Jérôme Laganière

Natural Resources Canada | NRCan · Canadian Forest Service

Non-native earthworms have been invading North America since European settlement. Compared to temperate forests, their presence in the boreal forest is much more recent and thus remains understudied, despite the potential threat they represent for soil carbon (C) stocks. Here we compared earthworm-invaded and earthworm-free zones in soil types repr...

The maintenance of the large soil organic carbon (SOC) stocks of the boreal forest under climate change is a matter of concern. In this study, major soil carbon pools and fluxes were assessed in 22 closed-canopy forests located along an elevation and latitudinal climatic gradient expanding 4 ∘C in mean annual temperature (MAT) for two important bor...

Forest bioenergy production can represent a renewable energy supply while benefiting the forest sector. However, GHG reductions are often not immediate. The point of carbon parity where bioenergy starts delivering GHG benefits may be years-to-decades in the future. This study examines the life-cycle emissions associated with bioenergy production at...

Earthworm invasion in North American forests has the potential to greatly impact soil microbial communities by altering soil physicochemical properties, including structure, pH, nutrient availability, and soil organic matter (SOM) dynamics. While most research on the topic has been carried out in northern temperate forests, little is known on the i...

Stable isotope ratios of soil organic carbon (SOC) are a potentially powerful, integrative tool for analyzing the soil C cycle. However, limited understanding of the mechanisms for C isotope fractionation in soil prevents their widespread application. Soil organic carbon (SOC) is progressively enriched in 13C with age and depth in the soil profile...

As anthropogenic nitrogen (N) emissions have been rising for decades, it is critical to develop natural archives that help understand how natural processes were modified in the past. Tree-ring δ¹⁵N values may represent such an indicator but its validity as faithful record of N cycling changes is still debated. Here we produce long-tree-ring δ¹⁵N se...

La séquestration du carbone (C) dans le sol fait partie des solutions pour atténuer les changements climatiques. Les arbres à croissance rapide constituent un outil potentiel dans ce contexte puisqu’ils accumulent rapidement du C dans leur biomasse et pourraient transférer davantage de matière organique dans le sol. Toutefois, l’impact de la produc...

The maintenance of the large soil organic carbon (SOC) stocks of the boreal forest under climate change is a matter of concern. In this study, major soil carbon pools and fluxes were assessed in twenty-two closed-canopy forests located along an elevation and latitudinal climatic gradient expanding 4 °C in mean annual temperature (MAT) for two impor...

Remote and northern communities surrounded by forested areas are well positioned to use wood-based bio-energy to meet their energy needs and thereby reduce their greenhouse gas (GHG) emissions. However major gaps remain regarding the GHG mitigation potential considering the challenges along the biomass supply chain. Using Fort McPherson, an Indigen...

Using diesel in remote off-grid communities creates many environmental, health, and economic issues. Remote communities surrounded by forested areas could use bioenergy to meet their energy needs, however gaps remain regarding the GHG mitigation potential of switching from diesel to bioenergy .The aim of this study is to determine the potential to...

Determining controls on the temperature sensitivity of heterotrophic soil respiration remains critical to incorporating soil–climate feedbacks into climate models. Most information on soil respiratory responses to temperature comes from laboratory incubations of isolated soils and typically subsamples of individual horizons. Inconsistencies between...

The ability of plantations to provide ecosystem services relies on interdependent actions, notably the control of competing vegetation to provide planted seedlings with adequate resource levels. While short-term results from silviculture trials can inform about resource acquisition and use by planted seedlings during the establishment phase, longer...

Anthropogenic N emissions represent a potential threat for forest ecosystems, and environmental indicators that provide insight into the changing forest N cycle are needed. Tree ring N isotopic ratios (δ¹⁵N) appear as a contentious choice for this role as the exact mechanisms behind tree-ring δ¹⁵N changes seldom benefit from a scrutiny of the soil-...

Determining controls on the temperature sensitivity of heterotrophic soil respiration remains critical to incorporating soil-climate feedbacks into climate models. Most information on soil respiratory responses to temperature come from laboratory incubations of isolated soils, and typically subsamples of individual horizons. Inconsistencies between...

Almost half of the total organic carbon (C) in terrestrial ecosystems is stored in forest soils. By altering rates of input or release of C from soils, forest management activities can influence soil C stocks in forests. In this review, we synthesize current evidence regarding the influences of 13 common forest management practices on forest soil C...

Displacement of fossil fuels by forest bioenergy can contribute to climate change mitigation by reducing greenhouse gas (GHG) emissions. However, GHG savings are not realised until the avoided fossil emissions offset the loss of atmospheric carbon (C) that would have been sequestered if the biomass was not used for bioenergy (i. e. time to C seques...

Globally increasing anthropogenic airborne emissions of reactive nitrogen (N) generate several environmental issues that require investigating how N accumulation modifies the N cycle. Tree-ring δ ¹⁵ N series may help understanding past and current perturbations in the forest N cycle. Although several studies have addressed this issue, most of them...

