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Tracing carbon and oxygen isotope signals from newly assimilated sugars in the leaves to the tree‐ring archive
Author(s) -
GESSLER ARTHUR,
BRANDES ELKE,
BUCHMANN NINA,
HELLE GERHARD,
RENNENBERG HEINZ,
BARNARD ROMAIN L.
Publication year - 2009
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2009.01957.x
Subject(s) - phloem , delta , xylem , isotopes of carbon , isotopes of oxygen , oxygen , photosynthesis , stable isotope ratio , chemistry , botany , δ13c , dendrochronology , isotope , carbon fibers , environmental chemistry , ecology , total organic carbon , biology , paleontology , physics , materials science , organic chemistry , quantum mechanics , nuclear chemistry , composite number , engineering , aerospace engineering , composite material
The analysis of δ 13 C and δ 18 O in tree‐ring archives offers retrospective insights into environmental conditions and ecophysiological processes. While photosynthetic carbon isotope discrimination and evaporative oxygen isotope enrichment are well understood, we lack information on how the isotope signal is altered by downstream metabolic processes. In Pinus sylvestris , we traced the isotopic signals from their origin in the leaf water ( δ 18 O) or the newly assimilated carbon ( δ 13 C), via phloem sugars to the tree‐ring, over a time‐scale that ranges from hours to a growing season. Seasonally, variable 13 C enrichment of sugars related to phloem loading and transport did lead to uncoupling between δ 13 C in the tree‐ring, and the c i / c a ratio at the leaf level. In contrast, the oxygen isotope signal was transferred from the leaf water to the tree‐ring with an expected enrichment of 27‰, with time‐lags of approximately 2 weeks and with a 40% exchange between organic oxygen and xylem water oxygen during cellulose synthesis. This integrated overview of the fate of carbon and oxygen isotope signals within the model tree species P. sylvestris provides a novel physiological basis for the interpretation of δ 13 C and δ 18 O in tree‐ring ecology.