A methodology for estimating canopy disturbance frequency and intensity in dense temperate forests

A methodology is proposed for developing a disturbance chronology in stands by identifying the probable date of canopy accession for each sample tree. Canopy disturbance intensity is defined as the percentage of sample trees with canopy accession events in each decade. Rotation periods for disturbances of various intensities are calculated from the chronology. The method was evaluated using 893 increment cores from 70 plots in northern hardwood stands of W Upper Michigan. Average disturbance rate for all plots and decades was 5.7-6.9% of land area per decade, with an implied average canopy tree residence time of 145-175 yr. -from Authors