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New results of carbon isotopic composition from tree rings have been analyzed. Δ14C and δ13C data, representing the isotopic composition of carbon in “clean air”, were obtained from annual rings of a pine tree (Pinus sylvestris) taken in the Niepolomice area, 25 km east Krakow, Poland. All samples were processed to extract α-cellulose, and the radiocarbon concentration in each annual ring was measured using AMS at the University of Nagoya. Stable isotopic composition of carbon was determined using isotope ratio mass spectrometry. The dataset covers the growth period between 1960 and 2003. The average difference between radiocarbon concentrations in Niepolomice and the North Hemisphere zone 1 (NH zone 1) for the period between 1960 and 1999 is 3.5 ± 1.6‰. These data are compared with previously presented results from the city of Krakow, where a local decrease in 14C concentration was observed due to local CO2 emission from fossil fuel use. The differences in observed 14C concentrations were used to estimate a magnitude of the local Suess effect in Krakow. Based on mass balance equations for CO2 14C concentrations, it was possible to calculate the CO2 concentration associated with fossil fuel emission (Cfoss) into the atmosphere. The highest values of Cfoss were recorded in the years 1986 (11.9 ± 1.4 ppm V) and 1983 (8.1 ± 1.3 ppm V), while the lowest value of 0.6 ± 1.8 ppm V was recorded in 2001.

Recently radiocarbon (14C) concentration in the atmospheric CO2 has decreased over time due to the exchange of CO2 between atmosphere and ocean, but also due to emission of 14C free-CO2 from burning fossil fuels. The second contribution, known as the Suess effect, can be observed in the highly industrialized and/or urban area. 14C concentrations in annual rings of a pine tree from the urban area in Nagoya, Japan, that grew over the last 24 years were measured with AMS to be remarkably lower than those observed in “clear air” of corresponding years at Schauinsland station in Germany. The measured data were used to estimate the rate of the fossil component in atmospheric CO2 that was derived from fossil fuel burning. Exponential and linear functions were fitted to the secular variations of 14C concentration in annual rings to calculate the decay constant and an average decreasing rate of 14C concentration. The result suggests that the use of annual rings of trees to obtain the secular variations of 14C concentration of atmospheric CO2 can be useful and efficient for environmental monitoring and modeling of the carbon distribution in local scale.

New results of radiocarbon concentration in tree rings from the City of Valladolid (Spain) covering a growth period of 22 year have been measured using an AMS. Samples were taken using a hollow drill from a living tree, and α-cellulose was extracted from each of annual rings (early and late wood separately). The set of data shows lower radiocarbon concentration than that reported for “clean air” at the reference station, indicating a remarkable input of “dead” CO 2 of fossil fuel origin. Using data of carbon dioxide and 14 C concentrations from Schauinsland, the corresponding summer and winter values of the fossil component ( c f ) in carbon dioxide were calculated for the City of Valladolid. By fitting exponential and linear functions to the experimental data, the exchange time was calculated, and the expected future 14 C concentration in the atmosphere was estimated.

Radiocarbon and 210Pb were measured on the uppermost 40 cm of a Wardenaar peat core retrieved from a Baltic raised bog at Słowińskie Błota (Pomerania, North Poland). This site is the subject of ongoing multiproxy studies covering the last 1300 years. Radiocarbon age model was constructed on the basis of 14 AMS dates obtained on selected Sphagnum spp. fragments, with use of P_Sequence tool. We present here a comparison of this model with the age model obtained using CRS model classically applied to 210Pb measurements.