『Abstract
　In this study, we test whether the δ¹³C and δ¹⁵N in a peat profile are, respectively, linked to the recent dilution of atmospheric δ¹³CO2 caused by increased fossil fuel combustion and changes in atmospheric δ¹⁵N deposition. We analysed bulk peat and Sphagnum fuscum branch C and N concentrations and bulk peat, S. fuscum branch and Andromeda polifolia leaf δ¹³C and δ¹⁵N from a 30-cm hummock-like peat profile from an Aapa mire in northern Finland. Statistically significant correlations were found between the dilution of atmospheric δ¹³CO2 and bulk peat δ¹³C, as well as between historically increasing wet N deposition and bulk peat δ¹⁵N. However, these correlations may be affected by early stage kinetic fractionation during decomposition and possibly other processes. We conclude that bulk peat stable carbon and nitrogen isotope ratios may reflect the dilution of atmospheric δ¹³CO2 and the changes in δ¹⁵N deposition, but probably also reflect the effects of early stage kinetic fractionation during diagenesis. This needs to be taken into account when interpreting palaeodata. There is a need for further studies of δ¹⁵N profiles in sufficiently old dated cores from sites with different rates of decomposition: These would facilitate more reliable separation of depositional δ¹⁵N from patterns caused by other processes.

Keywords: Carbon dioxide; Nitrogen deposition; Stable isotopes; Peat; Sphagnum fuscum; Diagenesis』

1. Introduction
2. Material and methods
　2.1. Site and sampling
　2.2. Laboratory methods
　2.3. Isotope expression
　2.4. Age
　2.5. Atmospheric CO2 and δ¹³C
　2.6. Atmospheric N deposition and δ¹⁵N
　2.7. Statistical analysis
3. Results
4. Discussion
　4.1. Bulk peat and S. fuscum C and N
　4.2. Relationship between the dilution of δ¹³C in atmospheric CO2 and bulk pea, S. fuscum C and A. polifolia
　4.3. Relationship between atmospheric N deposition and bulk pea, S. fuscum and A. polifolia δ¹⁵N
5. Conclusions and future work
Acknowledgements
Open access
References