Damage to lodgepole pine (Pinus contorta) through the removal of bark by small animals is having a severe impact on the survival and productivity of stands near Hinton, Alberta. 58% of the Forest Management Agreement Area is Lodgepole pine. This study was set up to address the following objectives (1) to determine what animal species is responsible for the damage of concern, (2) to determine when the damage occurs, (3) to determine the patterns of damage and characteristics of trees attacked, and (4) to determine what characteristics make a stand vulnerable to attack.

Sixty-seven plots, located in four compartments were sampled from the end of May through August 1991. Damage began in early June and continued through mid July of 1991. Eighteen percent of the trees surveyed were subject to new damage, 68% of previously damaged trees were re-damaged, while only 32% of undamaged trees were damaged. Trees with previous damage were more likely to be re-attacked than undamaged trees. In order to correctly identify the damaging animal, the timing, location, appearance and diameter of trees attacked were examined. The causal agent of the damage was red squirrels, not snowshoe hares as previously believed.

The last objective of this study was addressed through analysis of a large data set provided by Weldwood of Canada (Hinton Division). This data set was composed of information collected from 1988 to 1989 over the entire Forest Management Agreement Area. No differences were found between the characteristics of damaged and undamaged stands on either a plot or block basis. This may be due to incomplete measurement of damage or information not included in the data set.