Yves Bergeron

• Phd
• Professor (emeritus) at Université du Québec en Abitibi-Témiscamingue

In Canada, clearcutting is the most widely used silvicultural system in boreal forests despite potential impacts on forest simplification and biodiversity loss. Retaining mature trees is suggested to maintain stand structure and biodiversity, especially for promoting the regeneration of shade-tolerant species. Partial harvesting is considered a pro...

Les feux de forêt façonnent les écosystèmes boréaux et altèrent les environnements aquatiques en modifiant le transport des sédiments et des nutriments vers les lacs, ce qui affecte la qualité de l’eau et l’écologie des lacs. Le changement climatique pourrait augmenter la fréquence et la sévérité des feux, ainsi que le stress sur les écosystèmes aq...

This study investigates the distribution of subfossil chironomid assemblages in surface sediments from 182 lakes in New England and Eastern Canada, aiming to develop a new summer paleotemperature transfer function across an extended latitudinal gradient. Canonical analyses reveal a strong empirical relationship between chironomid taxa and summer te...

Spatially explicit reconstructions of fire activity in northwestern boreal Canada are rare, despite their importance for modeling current and future disturbance regimes and forest dynamics. We provide a dendrochronological reconstruction of historical fire activity along Highway 3 in the Northwest Territories (NWT), Canada, within the boreal subarc...

45e colloque annuel du Centre d'Études Nordiques (CEN), Université du Québec à Trois-Rivières

Context The vegetation composition of northeastern North American forests has significantly changed since pre-settlement times, with a marked reduction in conifer-dominated stands, taxonomic and functional diversity. These changes have been attributed to fire regime shifts, logging, and climate change. Methods In this study, we disentangled the in...

Following deglaciation, lowland sites in eastern Canada that were covered by proglacial Lake Ojibway recorded direct afforestation with boreal mixedwood taxa, without an initial tundra phase, contrary to sites that were never covered by this lake. Because former islands of proglacial Lake Ojibway were colonized by vegetation before lake drainage ar...

The characteristics of the frost regime (intensity, frequency, and timing) contribute to shaping tree species adaptations and distribution as well as ecosystem productivity and functions. However, climate change increases the variability in extreme events; therefore, the different characteristics of the frost regime may diverge under climate change...

The mosaic of tree structure and composition in the boreal mixedwood forest of western Quebec has been primarily shaped by natural disturbances and climate changes over time. Extensive research has focused on long-term fire-vegetation interactions, particularly in lowlands that were submerged by Lac Ojibway approximately 8,200 years ago. In contras...

The fundamental trade‐off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain very rare and we lack a global view on the generality and the shape...

Partial cutting has lower canopy removal intensities than clearcutting and has been proposed as an alternative harvesting approach to enhance ecosystem services, including carbon sequestration and storage. However, the ideal partial cutting/clearcutting proportion that should be applied to managed areas of the eastern Canadian boreal forest to enha...

La saison des feux de forêt de 2023 au Québec, marquée par des conditions extrêmement chaudes et sèches, a établi de nouveaux records en brûlant 4,5 millions d'hectares. Cette situation est directement liée aux impacts persistants et en augmentation du changement climatique. Cette étude examine les conditions météorologiques exceptionnelles ayant m...

The Canadian 2023 forest fire season has been of such magnitude that it forces us to think deeply about forest management as it is currently practiced in the Canadian boreal forest. As similar events are likely to recur in upcoming years, we must reflect on management practices to better cope with these risks and mitigate their consequences. Focuss...

La saison des incendies forestiers au Canada en 2023 a été d’une telle ampleur qu’elle force une réflexion profonde au sujet de l’aménagement forestier tel qu’il est pratiqué actuellement dans la forêt boréale canadienne. Comme des événements similaires sont susceptibles de se reproduire dans les années à venir, nous devons réfléchir à des pratique...

