They can determine the exact calendar year each tree ring was formed.Dendrochronological findings played an important role in the early days of radiocarbon dating.
It is also worth noting that the half-life used in carbon dating calculations is 5568 years, the value worked out by chemist Willard Libby, and not the more accurate value of 5730 years, which is known as the Cambridge half-life.
Although it is less accurate, the Libby half-life was retained to avoid inconsistencies or errors when comparing carbon-14 test results that were produced before and after the Cambridge half-life was derived.
The first calibration curve for radiocarbon dating was based on a continuous tree-ring sequence stretching back to 8,000 years.
This tree-ring sequence, established by Wesley Ferguson in the 1960s, aided Hans Suess to publish the first useful calibration curve.
Suess’s curve, based on the bristlecone pine, used tree rings for its calendar axis.