A study on the correlation between 13C/12C variations in tree rings and the growth pattern of trees

A specimen of Araucaria angustifolia from the south of Brazil was analyzed for ¹³C/¹²C variations in the cellulose of the tree rings. Those data, when compared with the growth pattern of the tree, showed a good correlation (r = ? 0.72) over a period of 200 years. A collection of six European trees was analyzed for the same effect and, although the expected inverse relation is evident from the graphical representation, the correlation coefficients are small. This is certainly due to the large scatter of δ¹³C data from those trees.