AshNet is a network of Canadian government, academic, and industry researchers, foresters and policy makers investigating the potential beneficial diversion of wood ash, a by-product of the growing bioenergy industry, from landfills across Canada to forest soils. AshNet currently consists of 14 wood ash application experiments established at sites...

AshNet est un réseau de représentants du gouvernement du Canada, d’universitaires, de chercheurs de l’industrie, de forestiers et de décideurs politiques qui étudient les avantages potentiels d’utiliser les cendres de bois, issue de l’industrie grandissante de la bioénergie et normalement envoyée dans les centres d’enfouissement au Canada, pour ame...

Driven by the policy imperatives of mitigating greenhouse gas (GHG) emissions and improving energy security, an increasing proportion of global energy demand is being met by nonfossil energy sources. The socioeconomic and environmental benefits of replacing fossil fuels with bioenergy are complex; however, debate continues about issues such as best...

Trembling aspen covers a large geographic range in North America, and previous studies reported that a better understanding of its singular influence on soil properties and processes is of high relevance for global change questions. Here we investigate the potential impact of a shift in aspen abundance on soil carbon sequestration and soil carbon s...

Climate warming enhances multiple ecosystem C fluxes, but the net impact of changing C fluxes on soil organic carbon (SOC) stocks over decadal to centennial time scales remains unclear. We investigated the effects of climate on C fluxes and soil C stocks using space-for-time substitution along a boreal forest climate gradient encompassing spatially...

The use of forest-based bioenergy to replace fossil fuels in heat and electricity generation has the potential to reduce greenhouse gas (GHG) emissions. Under sustainable forest management practices, forests can provide renewable feedstock for bioenergy as the CO2 released during wood combustion is later recaptured by photosynthesis as the forest r...

Accurately assessing the delay before the substitution of fossil fuel by forest bioenergy starts having a net beneficial impact on atmospheric CO2 is becoming important as the cost of delaying GHG emission reductions is increasingly being recognised. We documented the time to carbon (C) parity of forest bioenergy sourced from different feedstocks (...

Rethinking the Forest Industry requires better characterisation, quantification, and localisation of the forest biomass...

Rethinking the Forest Industry requires better characterisation, quantification ,and localisation of the forest biomass

Soil microbial biomass is a key source of soil organic carbon (SOC), and the increasing proportion of microbially derived SOC is thought to drive the enrichment of 13 C during SOC decomposition. Yet, little is known about how the d 13 C of soil microbial biomass differs across space or time, or with the composition of the microbial community. Varia...

Freeze-thaw (FT) cycles stimulate soil nitrogen (N) and carbon (C) mineralization, which may induce nitrous oxide (N2O) emissions. We examined how soybean (Glycine max L.) and corn (Zea mays L.) residue incorporation affect N2O emissions from high C content (35 g kg-1) silty clay and low C content (19 g kg-1) sandy loam soils over eight 10-d FT cyc...

Changes in forest composition as a result of forest management, natural disturbances, and climate change may affect the accumulation of soil organic carbon (SOC). We examined the influence of common boreal tree species (trembling aspen, black spruce, and jack pine), either in pure stands or in conifer-broadleaf mixtures, on the amount, distri-butio...

1. Although fine roots (< 2 mm in diameter) account for a major share of the production of terrestrial ecosystems, diversity effects on fine root productivity and their mechanisms remain unclear. 2. We hypothesized that: (i) fine root productivity increases with tree species diversity, (ii) higher fine root productivity is a result of greater soil...

Improving knowledge on the dynamics and maintenance of the boreal soil's C pool is of particular importance in response to climate change concerns. We hypothesized that different forest types (black spruce, trembling aspen, and mixedwood) found on a similar site type differentially affect soil organic carbon (SOC) distribution among physical fracti...

Processes governing tree interspecific interactions, such as facilitation and competition, may vary in strength over time. This study tried to unveil them by performing dendrometrical analyses on black spruce Picea mariana, trembling aspen Populus tremuloides and jack pine Pinus banksiana trees from pure and mixed mature boreal forest stands in the...

Litter quality is often considered the main driver of decomposition rate. The objective of this study was to investigate the relative contribution of two other tree-driven mechanisms, litter mixing and forest floor conditions, to foliar litter decomposition and nutrient dynamics for trembling aspen (Populus tremuloides Michx.) and black spruce (Pic...

Deforestation usually results in significant losses of soil organic carbon (SOC). The rate and factors determining the recovery of this C pool with afforestation are still poorly understood. This paper provides a review of the influence of afforestation on SOC stocks based on a meta-analysis of 33 recent publications (totaling 120 sites and 189 obs...

The occurrence of aspen (Populus tremuloides Michx.) patches within stands dominated by black spruce (Picea mariana Mill. BSP) has been shown to increase litter decomposition and nutrient cycling rates by improving soil physical and chemical properties. It is well known, however, that these processes are also influenced by the structure of the soil...