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Tree rings : timekeepers of the past

January 1, 1973

A casual look at the top of a tree stump reveals that it is composed of a series of concentric rings-tree rings -that become larger and larger in diameter outward from the center of the stump. Because a single tree ring is usually formed each year, the age of the tree at the time it was cut can be determined by simply counting the rings. If the year of cutting is known, the year during which each ring was formed can be determined by counting backwards from the outside ring. Such "dating" of rings may reveal that rings formed during certain extreme drought years are unusually narrow. This has led to speculation that tree ring characteristics may indicate a number of things about past water and climatic conditions.

Citation Information

Publication Year 1973
Title Tree rings : timekeepers of the past
DOI 10.3133/7000082
Publication Type Report
Publication Subtype USGS Unnumbered Series
Series Title General Interest Publication
Index ID 7000082
Record Source USGS Publications Warehouse