Leclerc M.,University of Quebec at Rimouski |
Dussault C.,Ministere des Forets |
St-Laurent M.-H.,University of Quebec at Rimouski
Oecologia | Year: 2014
Behavioural strategies may have important fitness, ecological and evolutionary consequences. In woodland caribou, human disturbances are associated with higher predation risk. Between 2004 and 2011, we investigated if habitat selection strategies of female caribou towards disturbances influenced their calf's survival in managed boreal forest with varying intensities of human disturbances. Calf survival was 53 % and 43 % after 30 and 90 days following birth, respectively, and 52 % of calves that died were killed by black bear. The probability that a female lose its calf to predation was not influenced by habitat composition of her annual home range, but decreased with an increase in proportion of open lichen woodland within her calving home range. At the local scale, females that did not lose their calf displayed stronger avoidance of high road density areas than females that lost their calf to predation. Further, females that lost their calf to predation and that had a low proportion of ≤5-year-old cutovers within their calving home range were mostly observed in areas where these young cutovers were locally absent. Also, females that lost their calf to predation and that had a high proportion of ≤5-year-old cutovers within their calving home range were mostly observed in areas with a high local density of ≤5-year-old cutovers. Our study demonstrates that we have to account for human-induced disturbances at both local and regional scales in order to further enhance effective caribou management plans. We demonstrate that disturbances not only impact spatial distribution of individuals, but also their reproductive success. © 2014 Springer-Verlag Berlin Heidelberg.
Beaulieu J.,Natural Resources Canada |
Beaulieu J.,Laval University |
Doerksen T.K.,Natural Resources Canada |
Doerksen T.K.,Laval University |
And 3 more authors.
BMC Genomics | Year: 2014
Background: Genomic selection (GS) may improve selection response over conventional pedigree-based selection if markers capture more detailed information than pedigrees in recently domesticated tree species and/or make it more cost effective. Genomic prediction accuracies using 1748 trees and 6932 SNPs representative of as many distinct gene loci were determined for growth and wood traits in white spruce, within and between environments and breeding groups (BG), each with an effective size of N e ≈ 20. Marker subsets were also tested. Results: Model fits and/or cross-validation (CV) prediction accuracies for ridge regression (RR) and the least absolute shrinkage and selection operator models approached those of pedigree-based models. With strong relatedness between CV sets, prediction accuracies for RR within environment and BG were high for wood (r = 0.71-0.79) and moderately high for growth (r = 0.52-0.69) traits, in line with trends in heritabilities. For both classes of traits, these accuracies achieved between 83% and 92% of those obtained with phenotypes and pedigree information. Prediction into untested environments remained moderately high for wood (r ≥ 0.61) but dropped significantly for growth (r ≥ 0.24) traits, emphasizing the need to phenotype in all test environments and model genotype-by-environment interactions for growth traits. Removing relatedness between CV sets sharply decreased prediction accuracies for all traits and subpopulations, falling near zero between BGs with no known shared ancestry. For marker subsets, similar patterns were observed but with lower prediction accuracies. Conclusions: Given the need for high relatedness between CV sets to obtain good prediction accuracies, we recommend to build GS models for prediction within the same breeding population only. Breeding groups could be merged to build genomic prediction models as long as the total effective population size does not exceed 50 individuals in order to obtain high prediction accuracy such as that obtained in the present study. A number of markers limited to a few hundred would not negatively impact prediction accuracies, but these could decrease more rapidly over generations. The most promising short-term approach for genomic selection would likely be the selection of superior individuals within large full-sib families vegetatively propagated to implement multiclonal forestry. © 2014 Beaulieu et al.
