Dendrochronology vs carbon dating
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.
Alder and pine are notorious for occasionally “missing a year” which is confusing enough without the fact that those species also sometimes “double up”, by having two rings in the same growth season (8).
It was not until the 1970s that archaeologists saw the benefits of the use of tree ring data in their own field (8), even though Douglass himself had used his method to date many prehistoric North American artefacts and monuments that had previously not been satisfactorily placed into a definite chronology.
We can see this in any tree stump, a series of concentric rings circling the heart wood and fanning out towards the edge.
Naturally, the outer rings represent the youngest years of the tree and you may notice that not all rings are uniform - some are thinner, some thicker, some light and some dark.
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.