Climate, canker, and alder mortality in the Southern Rockies

Abstract

An increase in dieback and mortality of thinleaf alder (Alnus incana ssp. tenuifolia) raised concern in southern Wyoming and Colorado two decades ago. In 1990, there was concern over extensive mortality of thinleaf alder along Big Laramie River near Jelm, WY, as well as in multiple locations in Colorado.2 Trees of all ages were affected and Cytospora canker was associated with the mortality. In 1996, records of the Sulphur Ranger District, Arapaho National Forest indicated that a grazing allotment had severe dieback and mortality of alder (fig. 11.1). In 2005, damage was continuing, consistently associated with Cytospora canker. In other areas, property owners and biologists have noted the damage, some indicating that it began before 1995.

Parent Publication

• Forest health monitoring: 2009 national technical report

Citation

Worrall, James J. 2012. Climate, canker, and alder mortality in the Southern Rockies. In: Potter, Kevin M.; Conkling, Barbara L., eds. 2012. Forest health monitoring: 2009 national technical report. Gen. Tech. Rep. SRS-167. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 183-189.