Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed in order to analyze atmospheric conditions during different periods in history.
Dendrochronology is useful for determining the timing of events and rates of change in the environment (most prominently climate) and also in works of art and architecture, such as old panel paintings on wood, buildings, etc.
Since cross-dating depends on matching the high-frequency elements of a sample against a master chronology, various methods are explored for removing the low-frequency variance in ring-width series before they are compared.
The results show that a range of such “pre-whitening” methods can usefully be employed, and no single method is universally superior.
A tree's growth rate changes in a predictable pattern throughout the year in response to seasonal climate changes, resulting in visible growth rings.
Then, ecologically relevant comparisons with environmental can be investigated.
Example: analyzing ring widths of trees to determine how much rainfall fell per year long before weather records were kept.
The science that uses tree rings to study factors that affect the earth's ecosystems.
In 1859, the German-American Jacob Kuechler (1823–1893) used crossdating to examine oaks (Quercus stellata) in order to study the record of climate in western Texas.
During the first half of the 20th century, the astronomer A. Douglass founded the Laboratory of Tree-Ring Research at the University of Arizona.