophysics
visual_art.visual_art_medium
Bark
010606 plant biology & botany
Subjects
Details
- ISSN :
- 17584469
- Volume :
- 39
- Database :
- OpenAIRE
- Journal :
- Tree Physiology
- Accession number :
- edsair.doi.dedup.....fefce4420119086856a45413015920dd