Response of aspen stands to forest tent caterpillar defoliation and subsequent overstory mortality in northeastern Ontario, Canada

▶ Forest tent caterpillar defoliation induces mortality of trembling aspen and balsam poplar. ▶ Mortality level is also influenced by stand composition, density and tree vigor. ▶ Overstory foliage loss through defoliation promotes recruitment of understory trees and shrubs. ▶ Regenerated poplars are able to grow under heavy shrubs and residual canopies. ▶ Overstory decline accelerates transition of aspen stands to conifer dominance.