ABSTRACT Plantations are the spearhead of adaptive silviculture, as planting stock can be selected to increase the resistance and resilience to climate‐related stressors and to accelerate the transition toward future conditions. Yet, plantations require high investments for an uncertain future outcome. Especially, we do not have a global understanding of how damage from abiotic and biotic agents relates to seedlings’ survival, and how ‘damage history’ can be modulated by silvicultural treatments. Here, we aimed at establishing the effects of timing and frequency of damage (i.e., loss of photosynthetic tissue, mechanical damage, herbivore damage, or presence of pathogens) on the survival of planted trees, using 6 years of surveys in an assisted migration experiment. Seedlings of eight species were categorized as ‘Healthy’, ‘Damaged’, or ‘Dead’ each fall. We analyzed transitions among categories using multi‐state models, a technique typical of the medical field that can be used to study disease progression. Survival and recovery of damaged seedlings declined with earlier and more frequent damage for all species, with the exception of Pinus strobus , affected by white pine blister rust. Shade‐intolerant species suffered less damage and had reduced mortality and higher recovery rates in the patch clearcut (1.2 ha), when compared to the shelterwood cut (40% of basal area removed). Shade‐tolerant species benefitted from open light conditions, either because these conditions were appropriate for a quick establishment or because of nursery's full light conditions. These results highlight the importance of providing adequate environmental conditions for quick seedling establishment, which will affect seedlings' ability to withstand damage. Although multi‐state models have limits, we propose that the study of ‘damage history’ can provide valuable insights in the context of plantations and could be expanded to other uses. Damage and recovery rates, especially, could be used as early indicators of plantation success, guiding the choices of silvicultural treatments.
Champagne et al. (Fri,) studied this question.