Contact: Mari N. Jensen
University of Arizona
Caption: This cross-section of a Douglas fir from Arizona shows the tree's annual growth rings. Each ring has a light-colored band, or earlywood, that forms in the spring and a dark-colored band, or latewood, that forms in the summer. The width of the band tells how much the tree grew during that period and therefore can be used as a proxy for the climate during that season.
Credit: (c) Daniel Griffin, University of Arizona
Usage Restrictions: This image may only be used to accompany a story about the research described in the release, Monsoon Failure Key to Long Droughts in Southwest
Related news release: Monsoon failure key to long droughts in Southwest