(den-droh-cruh-NOL-uh-gee) means “the study of tree time.” Usually called tree-ring dating, dendrochronology is a science based on the fact that every growth season a tree adds a new layer of wood to its trunk.
Over time, these yearly growth layers form a series of light and dark concentric circles, or tree rings, that are visible on cross sections of felled trees.
By counting the dark ring segments, scientists can tell a tree’s age if the cross section of the trunk is complete. Based at the University of Arizona in Tucson, Douglass wanted to know how sun spot activity affected climate, and his research soon led him to pioneering tree-ring analysis.
Because the width of tree rings varies with growing conditions, scientists also learn about local climate during the tree’s lifetime by comparing the rings’ different widths. For instance, higher rainfall and a longer growing season produces a wider ring than a year with low rainfall and prolonged cold. Douglass was among the first to notice that trees in a geographic area develop the same growth-ring patterns because they experience the same climatic conditions.
This results in the cambium cells becoming smaller and thicker-walled.
By winter, when the sap finally stops flowing, a smooth dark ring marks the end of the tree’s annual growth.
We are centrally located near Maggie Valley and historic Haywood County, North Carolina just minutes from the Blue Ridge parkway and Cataloochee Valley in the Great Smoky Mountains National Park.