Gauthier S.,Natural Resources Canada |
Raulier F.,Laval University |
Ouzennou H.,Ministere des Forets |
Saucier J.-P.,Ministere des Forets
Canadian Journal of Forest Research | Year: 2015
As fire is a major disturbance in boreal forests, it is now recognized that it has to be taken into account in forest management planning. Moreover, as the time of exposure to fire is related to stand productivity, combining information on productivity and fire should help in assessing the potential to sustainably manage forests. We present a method to assess potential vulnerability to the risk of fire and illustrate it in the boreal coniferous forest of Quebec. This method takes into account some sources of uncertainty related to the estimation of productivity and fire risk. Spatialization of stand productivity from growth and yield curves allowed us to compute the area comprised of productive stands of each district with or without considering fire risk. Results showed that productive area is generally decreasing with decreasing degree-days, increasing elevation, or in relation to surficial geology. Furthermore, districts with moderate to good productivity were found to be vulnerable to fire when burn rates were greater than 0.333%·year–1. Our innovative approach allowed us to assess the vulnerability of the districts to fire and could be helpful in many regions in the context of a projected increase in future area burned under climate change. © 2015, Canadian Journal of Forest Research. All right reserved.
Robitaille A.,Ministere des Forets |
Saucier J.-P.,Ministere des Forets |
Chabot M.,Ministere des Forets |
COtE D.,Ministere des Forets |
Boudreault C.,University of Quebec at Montreal
Canadian Journal of Forest Research | Year: 2015
Constraints of the physical environment affect forest growth and forest operations. At a local scale, these constraints are generally considered during forest operations. At regional or continental scales, they are often integrated to larger assessments of the potential for a given land unit to be managed. In this study, we propose an approach to analyze the integration of physicalenvironment constraints in forest management activities at the regional scale (482 000 km2). The land features that pose constraints to forest management (i.e., hydromorphic organic deposits, dead-ice moraines, washed till, glacial block fields, talus, and active aeolian deposits, slopes > 40%) were evaluated within 1114 land districts. To distinguish land districts that can be suitably managed from those where constraints are too important for sustainable timber production, we carried out a sensitivity analysis of physical constraints for the 1114 land districts. After analysis of two portions of the study area under management, a land district was considered suitable for management when more than 20% of its land area consists of features imposing few constraints or, for mountain-type relief districts, when more than 40% of the land area consists of features imposing few constraints. These cutoff values were defined by expert opinion, based on sensitivity analyses performed on the entire study area, on analyses of two different sectors with different types of constraints and on a strong understanding of the study area. Our results show that land districts where the physical environment posed significant constraints covered 7.5% of the study area (36 000 km2). This study shows that doing an a priori classification of land units based on permanent environmental features could facilitate the identification of areas that are not suitable for forest management activities. © 2015, National Research Council of Canada. All right reserved.
Imbeau L.,University of Quebec |
St-Laurent M.-H.,University of Quebec at Rimouski |
Marzell L.,Ministere des Ressources Naturelles et de la Faune |
Brodeur V.,Ministere des Forets
Canadian Journal of Forest Research | Year: 2015
Long-term exploitation of boreal ecosystems often results in a reduced range of ecological conditions that threatens several species. In most boreal jurisdictions, the northern extent of commercial forestry corresponds to economical rather than ecological considerations. Our general objective is to offer guidance for sustainable boreal forest management by using a biodiversity criterion based on three indicators. The first two indicators are part of a coarse filter referring to the proportion and fragmentation of tall, dense forest habitats, whereas a third one uses a fine filter for specific requirements of boreal caribou. We applied the methodology with and without anthropogenic disturbances on 1114 land districts to contrast the preindustrial potential and current capacity of Quebec's boreal forest to support forest management. Originally, 826 districts (74%) were above the 20% cutoff value for the minimum proportion of tall, dense forest habitats. Among the 567 districts currently under forest management, 45 did not reach this value because of past anthropogenic disturbances. Originally, 88% of the districts had sufficient undisturbed habitats to maintain caribou populations, but anthropogenic disturbances reduced this proportion to 51%. The proposed methodology could contribute to delineating areas where sustainable forest management can be implemented. Our results also clearly show that management targets of the last decades were insufficient to prevent loss of habitats below strict minimum ecological thresholds. Our approach offers a general framework that could be adapted to other forested regions to attain similar biodiversity conservation objectives. © 2015, National Research Council of Canada. All right reserved.