Tadeusz Splawinski, Yan Boucher, David M. Green, Sylvie Gauthier, Mathieu Bouchard, Isabelle Auger, Luc Sirois, Yves Bergeron, Osvaldo Valeria. Factors influencing black spruce reproductive potential in the northern boreal forest of Quebec. 2022. Can. J. For. Res. 52(12):1499-1512
DOI : 10.1139/cjfr-2022-0092
The reproductive ecology of the semi-serotinous species black spruce (Picea mariana (Mill.) BSP) in northern boreal forests remains poorly understood. There is a general lack of data on cone/seed production and viability as a function of biotic tree-level characteristics and abiotic variables. No studies currently exist to quantify these differences over a large gradient in temperature, elevation, and precipitation. Extensive physical, ecological, dendrometric, and reproductive data were collected from young to very old black spruce stands in northern Quebec. ANOVA and general linear mixed models were used to examine interannual cone production, and the relative importance of the biotic and abiotic explanatory factors in determining total cone production; length of the cone-bearing zone; filled seeds per cone; proportion of filled seeds; and seed viability. The results illustrate that the reproductive ecology of black spruce in northern cold forests is mainly explained by biotic variables such as age and diameter at breast height, and by abiotic variables related to temperature such as elevation, length of the growing season, and growing degree-days. Black spruce exhibits a lower reproductive potential in northern cold forests, making it possibly less resilient to increased fire frequency, particularly in unproductive and very young or very old stands.
Maryse Marchand, Jeanne Moisan Perrier, Louis-Étienne Robert, Loïc D'Orangeville, Mathieu Bouchard, Daniel Kneeshaw, Louis De Grandpré. Forest Structure and Composition Diverge Following Harvesting Compared to a Spruce Budworm Choristoneura fumiferana (Clem.) Outbreak 2022. Frontiers in forests and global change 5
DOI : 10.3389/ffgc.2022.680262
Balsam fir (Abies balsamea) is the most vulnerable species to the spruce budworm (Choristoneura fumiferana), one of the most devastating defoliators in the world. For decades, pest managers have advocated for reducing its abundance in the landscape to minimize losses to the spruce budworm (SBW). Although reduction of fir occurred during the endemic phase of the SBW cycle, there is little information about the extent to which this general principle (reduction of fir) was applied during an outbreak and whether it occurs at both stand and landscape levels. The objective of this paper is to compare the effect of insect and harvest disturbances on forest structure during the 1970–80s outbreak in Québec. We evaluate whether, (i) forest management activities targeted fir forests and whether patch size of host species influences management or SBW disturbance, (ii) SBW outbreaks and logging have similar or divergent effects on forest composition. Although data are from an earlier outbreak, they are at a scale rarely studied and will be useful in guiding decisions made at larger scales in the current and future outbreaks. Our results show that spruce was targeted preferentially by harvesting (up to 69% of plots) during the outbreak period, while it represented less than one third of plots defoliated by the SBW. On the other hand, fir stands represented up to 75% of plots that were defoliated by the SBW but less than 35% of plots that underwent harvesting. Harvesting targeted large blocks of spruce forest more than large blocks of fir-dominated forest while the opposite was observed for the SBW. In terms of regeneration, SBW tends to reduce fir and favor spruce recruitment, along with non-host species, whereas the opposite tendency was observed following harvesting. In terms of spatial organization of stands, our results support the suggestion that small stands of fir and large stands of spruce undergo the least SBW damage. Thus, in order to attenuate SBW impacts in the future, efforts should be made to ensure that spruce recruitment is favored and that its abundance increases at both the stand and landscape scale.