Partial cutting has lower canopy removal intensities than clearcutting and has been proposed as an alternative harvesting approach to enhance ecosystem services, including carbon sequestration and storage. However, the ideal partial cutting/clearcutting proportion that should be applied to managed areas of the eastern Canadian boreal forest to enha...

Extreme weather events are expected to increase in frequency and intensity in South America, likely causing decreased plant productivity and altering species distributions. Yerba mate (Ilex paraguariensis) is a tree species native to South America and has an ecological, social, and economic importance in several countries. Natural forests and culti...

Climate change (CC) necessitates reforestation/afforestation programs to mitigate its impacts and maximize carbon sequestration. But comprehending how tree growth, a proxy for fitness and resilience, responds to CC is critical to maximize these programs' effectiveness. Variability in tree response to CC across populations can notably be influenced...

The 2023 wildfire season in Québec set records due to extreme warm and dry conditions, burning 4.5 million hectares and indicating persistent and escalating impacts associated with climate change. This study reviews the unusual weather conditions that led to the fires, discussing their extensive impacts on the forest sector, fire management, boreal...

Les caractéristiques des forêts préindustrielles permettent d’établir des états de référence pour l'aménagement durable des forêts. Cette approche historique est particulièrement pertinente pour les régions soumises à une forte influence humaine, dans lesquelles les forêts naturelles sont rares. C'est le cas de la région de Rouyn-Noranda, à l'ouest...

The hemi-boreal zone, marking North America’s southern boreal forest boundary, has evolved post-glaciation, hosting diverse ecosystems including mixed forests with savannas, grasslands, and wetlands. While human, climate, and fire interactions shape vegetation dynamics therein, specific influences remain unclear. Here we unveil 12,000 years of hemi...

1 Ingénieur forestier indépendant 2 Professeur associé, Centre d'étude de la forêt, UQAM 3 Chercheure émérite, Ressources Naturelles Canada 4 Professeur émérite, UQAM-UQAT Résumé : La saison des feux de forêt au Canada en 2023 a été d'une telle ampleur qu'elle nous oblige à réfléchir profondément à la gestion forestière telle qu'elle est pratiquée...

Aim Seedling recruitment is a vital process for forest regeneration and is influenced by various factors such as stand composition, climate, and soil disturbance. We conducted a long‐term field experiment (18 years) to study the effects of these factors and their interactions on seedling recruitment. Location Our study focused on five main species...

Climate, soil, and competition factors jointly drive tree growth variability at local and regional scale. However, the comprehensive interaction of these factors and their combined effects on tree responses within their environment remains poorly explored in current research. Using a detailed forest inventory dataset in Québec, we examined tree gro...

The 2023 wildfire season in Québec set records due to extreme warm and dry conditions, burning 4.5 million hectares and indicating persistent and escalating impacts associated with climate change. The study reviews the unusual weather conditions that led to the fires, discussing their extensive impacts on the forest sector, fire management, boreal...

Supplementary information to support the article of Sayedi et al. 2024, Fire Ecology.

Background The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable ma...

Roads are known to alter environmental conditions and the composition of road edge plant communities, particularly when exogenous materials are used as road surfacing. In this study, we evaluate the impact of gravel roads on the organic layer thickness (OLT) and aspen distribution in a boreal forest landscape of Eastern Canada. The OLT and aspen di...

Black spruce (Picea mariana (Mill.) B.S.P.) is the dominant conifer species across a large part of North American boreal forests, providing many goods and services essential to human activities, and playing a major climatic role through the global carbon cycle. However, a comprehensive synthesis of the effects of climate change on black spruce has...

In eastern Canada, boreal forests are locally experiencing a shift between two alternative stable states, productive closed-canopy feather moss (Pleurozium schreberi (Brid.) Mitt.) forests to low-productivity open lichen (Cladonia spp.) woodlands. While this shift has important consequences for ecosystem structure and productivity, little is known...

