Rapid response of tree cellulose radiocarbon content to changes in atmospheric ¹⁴CO₂ concentration

Abstract

A detailed radial profile for the I4C concentration in tree stem cellulose, covering growth rings for the years 1962-1964, was obtained for a Sitka spruce of the US Pacific Coast using accelerator mass spectrometry. The tree cellulose I4C closely follows atmospheric I4CO2 concentrations, responding to changes with an apparent delay of 5 to 6 weeks. The delay in response is mostly due to the addition of between 13% and 28% of biospheric C 0 2 to the canopy-air C 0 2 used by the tree for stem cellulose. Delayed incorporation and the use of stored photosynthate of the previous fall appear less important. W 1 0

14C Activity in Different Sections and Chemical Fractions of Oak Tree Rings, AD 1938–1981

“…The total growing period is normally from June to the end of August. We see no clear evidence for any delay between the atmosphere and the CELL and INS fraction activity on a time scale of weeks, as earlier reported by Grootes et al (1989). We observe a memory effect in the early wood during the years, 1962-1963, with significantly lower activity than in the atmosphere.…”

“…Pending results of reliability tests of the total experimental procedure, and especially detailed descriptions of the sample handling before the combustion, their few results must be treated with care. Grootes et al (1989) studied the increase of the excess at 47°N (Washington) using the equal increments of a Sitka spruce for each of the years, 1962 to 1964, and even tried to ascribe each sample to the proper growth period by taking the expected varying radial growth rate into consideration. The values for 1962 are almost the same from early May to the end of September.…”

Dead wood biomass and turnover time, measured by radiocarbon, along a subalpine elevation gradient

“…We corrected outer ring 14 C values using sample-specific δ 13 C, and inner ring values using a mean δ 13 C of −22.7‰. After chemical pretreatment and correction for photosynthetic fractionation and radioactive decay, the 14 C signature of the samples should reflect that of the atmosphere at the time the growth ring was formed (Grootes et al 1989;Hua et al 1999). All outer ring 13 C and 14 C values are given in electronic supplementary Appendix S1.…”

Selection and Treatment of Data for Radiocarbon Calibration: An Update to the International Calibration (IntCal) Criteria

“…The cellulose in tree rings is formed primarily from photosynthesis in a single growing season with a component coming from carbon stored from previous years (Grootes et al 1989). Alpha-or holocellulose extraction has been used for many years but not for all tree-ring calibration samples.…”