Most studies of postfire tree recruitment have occurred in severely burned portions, despite the fact that partial burning is common. In this study we examined regeneration following a 1997 fire in the boreal forest of Quebec. A model of postfire recruitment was elaborated using parameters such as the proportion of trees killed (severity), the proportions of postfire seedbed types and their associated juvenile survivorship, the available seed supply, the available bud supply (for Populus tremuloides Michx.), and the granivory rate. All three species had peak recruitment in the first or second summer, and the recruitment episode was essentially finished after the third year. Mineral soil and surviving Sphagnum were the best seedbeds for both conifer species. Seedbed frequency was essentially independent of crown fire severity except for surviving Sphagnum, which was concentrated primarily where severity was light. Conifer fecundity was much lower in the lightly burned stands, a result we attribute to a higher granivory rate. The fecundity (seedlings/basal area for the conifers or suckers/basal area for Populus) in the severe sites was typical of the few other North American studies of postfire recruitment, where the published data permit us to make the comparison.
In North America, Eurasia, and Australia, salvage logging is increasingly being used to mitigate economic losses due to fire, although the effects of this type of intervention are still essentially unknown. In a field experiment in a large recent boreal forest fire in central Quebec, we used 24 paired salvaged and non‐salvaged stands to test the effect of salvage on the recruitment of two conifer species possessing an aerial seed bank (Pinus banksiana and Picea mariana). The seedbeds following salvage were, on average, more hospitable to germination, but, incongruously, engendered far lower regeneration densities. The poor recruitment on salvaged sites was due primarily to the loss of seeds following the immediate post‐fire salvage, when cone‐bearing branches were removed along with the trunks. By contrast, the density of the asexually‐recruited Populus tremuloides was relatively unaffected. We suggest simple ways to modify current salvage procedures that would retard this transition from conifer to Populus forest, as well as leaving more wood in situ.
A pair of elytra of the striped flea beetle Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae) was recovered from a sample of sediment dating before 1668 collected in Ville de Québec, Québec, Canada, making it the earliest recorded introduction of the species in North America. It is proposed that its transatlantic voyage took place on crucifers either voluntarily transported as foodstock and animal fodder or involuntarily as weeds.
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