Mechanistic drivers of stem respiration: A modelling exercise across species and seasons.
Plant Cell Environ
; 45(4): 1270-1285, 2022 04.
Article
en En
| MEDLINE
| ID: mdl-34914118
ABSTRACT
Stem respiration (RS ) plays a crucial role in plant carbon budgets. However, its poor understanding limits our ability to model woody tissue and whole-tree respiration. A biophysical model of stem water and carbon fluxes (TReSpire) was calibrated on cedar, maple and oak trees during spring and late summer. For this, stem sap flow, water potential, diameter variation, temperature, CO2 efflux, allometry and biochemistry were monitored. Shoot photosynthesis (PN ) and nonstructural carbohydrates (NSC) were additionally measured to evaluate source-sink relations. The highest RS and stem growth was found in maple and oak during spring, both being seasonally decoupled from PN and [NSC]. Temperature largely affected maintenance respiration (RM ) in the short term, but temperature-normalized RM was highly variable on a seasonal timescale. Overall, most of the respired CO2 radially diffused to the atmosphere (>87%) while the remainder was transported upward with the transpiration stream. The modelling exercise highlights the sink-driven behaviour of RS and the significance of overall metabolic activity on nitrogen (N) allocation patterns and N-normalized respiratory costs to capture RS variability over the long term. These insights should be considered when modelling plant respiration, whose representation is currently biased towards a better understanding of leaf metabolism.
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Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Acer
/
Xilema
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Plant Cell Environ
Asunto de la revista:
BOTANICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Bélgica