Edge habitats resulting from the construction and maintenance of forest roads favour pioneer, shade-intolerant and disturbance-adapted plant species. The effect of roads on the spread of non-native species has been frequently studied, but few studies have focused upon their effects on native tree species. We studied the effect of forest roads on th...

The eastern, maritime portion of the black spruce-moss bioclimatic domain in Québec (Canada) is characterized by large wildfires with low occurrence. However, it is still poorly understood how climate-fire interactions influenced long-term vegetation dynamics in the boreal forest of eastern Québec. The long-term historical climate-fire-vegetation i...

Professeur émérite en écologie et aménagement forestier (UQAM) et professeur associé (UQAT) Sylvie Gauthier-Chercheure émérite à Ressources naturelles Canada Alain Leduc-Professeur associé au Centre d'étude de la forêt à l'UQAM Jean-Pierre Jetté, ingénieur forestier La saison des incendies forestiers que nous venons de connaître a été d'une telle a...

This study aimed to understand the above- and belowground community assembly in subtropical plantations, and to detect the relationship with understory plant communities, soil microbial communities and stocks of soil organic carbon, nitrogen and phosphorus. We compared the composition and diversity of understory plants and microbial communities amo...

Severe drought is expected to increase in frequency and intensity in South America, likely causing decreased plant productivity and altering species distributions. Yerba mate ( Ilex paraguariensis ) is a tree species native to South America and has an ecological, social, and economic importance in several countries. Natural forests and cultivated a...

Boreal ecosystems are composed with numerous lakes of various shapes and sizes, some of which are composed of islands. Forested islands form forest-lake interfaces conducive to unique vegetation processes and disturbance dynamics. However, the role of forest structure and disturbance dynamics on islands environments and biodiversity has been little...

À l’est du Canada, la forêt tempérée mixte abrite le pin blanc (Pinus strobus L.) et le pin rouge (Pinus resinosa Ait.), deux conifères endémiques d’importance économique, écologique, et culturelle. Depuis le début du XXe siècle, les pinèdes rouges et blanches déclinent en raison de l’exploitation forestière, des pathogènes et des changements clima...

Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism‐resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species. We synthesized global trait and v...

Climate change poses a serious risk to sustainable forest management, particularly in boreal forests where natural disturbances have been projected to become more severe. In three Quebec boreal forest management units, biomass carbon storage under various climate change and management scenarios was projected over 300 years (2010–2310) with a proces...

Sugar maple (Acer saccharum Marshall) growth in the species’ southern range has been declining since the 1980s, putting at risk a variety of ecosystem services that the species provides. Heatwaves, drought, frosts, acidic deposition, and insect defoliation, all reducing photosynthetic activity, have been suggested to be behind the phenomenon. Becau...

Study region: In northwestern Québec, the Upper Harricana River is representative of the Abitibi Plains’ hydrological dynamics over the last 250 years. Study focus: Planning for future spring flood risks involves uncertainties. This research presents a multicentury evaluation of changes in spring mean discharge and flood drivers using streamflow re...

An isolated sugar maple ( Acer saccharum Marsh.) stand is located in the boreal forest of Abitibi, about 75 km beyond its present northern range limit. When did this relatively thermophilous tree species establish after ice retreat? Were its populations more abundant than now sometimes in the past? If so, when and how did they expand then retracted...

The benefits of masting (volatile, quasi-synchronous seed production at lagged intervals) include satiation of seed predators, but these benefits come with a cost to mutualist pollen and seed dispersers. If the evolution of masting represents a balance between these benefits and costs, we expect mast avoidance in species that are heavily reliant on...

Alternative states defined by tree‐canopy dominance result in different ecosystem functioning and shape habitat conditions for the understory vegetation. One example in the boreal forest is the alternation between broadleaf deciduous and coniferous forests. Disturbances related to natural fires and human land uses have produced changes in tree‐cano...

