Radiocarbon Concentration in Annual Tree Rings from the Salamanca Region, Western Spain

Tree-ring samples were taken from a from a pine tree (Pinus pinea) growing in Villar de Peralonso, a rural area 50 km west of the city of Salamanca, Spain. All samples were processed to extract α-cellulose and the radiocarbon concentration in each annual ring was measured using accelerator mass spectrometry (AMS) at the University of Nagoya, Japan. The data set covers a growth period between 1979 and 2006, and represents the concentrations of 14C in a “clean area.” The average difference between 14C concentrations in Villar de Peralonso and NH zone 1 for the period 1979–1999 is 4.1 ± 1.3%. A sample was taken to obtain the reference level of 14C for the Iberian Peninsula, for a study of anthropogenic emission of CO2 in urban areas. As part of the initial study, 14C concentration data in tree rings from the city of Valladolid were used to recalculate the fossil fuel component (cfoss) using reference data from Villar de Peralonso.