Douglas-fir Cross-section Shows Annual Tree Rings (IMAGE)
Caption
Annual tree rings record a detailed history of drought (narrow rings) and wetness (wide rings). This sample from a dead Douglas-fir tree in the Santa Catalina Mountains near Tucson, Ariz., has nearly 400 rings and dates back to the year 1600. Stress cracks, visible in the foreground of the image, occur as the dead wood dries and contracts.
Credit
Copyright Daniel Griffin.
Usage Restrictions
This photo may be used only to illustrate a story about the research described in the accompanying release, Hot with Decades of Drought: Expectations for the Southwest.
License
Licensed content