Tree ring dating examples
From the 1980s, several seminal studies began at the University of Arizona (6), (7) studying the bristlecone pine of California and hohenheim oak in Germany.
Thanks to the work of these studies, we now have an 8,600 year chronology for the bristlecone pine and in the region of 12,500 year chronology for the oak.
This says nothing about either when the particular tree was felled, nor about the date it was used (8).
In past times, good quality timber may have been reused (10) and for the archaeologist, it is important to check other records against the new data.
On its own, a single record can tell us only a little about the environmental conditions of the time in a specific year of the growth of the tree, and of course the age of the tree at felling, but when we put hundreds and thousands of tree-ring records together, it can tell us a lot more.Most importantly, assuming there are no gaps in the record (and even if there are short gaps), it can tell us the precise year that a certain tree ring grew (4).The potential then, even with these two simple sets of data that we may extrapolate from the tree ring data, is enormous.American Astronomre A E Douglass, who had a strong interest in studying the climate, developed the method around 1900 (4).He theorised that tree rings could be used as proxy data to extend climate study back further than had previously been permissible.