Sudden Aspen Decline Trees Dying of Thirst

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Aspen trees are a powerful icon in Colorado. A glitzy ski town is named after them, tourists come from all over to see the trees’ fall colors, and even John Denver sang about them. But around a decade ago about twenty percent of the state’s aspens were hit with something called Sudden Aspen Decline--particularly aspen trees in the southwest corner of Colorado. Stanford scientist and PhD candidate Bill Anderegg grew up in Cortez, and in 2008 he noticed the dying aspen trees during his visits back home. Anderegg wanted to know what was killing the aspens, so he spent two summers camping in Colorado’s San Juan Mountains, collecting aspen roots and branches. After running several tests, he’s come out with two major findings, which were published earlier this winter in the Proceedings of the National Academy of Sciences. Anderegg talks with Zachary Barr.

[Photo: Courtesy of Bill Anderegg]