Prediction of mortality in Appalachian sugar maple stands affected by dieback in southeastern Quebec, Canada

The objectives of this study were to predict the survival probability of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britton) affected by dieback and to evaluate the critical threshold beyond which mortality caused by dieback is inevitable. Mortality and dieback growth rate of all the trees in 133 sample plots located in the Appalachian region of southeastern Quebec were measured annually from 1984 to 1993. These measurements were associated with the evaluation of the intensity of dieback. Results indicated that the mortality of sugar maple and yellow birch was related to the progression of dieback. Inversely, in the majority of cases, mortality occurred only when dieback increased in intensity and affected trees with different rates of missing foliage.