Indigenous knowledge, forest landscape modeling, and the cumulative effects of environmental changes.

Boreal landscapes are exposed to climate change, forestry, and other industrial stressors with consequences for Indigenous people's wellbeing and relationship with traditional lands. As a collaborative and transdisciplinary research team including researchers and students from universities, Indigenous communities, and government and non-government organizations, we addressed the consequences of these environmental changes for an Eeyou (Cree) community and an Anishnaabe community in Eastern boreal Canada (Quebec). Our aims were to (1) develop a landscape value model combining qualitative and quantitative data as well as knowledge from Indigenous land-use experts and forest landscape simulations; (2) evaluate the vulnerability of Indigenous landscape values to environmental changes; and (3) assess the relative importance of climate change and forestry as drivers of environmental changes.

Climate is stronger than you think: Exploring functional planting and TRIAD zoning for increased forest resilience to extreme disturbances.

In the face of global changes, forest management must now consider adapting forests to novel and uncertain conditions alongside objectives of conservation and production. In this perspective, we modified the TRIAD zoning approach to add a resilience component through functionally diverse plantations following harvesting in the extensive areas. We then assessed the capacity of this new "TRIAD+" zoning approach for improving the resilience of the mature forest biomass to climate change and three potential extreme pulse disturbances: a large fire, a severe drought, and an insect outbreak.

Timber harvesting was the most important factor driving changes in vegetation composition, as compared to climate and fire regime shifts, in the mixedwood temperate forests of Temiscamingue since AD 1830.

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 individual effects of these drivers on the forest composition in southwestern Quebec from 1830 to 2000 by conducting retrospective modelling using the LANDIS-II forest landscape model.

Human driven climate change increased the likelihood of the 2023 record area burned in Canada.

In 2023, wildfires burned 15 million hectares in Canada, more than doubling the previous record. These wildfires caused a record number of evacuations, unprecedented air quality impacts across Canada and the northeastern United States, and substantial strain on fire management resources. Using climate models, we show that human-induced climate change significantly increased the likelihood of area burned at least as large as in 2023 across most of Canada, with more than two-fold increases in the east and southwest.

Drivers and Impacts of the Record-Breaking 2023 Wildfire Season in Canada.

The 2023 wildfire season in Canada was unprecedented in its scale and intensity, spanning from mid-April to late October and across much of the forested regions of Canada. Here, we summarize the main causes and impacts of this exceptional season. The record-breaking total area burned (~15 Mha) can be attributed to several environmental factors that converged early in the season: early snowmelt, multiannual drought conditions in western Canada, and the rapid transition to drought in eastern Canada.

Effect of a severe cold spell on overwintering survival of an invasive forest insect pest.

Cold temperatures can play a significant role in the range and impact of pest insects. Severe cold events can reduce the size of insect outbreaks and perhaps even cause outbreaks to end. Measuring the precise impact of cold events, however, can be difficult because estimates of insect mortality are often made at the end of the winter season.

How will climate change and forest harvesting influence the habitat quality of two culturally salient species?

Boreal landscapes face increasing disturbances which can affect cultural keystone species, i.e. culturally salient species that shape in a major way the cultural identity of a people.

The umbrella value of caribou management strategies for biodiversity conservation in boreal forests under global change.

Single-species conservation management is often proposed to preserve biodiversity in human-disturbed landscapes. How global change will impact the umbrella value of single-species management strategies remains an open question of critical conservation importance. We assessed the effectiveness of threatened boreal caribou as an umbrella for bird and beetle conservation under global change.

Climate change alone cannot explain boreal caribou range recession in Quebec since 1850.

The contraction of species range is one of the most significant symptoms of biodiversity loss worldwide. While anthropogenic activities and habitat alteration are major threats for several species, climate change should also be considered. For species at risk, differentiating the effects of human disturbances and climate change on past and current range transformations is an important step towards improved conservation strategies.

Lowering the rate of timber harvesting to mitigate impacts of climate change on boreal caribou habitat quality in eastern Canada.

Many boreal populations of woodland caribou (Rangifer tarandus caribou) have declined in Canada, a trend essentially driven by the increasing footprint of anthropogenic disturbances and the resulting habitat-mediated apparent competition that increases predation pressure. However, the influence of climate change on these ecological processes remains poorly understood. We evaluated how climate change will affect boreal caribou habitat over the 2030-2100 horizon and in a 9.

Short- and long-term wildfire threat when adapting infrastructure for wildlife conservation in the boreal forest.

Managers designing infrastructure in fire-prone wildland areas require assessments of wildfire threat to quantify uncertainty due to future vegetation and climatic conditions. In this study, we combine wildfire simulation and forest landscape composition modeling to identify areas that would be highly susceptible to wildfire around a proposed conservation corridor in Québec, Canada. In this measure, managers have proposed raising the conductors of a new 735-kV hydroelectric powerline above the forest canopy within a wildlife connectivity corridor to mitigate the impacts to threatened boreal woodland caribou (Rangifer tarandus).

Multi-model projections of tree species performance in Quebec, Canada under future climate change.

Many modelling approaches have been developed to project climate change impacts on forests. By analysing 'comparable' yet distinct variables (e.g.

Sequential droughts: A silent trigger of boreal forest mortality.

Despite great concern for drought-driven forest mortality, the effects of frequent low-intensity droughts have been largely overlooked in the boreal forest because of their negligible impacts over the short term. In this study, we used data from 6876 permanent plots distributed across most of the Canadian boreal zone to assess the effects of repeated low-intensity droughts on forest mortality. Specifically, we compared the relative impact of sequential years under low-intensity dry conditions with the effects of variables related to the intensity of dry conditions, stand characteristics, and local climate.

Current and projected cumulative impacts of fire, drought, and insects on timber volumes across Canada.

Canada's forests are shaped by disturbances such as fire, insect outbreaks, and droughts that often overlap in time and space. The resulting cumulative disturbance risks and potential impacts on forests are generally not well accounted for by models used to predict future impacts of disturbances on forest. This study aims at projecting future cumulative effects of four main natural disturbances, fire, mountain pine beetle, spruce budworm and drought, on timber volumes across Canada's forests using an approach that accounts for potential overlap among disturbances.

Model-specification uncertainty in future forest pest outbreak.

Climate change will modify forest pest outbreak characteristics, although there are disagreements regarding the specifics of these changes. A large part of this variability may be attributed to model specifications. As a case study, we developed a consensus model predicting spruce budworm (SBW, Choristoneura fumiferana [Clem.

Fire regime zonation under current and future climate over eastern Canada.

Fire is a major disturbance in Canadian forests. Along with fuel and ignition characteristics, climatic conditions are seen as one of the main drivers of fire regimes. Projected changes in climate are expected to significantly influence fire regimes in Canada.

Distribution patterns of three long-horned beetles (Coleoptera: Cerambycidae) shortly after fire in boreal forest: adults colonizing stands versus progeny emerging from trees.

We identified the factors that affect the early colonization of burned stands by adults and the progeny surviving in fire-killed black spruce trees for three cerambycid beetles: Acmaeops proteus proteus (Kirby), Acmaeops pratensis (Laicharting), and Monochamus scutellatus scutellatus (Say) (Coleoptera: Cerambycidae) in the northern Canadian boreal forest. Furthermore, we measured if progeny emerging from burned trees was related to patterns of adults captured in traps the same year as the fire. Fire severity at the stand and landscape scales were the most important predictors for colonizing adults.

Postfire succession of saproxylic arthropods, with emphasis on coleoptera, in the north boreal forest of Quebec.

Saproxylic succession in fire-killed black spruce [Picea mariana (Mill.) B.S.