Trembling aspen (Populus tremuloïdes) is the most widely distributed fast-growing tree species in the eastern Canadian boreal mixed forest. The ability of this species to invade disturbed environments is related to its ability to reproduce easily by suckering. This phenomenon whereby genetically identical individuals appear in a clonal way could le...

Logging has existed for many centuries in boreal countries where forestry is a major economic force in Canada. Forestry companies were the first to settle in many regions, even preceding colonization (e.g. in the Abitibi-Témiscamingue (Quebec)). In the 19th century, the main objective of forestry in Abitibi was to extract wood from the forest and t...

Many studies have focused on vegetation across forest edges to study impacts of edges created by human activities on forest structure and composition, or patterns of vegetation at inherent natural edges. Our objective was to create a database of plant‐related variables across different types of edges from various studies (mainly from across Canada,...

Current ecological models predict profound climate change-related effects on the natural disturbance regimes of forests. Spruce budworm (Choristoneura fumiferana) (SBW) is the principal insect defoliator in eastern North America, and SBW outbreaks have a major impact on the structure and function of the Canadian boreal forest, as defoliation leads...

The exceptional ecological and social value of the world’s old-growth forests is undeniable, although disagreements and conflicts about their future persist. The many ecological, economic, cultural, recreational and spiritual ecosystem services that these forests provide explain the interest placed in them. In addition, there is a great concern in...

At the end of the last glacial period in the northern hemisphere, meltwater from receding ice sheets accumulated into large proglacial lakes, potentially limiting postglacial afforestation. We explored whether former islands of proglacial Lake Ojibway (Canada) (hilltops in the current landscape) could have acted as migration outposts and thus accel...

Dry and warm conditions have exacerbated the occurrence of large and severe wildfires over the past decade in Canada’s Northwest Territories (NT). While temperatures are expected to increase during the 21st century, we lack understanding of how the climate- vegetation-fire nexus might respond. We used a dynamic global vegetation model to project an...

Climate change is having complex impacts on the boreal forest, modulating both tree growth limiting factors and fire regime. However, these aspects are usually projected independently when estimating climate change effect on the boreal forest. Using a combination of three different methods, our goal is to assess the combined impact of changes in gr...

Regional analyses assessing the vulnerabilities of forest ecosystems and the forest sector to climate change are key to considering the heterogeneity of climate change impacts as well as the fact that risks, opportunities, and adaptation capacities might differ regionally. Here we provide the Regional Integrated Assessment of climate change on Queb...

Rare habitats result from the geochemistry, history, or topography of the environment. They shelter regionally rare species (i.e., those with only a few mentions) and are threatened by global changes and human activities. On the clay plains of western Québec, the scattered highest hills emerged from the proglacial lake Ojibway (10,200–8200 BP) as i...

Background and aims Low productivity open lichen (Cladonia spp.) woodlands have been rapidly expanding in the closed-crown feather moss (Pleurozium schreberi (Brid.) Mitt.) boreal forest of eastern Canada. While open-woodland areas are progressing, there is little information on the recoverability of open lichen woodlands back to closed-canopy fore...

Background and aims Low productivity open lichen (Cladonia spp.) woodlands have been rapidly expanding in the closed-crown feather moss (Pleurozium schreberi (Brid.) Mitt.) boreal forest in eastern Canada. While open-woodland areas are progressing, there is little information on the recoverability of open lichen woodlands back to closed-canopy fore...

This open access book explores a new conceptual framework for the sustainable management of the boreal forest in the face of climate change. The boreal forest is the second-largest terrestrial biome on Earth and covers a 14 million km2 belt, representing about 25% of the Earth’s forest area. Two-thirds of this forest biome is managed and supplies 3...

Clear-cutting has been the dominant harvesting method used in boreal forest silviculture. Reducing the potential negative effects of intensive forestry activities on ecosystems, e.g., the simplification and homogenization of stand structure, requires diversifying silvicultural practices to promote forest resilience in the face of climate change. Pr...

