Odds of a fire reaching one of 3 size classes.

Estimates odds ratio (solid lines) and 95% confidence bounds (dashed lines) of fire reaching one of 3 size classes as the values of two predictors (bark beetle and spruce budworm) increase. The odds ratio is relative to when there is no insect infestation. The red dashed line indicates an odds ratio of one. When the red line is within the 95% bounds the odds is not significantly different from the odds when no insect infestation is present.