COMPARING BOREAL FOREST REGENERATION STRUCTURES BETWEEN HARVESTING AND WILDFIRE DISTURBANCE WITH 3D MORPHOLOGY

Abstract

Quantifying landscape structure is central to understanding boreal forest disturbance and recovery. This study examined the three-dimensional morphological structure of post-disturbance regeneration following 30 events in Ontario (15 wildfires and 15 harvests). Annual binary land-cover maps were stacked into temporal voxel cubes (x, y, t) and segmented into eight 3D morphological classes. Site-level morphological proportions were analyzed using univariate and multivariate statistical methods to evaluate differences among disturbance types and ecoregions. Wildfire sites contained significantly higher proportions of MASS, while harvested sites contained significantly higher proportions of BOND (p < 0.05). Morphological composition also differed significantly between ecoregions, with western sites exhibiting greater MASS, VOID-VOLUME, and VOID proportions and eastern sites showing greater CRUMB and CIRCUIT proportions (p < 0.05). Wildfire sites displayed greater structural consistency, whereas harvested sites showed higher variability. These findings indicate that harvesting does not replicate wildfire regeneration patterns and that disturbance type and regional context jointly influence boreal forest recovery.