Long-term disturbance histories, reconstructed using diverse paleoecological tools, provide high-quality information about pre-observational periods. These data offer a portrait of past environmental variability for understanding the long-term patterns in climate and disturbance regimes and the forest ecosystem response to these changes. Paleoenvir...

The boreal forest is a vast biome encompassing approximately one-third (30%) of the world’s forest area. It harbors about half of the world’s remaining natural and near-natural forests and provides important ecological, economic, social, and cultural services and values that benefit human communities (Burton et al., 2010; Gauthier et al., 2015a). A...

Purpose Natural and anthropogenic causes have produced changes in tree dominance from coniferous to broadleaf deciduous forests, generating shifts in litter inputs and plant understory composition. The impact of changes in canopy-associated factors on belowground microbial communities remain poorly understood. The objective of this study was to bet...

Aim Our understanding of the mechanisms that maintain forest diversity under changing climate can benefit from knowledge about traits that are closely linked to fitness. We tested whether the link between traits and seed number and seed size is consistent with two hypotheses, termed the leaf economics spectrum and the plant size syndrome, or whethe...

With climate change, climatic optima are shifting poleward more rapidly than tree migration processes, resulting in a mismatch between species distributions and bioclimatic envelopes. Temperate hardwood tree species may take advantage of the release of climate constraints and forest management to migrate into the boreal forest. Here, we use the SOR...

Several recent studies point out that climate change is expected to influence boreal forest succession, disturbances, productivity, and mortality. However, the effect of climate change on those processes and their interactions is poorly understood. We used an ecophysiological-based mechanistic landscape model to study those processes and their inte...

Human activity has fundamentally altered wildfire on Earth, creating serious consequences for human health, global biodiversity, and climate change. However, it remains difficult to predict fire interactions with land use, management, and climate change, representing a serious knowledge gap and vulnerability. We used expert assessment to combine op...

Logging has existed for many centuries in boreal countries where forestry is a major economic force in Canada. Forestry companies were the first to settle in many regions, even preceding colonization (e.g. in the Abitibi-Témiscamingue (Quebec)). In the 19th century, the main objective of forestry in Abitibi was to extract wood from the forest and t...

Despite growing interest in predicting plant phenological shifts, advanced spring phenology by global climate change remains debated. Evidence documenting either small or large advancement of spring phenology to rising temperature over the spatio-temporal scales implies a potential existence of a thermal threshold in the responses of forests to glo...

Thuja occidentalis L. wood is desirabl, e for wooden structures that require wood density uniformity. Wood density is a wood quality indicator related to numerous morphological, mechanical, physiological, and ecological properties. This study aimed to investigate the regional, site, and tree-to-tree variations of T. occidentalis wood density and gr...

Warning This article contains terms, descriptions, and opinions used for historical context that may be culturally sensitive for some readers. Background Understanding drivers of boreal forest dynamics supports adaptation strategies in the context of climate change. Aims We aimed to understand how burn rates varied since the early 1700s in North...

Purpose: Natural and anthropogenic causes have produced changes in tree dominance from coniferous to broadleaf deciduous forests, generating shifts in litter inputs and plant understory composition. The impact of changes in canopy-associated factors on belowground microbial communities remain poorly understood. The objective of this study was to be...

In boreal forests in Canada, broadleaf stands are characterized by generally well-drained soils and a humus-rich layer. In contrast, spruce-moss stands are often characterized by more poorly drained soils and acidic humus layer. However, presence of these two forest types in various degrees of mixture in stands can be beneficial to spruce seedlings...

Over the past decades, the abundance and area of macrocharcoal (i.e. ≥ 150 μm in diameter) fragments from sedimentary sequences have been quantified using visual or semi-automated methods to reconstruct fire histories. However, the lack of uniformity between counting methods used in each study could introduce methodological biases influencing fire...

Avalaible online : https://couvertboreal.com/publications/automne-2022/