Mathieu Bouchard, Nicole J. Fenton, Marion Barbé. Examining boreal forest resilience to temperature variability using bryophytes: forest type matters. 2020. Ecosphere 11(8):e03232
DOI : 10.1002/ecs2.3232
The capacity of individual species to tolerate environmental changes is a major driver of ecosystem resilience. This subject has been a hot topic in boreal forests due to the greater effect of climate change anticipated at northern latitudes. However, to date it has been mainly examined for trees, with comparatively little emphasis on other species groups. In this study, bryophytes were sampled in the boreal forest of Québec (Canada) using a stratified sampling design allowing us to separate the effect of dominant canopy composition (two types: coniferous and mixedwood) and of the spatial climatic gradient (relatively warm and relatively cold sites) on bryophyte community structure (species richness and composition). The results indicated that bryophyte composition was different between coniferous and mixedwood stands. The impacts of spatial variation in climate were more visible in mixedwood than coniferous stands, indicating an interaction between stand type and climate. Specifically, bryophytes from mixedwood stands, and particularly specialist communities associated with deadwood and live tree bases, were climate?sensitive and represent a potential target group to investigate the effects of climate change. In contrast, bryophyte communities from coniferous stands are stand structure?sensitive, with little response to climate, presumably partly because coniferous canopies buffer climatic variations. Since bryophyte community sensitivity to regional variations in climatic conditions depends on dominant canopy characteristics and microhabitat availability, we suggest that adapted forest management practices could play a role in attenuating climate change impacts on these organisms.
Louis De Grandpré, Kaysandra Waldron, Mathieu Bouchard, Marilou Beaudet, Jean-Claude Ruel, Christian Hébert, Sylvie Gauthier, Daniel Kneeshaw. Incorporating Insect and Wind Disturbances in a Natural Disturbance-Based Management Framework for the Boreal Forest. 2018. Forests 9(8):471
DOI : 10.3390/f9080471
Natural disturbances are fundamental to forest ecosystem dynamics and have been used for two decades to improve forest management, notably in the boreal forest. Initially based on fire regimes, there is now a need to extend the concept to include other types of disturbances as they can greatly contribute to forest dynamics in some regions of the boreal zone. Here we review the main descriptors—that is, the severity, specificity, spatial and temporal descriptors and legacies, of windthrow and spruce bud worm outbreak disturbance regimes in boreal forests—in order to facilitate incorporating them into a natural disturbance-based forest management framework. We also describe the biological legacies that are generated by these disturbances. Temporal and spatial descriptors characterising both disturbance types are generally variable in time and space. This makes them difficult to reproduce in an ecosystem management framework. However, severity and specificity descriptors may provide a template upon which policies for maintaining post harvesting and salvage logging biological legacies can be based. In a context in which management mainly targets mature and old-growth stages, integrating insect and wind disturbances in a management framework is an important goal, as these disturbances contribute to creating heterogeneity in mature and old-growth forest characteristics.
Deepa Pureswaran, Mathieu Bouchard, Louis De Grandpré, Daniel Kneeshaw. Climate-induced range shifts in boreal forest pests: ecological, economic, and social consequences. 2018. Can. J. For. Res. 48(3):v-vi
DOI : 10.1139/cjfr-2018-0058
Climate change is causing northward shifts in species ranges. For mobile species such as insects, this will increase their access to forest ecosystems where in the past their presence and impact was limited. Range expansion and increases in outbreak severity of forest pests have been documented in Europe and North America (Jepsen et al. 2008; Bentz et al. 2010). Temperature-mediated phenological changes and trophic interactions among host trees, herbivorous insects, and their natural enemies are linked to the long-term effects of range expansion on boreal ecosystems. The degree to which temperate and boreal forest ecosystems are resilient to novel disturbance regimes will have direct consequences on the provisioning of goods and services from these forests and on long-term forest management planning. These concerns were the impetus for the organization of a workshop on climate-induced range shifts in boreal forest pests. Contributions to this special feature are selected papers from the International Union of Forest Research Organizations (IUFRO) workshop held in July 2016 in northeastern Quebec. The workshop was organized around five themes related to the consequences of range shifts of boreal forest insect pests: (1) plant–insect phenology, (2) species range expansions, (3) ecosystem response to changes in disturbance regimes, (4) interactions among disturbances, and (5) forest management and adaptation to change.
Louis Bélanger, Yves Bergeron, Catherine Périé, Mathieu Bouchard, Pierre Bernier, Christian Messier. L’aménagement écosystémique
des forêts dans le contexte des changements climatiques – Rapport du comité d’experts, Québec. 2017. COMITÉ D’EXPERTS SUR L’AMÉNAGEMENT ÉCOSYSTÉMIQUE DES FORÊTS ET LES CHANGEMENTS CLIMATIQUES. 29 p.
