Competition release dominates growth recovery of four subtropical broadleaved tree species following an extreme snow event

Xu, Tong-Liang

FOREST ECOLOGY AND MANAGEMENT

2026

603

Fan, ZX

The increasing frequency of extreme weather events profoundly threatens forest ecosystem functioning. Although substantial research has examined extreme snowfall impacts on subtropical forest dynamics, critical knowledge gaps persist regarding post-disturbance tree growth recovery trajectories and their mechanistic drivers. This study investigated growth recovery and resilience following a severe 2015 snowstorm in four most prevalent broad-leaved species (Stewartia pteropetiolata, Machilus yunnanensis, Schima noronhea, and Machilus gamblei) within a primary subtropical evergreen forest in the Ailao Mountain of Southwest China. By combining dendrochronological analysis with long-term census data from two 1-ha permanent plots, we quantified growth recovery patterns and their relationships with tree age/size, pre-disturbance growth performance, and competition release (sigma CI). Our results showed that snow damage impacts on radial growth, recovery, and resilience varied significantly among species. Specifically, over 50 % of Stewartia pteropetiolata and Machilus yunnanensis individuals recovered pre-snow growth rates within one year, whereas Schima noronhea and Machilus gamblei required up to four years to fully recover. Competition release (sigma CI) was the primary factor governing growth recovery and resilience. These findings provide a crucial basis for developing management strategies to sustain subtropical forest ecosystem services in the face of increasing extreme climate events.