Beetle-Killed Engelmann Spruce its Deterioration in Colorado

An estimated 4.3 billion board feet of Engelmann spruce and lodge-pole pine sawtimber was killed by the Engelmann spruce beetle during a major Colorado epidemic from 1941 to 1952. A study on the rate of deterioration in these stands was begun in 1951. Results indicate that about 40 percent of the original cubic-foot volume has been lost 20 years after kill. About one-third of this loss is due to decay in standing trees, two-thirds to windthrow. It is anticipated that windthrow will be a progressively more important deterioration factor in the future.