Yves Bergeron, Pierre Drapeau, Mathieu Bouchard, Martin-Hugues St-Laurent, Catherine Boudreault, Louis Imbeau. Contrasting responses of epiphytic and terricolous lichens to variations in forest characteristics in northern boreal ecosystems. 2015. Can. J. For. Res. 45(5): 595-606
DOI : 10.1139/cjfr-2013-0529
Les principaux facteurs qui déterminent la composition des communautés de lichens sont encore mal connus dans les écosystèmes boréaux nordiques. Cette étude compare les effets des caractéristiques (hauteur, couvert forestier et âge) des peuplements forestiers sur les communautés de lichens épiphytes fruticuleux et terricoles à travers une vaste région située à la limite ente les forêts boréales à couvert fermé et les forêts nordiques ouvertes dans la province de Québec (Canada). Le jeu de données est composé de 875 placettes réparties sur un territoire de 242?000 km2 qui s’étend entre les extrémités est et ouest de la province. La biomasse des lichens épiphytes fruticuleux (Alectoria, Bryoria, Evernia et Usnea) a été évaluée à l’échelle de la branche, de l’arbre et de la placette; le recouvrement de lichens terricoles (Cladonia spp.) a été évalué à l’échelle de la placette. Les résultats montrent que les lichens épiphytes et terricoles réagissent de façon significative mais différente aux variations des caractéristiques de la forêt. À l’échelle de la placette, la biomasse des lichens épiphytes était la plus élevée dans les plus vieux peuplements (>100 ans), et la plus faible dans les peuplements avec un faible couvert forestier (<25%) ou dans les peuplements dominés par des arbres de petite taille (<7 m). Par contre, le recouvrement de lichens terricoles était le plus élevé dans les peuplements dominés par des arbres de petite taille (<7 m) ou de taille intermédiaire (7–12 m) et le plus faible dans les peuplements avec un couvert forestier relativement important (>40 %) ou dans les peuplements d’âge intermédiaire (60–100 ans). La composition en espèces des communautés épiphytes a également été étudiée et certaines espèces ou genres étaient étroitement associés aux peuplements plus vieux (Alectoria sarmentosa (Ach.) Ach., Bryoria spp.), ou à des régions particulières le long du gradient est-ouest d’environ 1500 km (Evernia mesomorpha Nyl. à l’ouest, Bryoria spp. au centre et A. sarmentosa à l’est). En termes de conservation, ces résultats indiquent que les communautés de lichens épiphytes sont potentiellement sensibles à l’exploitation préférentielle des vieux peuplements. Les communautés de lichens épiphytes et terricoles sont aussi potentiellement sensibles aux effets appréhendés des changements climatiques tels que l’augmentation de la fréquence des feux ou l’augmentation de la croissance de la forêt.
Yves Bergeron, Darwin Coxson, Susan Stevenson, Catherine Boudreault, Mathieu Bouchard. Do forests treated by partial cutting provide growth conditions similar to old-growth forests for epiphytic lichens? 2013. Biological Conservation 159(1): 458-467
DOI : 10.1016/j.biocon.2012.12.019.
In boreal forests, partial cutting is increasingly proposed as a suitable alternative to the widespread use of clearcutting in order to conciliate forest management with habitat conservation for epiphytic species. We compared the growth of two epiphytic lichen species, Bryoria nadvornikiana and Evernia mesomorpha, in old forest stands recently treated by partial cutting and untreated controls, located in black spruce boreal forests of western Québec. Lichen growth rates were measured over a period of two years from transplants of the two species, and several environmental variables (e.g., canopy openness, thallus temperature, and thallus wetness) were also measured directly at the sampling sites. Despite important within-treatment variation in growth rates among transplants, we observed reduced growth rates in partial cuts for both species. Canopy openness measurements of more than 40% resulted in negative growth rates for B. nadvornikiana, a species typically associated with relatively closed canopies, and canopy openness over 70% resulted in negative growth rates for E. mesomorpha, a species that tends to be associated with open canopies. This negative growth response contrasts with what is generally reported in the literature about the effect of canopy opening creation on epiphytic lichen growth. As a function of the environmental parameters that were measured on site, we suggest that a reduction in the duration of hydration periods, and an increased risk of thallus fragmentation in partially cut stands, especially for B. nadvornikiana, could explain this result. Because this negative effect could be more likely to occur during dry periods, future trends in the response of epiphytic lichens to the creation of canopy openings could be influenced by climate change. This study suggest that even if partial cuts can be a good alternative to clearcutting for the conservation of epiphytic lichen species, they are more likely to succeed if dense clumps of residual trees (canopy cover > 70%) are retained in the treated stands.
