High-precision radiocarbon dating of a millennium-old yellowwood tree from
the Midlands of Natal shows that the tree-rings do, in general, record annu
al growth, but that both missing and false rings occur. At two places along
the transect of the trunk there are blocks of 19 and 143 missing rings, re
spectively, and during the time of most rapid growth some 20 false rings ar
e identified. By matching the C-14 results to the radiocarbon calibration c
urve, an uncertainty of only two or three years is achieved in the dating.
The data illustrate that the age of a tree can be determined accurately wit
h radiocarbon, but this does require the analysis of several samples. The r
ing-width analysis shows periods of slower and more rapid growth over the c
enturies that are interpreted as reflecting changes in the precipitation ra
te in the summer rainfall region of South Africa. Five exceptionally narrow
rings around 1820 suggest that five years of severe drought after two deca
des of very high rainfall may have been a contributing factor to the widesp
read tribal warfare and devastation that occurred at that time.