On the13C record in tree rings. Part I.13C Variations in northern hemispheric trees during the last 150 years

Open Access
Publisher Website
Google Scholar
Abstract
13C data from 26 trees of different northern hemispheric locations are presented covering the time interval of the last 150 years. It has been found that the mean 13C data of these trees during the 1850–1920, 1920–1940 and 1960–1975 time intervals decrease with an almost linear slope, while the data in the 1940–1960 time interval are increasing. The total ?13C shift since industrialization found from our trees amounts to nearly ?29% which is higher than the linear ?13C decrease of ?1%/100 years due to the biogenic and fossil CO2 input into the atmosphere, as assumed previously in model calculations of Siegenthaler et al. (1978). The mean data within the given error-probability correspond to those of other authors with the exception of the data for the 1920–1940 time interval. The disturbances in 13C data for recording of increasing atmospheric CO2 levels have been pointed out. DOI: 10.1111/j.2153-3490.1979.tb00889.x