Mathieu Bouchard, Yves Bergeron, Daniel Kneeshaw. Ecosystem management based on large-scale disturbance pulses: A case study from sub-boreal forests of western Quebec (Canada). 2008. For. Ecol. Manage. 256(10):1734-1742.
DOI : 10.1016/j.foreco.2008.05.044
The northern Témiscamingue region (western Québec) sustained regional-scale pulses of natural disturbances during the 1850–2000 period, such as severe fires during the 1908–1926 period, two severe spruce budworm outbreaks that occurred in 1909–1918 and 1974–1984, and two birch dieback episodes around 1940 and 1980. These disturbances produced synchronous fluctuations in forest characteristics over large spatial scales. In this paper, we review possible responses of flora and fauna to pulsed large-scale disturbance events and speculate on whether they should be emulated to reduce the impacts of forest management on non-timber resources. The importance of large-scale disturbance pulses for biodiversity and forest ecosystem integrity is potentially great, but this aspect has been poorly investigated by previous research, and thus there is little information available to guide forest management. Large-scale, synchronous disturbances could be emulated by clustering harvesting activities in time, for example by creating “harvest pulses” of 10–20 years, separated by periods of 50–100 years or so with low harvest rates. A potential disadvantage of this strategy is that when our capacity to predict future natural disturbances is low, there is a higher probability of accidentally taking the forest ecosystem outside of the range of natural variability compared with a status quo forest management scenario. From a socio-economic perspective, another potential disadvantage is in creating irregular wood flows to the forest transformation industry. Nonetheless, in a context where the forest has been over-disturbed in the recent past, a forest management strategy involving fluctuating harvest rates could provide the means for faster ecosystem recovery compared with a status quo strategy. We recommend that the potential importance of disturbance pulses for boreal and sub-boreal ecosystems be more thoroughly investigated by future research to inform management and conservation policies. © Elsevier B.V. All rights reserved.
Mathieu Bouchard, Yves Bergeron, Daniel Kneeshaw. Forest dynamics after successive spruce budworm outbreaks in mixedwood forests. 2006. Ecology 87(9):2319-2329.
In order to assess the long-term spatiotemporal influence of the spruce
budworm in sub-boreal mixedwood forests, we studied the effect of three successive outbreaks
in a region of western Quebec, Canada. We used dendrochronology to detect past outbreaks in
three areas (111–185 ha), based on the recruitment age of balsam fir (Abies balsamea) and on
growth patterns of white spruce (Picea glauca), the two main host species of this defoliating
insect. We also used a series of aerial photographs taken between 1935 and 2003 to evaluate
overstory mortality and post-outbreak succession patterns in these same areas. Individual
outbreaks had a spatially homogenous impact on host species throughout the region, but
successive outbreaks differed in intensity: the two outbreaks around 1910 and 1980 caused
widespread mortality in the overstory, but an outbreak around 1945 had little impact,
probably because the forest mosaic had not yet recuperated from the 1910 outbreak. No clear
outbreak was detected in the later part of the 19th century. In portions of the study areas
where the 1910 outbreak had a major impact, between 36% and 50% of the stands were
reoccupied by balsam fir stands in the period up to the 1980 outbreak (cyclic succession), the
rest being at least partly replaced by nonhost species such as Betula spp. Changes in forest
composition after the 1910 outbreak were mostly associated with upper-slope positions in all
study areas. The 1980 outbreak also had a higher impact than earlier outbreaks in lower-slope
positions dominated by black spruce (Picea mariana)–balsam fir mixtures. These results
suggest that, at the regional scale, the abundance of mature or over-mature balsam fir stands
does not determine the outbreak cycle. When an outbreak occurs, however, its impact will be
strongly constrained by forest characteristics such as stand composition and structure, which
are themselves influenced by previous disturbances and slope position.
