Drivers of intra-seasonal δ13 C signal in tree-rings of Pinus sylvestris as indicated by compound-specific and laser ablation isotope analysis.
Plant Cell Environ
; 46(9): 2649-2666, 2023 09.
Article
en En
| MEDLINE
| ID: mdl-37312624
ABSTRACT
Carbon isotope composition of tree-ring (δ13 CRing ) is a commonly used proxy for environmental change and ecophysiology. δ13 CRing reconstructions are based on a solid knowledge of isotope fractionations during formation of primary photosynthates (δ13 CP ), such as sucrose. However, δ13 CRing is not merely a record of δ13 CP . Isotope fractionation processes, which are not yet fully understood, modify δ13 CP during sucrose transport. We traced, how the environmental intra-seasonal δ13 CP signal changes from leaves to phloem, tree-ring and roots, for 7 year old Pinus sylvestris, using δ13 C analysis of individual carbohydrates, δ13 CRing laser ablation, leaf gas exchange and enzyme activity measurements. The intra-seasonal δ13 CP dynamics was clearly reflected by δ13 CRing , suggesting negligible impact of reserve use on δ13 CRing . However, δ13 CP became increasingly 13 C-enriched during down-stem transport, probably due to post-photosynthetic fractionations such as sink organ catabolism. In contrast, δ13 C of water-soluble carbohydrates, analysed for the same extracts, did not reflect the same isotope dynamics and fractionations as δ13 CP , but recorded intra-seasonal δ13 CP variability. The impact of environmental signals on δ13 CRing , and the 0.5 and 1.7 depletion in photosynthates compared ring organic matter and tree-ring cellulose, respectively, are useful pieces of information for studies exploiting δ13 CRing .
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Pinus
/
Pinus sylvestris
/
Terapia por Láser
Idioma:
En
Revista:
Plant Cell Environ
Asunto de la revista:
BOTANICA
Año:
2023
Tipo del documento:
Article
País de afiliación:
Finlandia