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Justine Gillis, Jonathan Boucher, Miguel Montoro Girona, Mathieu Bouchard. Impact des traitements de BTK contre la tordeuse des bourgeons de l'épinette sur les risques de feu dans un peuplement. 25e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2023-11-28)
Judicaël Osse, Yves Bergeron, Mathieu Bouchard, Élise Filotas, Marie-Josée Fortin, Rob Johns, Hubert Morin, Pierre Therrien, Marie-Eve Sigouin, François Lévesque , Anoj Subedi, Zinsou Max Debaly, Guillaume Tougas. Un défi boréal – Projections de l’activité de la tordeuse des bourgeons d’épinette (TBE) dans un contexte de changement climatique présenté dans le cadre du colloque La tordeuse des bourgeons de l'épinette : comprendre, prévoir, lutter.
Rendez-vous de la connaissance en aménagement forestier durable (2023-10-16)
Annie Belleau, Osvaldo Valeria, Daniela Mazo Calle, Vincent Nadeau, Mathieu Bouchard. L’utilisation du benchmarking pour guider les meilleures pratiques d’organisation spatiale de la récolte forestière Les Rendez-vous de la connaissance en aménagement forestier durable MFFP - Aménagement et récolte en forêt boréale (2021-06-01)
Janie Lavoie, Maxence Martin, Annie Deslauriers, Mathieu Bouchard, Joshua Jarry, Anne-Sophie Caron, Hubert Morin. Rendez-vous de la connaissance en aménagement forestier durable - Ravageurs forestiers Rendez-vous de la connaissance en aménagement forestier durable (2021-05-18)
Annie Belleau, Daniela Mazo Calle, Osvaldo Valeria, Mathieu Bouchard, Pierre Couture. Comparaison de l'effet d’organisation spatiale de la récolte forestière sur la performance financière en utilisant l'Analyse d'enveloppement des données (DEA) 21e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2019-11-30)
Philippe Marchand, Miguel Montoro Girona, Mathieu Bouchard, Élise Filotas, Hubert Morin, Louis De Grandpré, Yves Bergeron, Pierre Therrien, Anouschka R. Hof, Matthew Duveneck. Projections de l’activité de la tordeuse des bourgeons de l’épinette dans un contexte de changement climatique 21e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2019-11-30)
Marin Seto, Jean-Pierre Jetté, Alexis Schab, Tadeusz Splawinski, Dominic Cyr, Sonia Légaré, Véronique Christophe, Alexis Leroux, Mathieu Bouchard, Yan Boucher, Jean-Pierre Saucier, Alain Leduc, Osvaldo Valeria, Sylvie Gauthier, Yves Bergeron. La gestion du risque intégrée à la prise de décision en aménagement forestier: le cas des zones sensibles de la forêt boréale. Carrefour Forêts (2019-04-04)
Mathieu Bouchard Modélisation des perturbations naturelles et marges de variabilité pour les forêts du Québec Midi-foresterie (2014-03-11)
Mathieu Bouchard à déterminer Axe écologie (2011-02-09)
Mathieu Bouchard Dynamique des forêts surannées du Nord du Témiscamingue. Soutenance thèse (2005-09-02)
Mathieu Bouchard, Daniel Kneeshaw, Yves Bergeron. Natural dynamics following successive spruce budworm outbreaks in mixed forests of western Quebec (Canada) 5th international Workshop on Disturbance Dynamics in Boreal forests, Dubna, Russie.
Mathieu Bouchard Forest landscape composition and structure after successive spruce budworm outbreaks 5thNorth American Forest Ecology Workshop, Aylmer, Québec, Canada.
Mathieu Bouchard Le rôle de la tordeuse des bourgeons de l’épinette dans la dynamique forestière au Témiscamingue 71ième congrès annuel de l’ACFAS. Université du Québec à Rimouski, Québec, Canada.
