Black spruce
View article: Increasing fire and the decline of fire adapted black spruce in the boreal forest
Increasing fire and the decline of fire adapted black spruce in the boreal forest Open
Significance Black spruce is the dominant tree species in boreal North America and has shaped forest flammability, carbon storage, and other landscape processes over the last several thousand years. However, climate warming and increases i…
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The influence of vegetation and soil characteristics on active‐layer thickness of permafrost soils in boreal forest Open
Carbon release from thawing permafrost soils could significantly exacerbate global warming as the active‐layer deepens, exposing more carbon to decay. Plant community and soil properties provide a major control on this by influencing the m…
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The Contribution of Carbon and Water in Modulating Wood Formation in Black Spruce Saplings Open
Nonstructural carbohydrates (NSCs) play a crucial role in xylem formation and represent, with water, the main constraint to plant growth. We assessed the relationships between xylogenesis and NSCs in order to (1) verify the variance explai…
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Quantifying Boreal Forest Structure and Composition Using UAV Structure from Motion Open
The vast extent and inaccessibility of boreal forest ecosystems are barriers to routine monitoring of forest structure and composition. In this research, we bridge the scale gap between intensive but sparse plot measurements and extensive …
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Molybdenum and phosphorus limitation of moss‐associated nitrogen fixation in boreal ecosystems Open
Summary Biological nitrogen fixation ( BNF ) performed by moss‐associated cyanobacteria is one of the main sources of new nitrogen (N) input in pristine, high‐latitude ecosystems. Yet, the nutrients that limit BNF remain elusive. Here, we …
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How climate change might affect tree regeneration following fire at northern latitudes: a review Open
Climate change is projected to increase fire severity and frequency in the boreal forest, but it could also directly affect post-fire recruitment processes by impacting seed production, germination, and seedling growth and survival. We rev…
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Deep peat warming increases surface methane and carbon dioxide emissions in a black spruce‐dominated ombrotrophic bog Open
Boreal peatlands contain approximately 500 Pg carbon (C) in the soil, emit globally significant quantities of methane ( CH 4 ), and are highly sensitive to climate change. Warming associated with global climate change is likely to increase…
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Radial Growth Response of Black Spruce Stands Ten Years after Experimental Shelterwoods and Seed-Tree Cuttings in Boreal Forest Open
Partial cutting is thought to be an alternative to achieve sustainable management in boreal forests. However, the effects of intermediate harvest intensity (45%–80%) on growth remain unknown in black spruce (Picea mariana (Mill.) B.S.P.) s…
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Thermokarst rates intensify due to climate change and forest fragmentation in an Alaskan boreal forest lowland Open
Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse‐scar bogs, low shrub/scrub, and forests growing on elevated ice‐rich permafrost soils. Thermokarst has affected the lowlan…
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Assessing the anticipated growth response of northern conifer populations to a warming climate Open
The growth response of trees to ongoing climate change has important implications for future forest dynamics, accurate carbon accounting, and sustainable forest management. We used data from black spruce ( Picea mariana ) and jack pine ( P…
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Daily burned area and carbon emissions from boreal fires in Alaska Open
Boreal fires burn into carbon-rich organic soils, thereby releasing large quantities of trace gases and aerosols that influence atmospheric composition and climate. To better understand the factors regulating boreal fire emissions, we deve…
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Understanding tree growth responses after partial cuttings: A new approach Open
Forest ecosystem management heads towards the use of partial cuttings. However, the wide variation in growth response of residual trees remains unexplained, preventing a suitable prediction of forest productivity. The aim of the study was …
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Topoedaphic and Forest Controls on Post-Fire Vegetation Assemblies Are Modified by Fire History and Burn Severity in the Northwestern Canadian Boreal Forest Open
Wildfires, which constitute the most extensive natural disturbance of the boreal biome, produce a broad range of ecological impacts to vegetation and soils that may influence post-fire vegetation assemblies and seedling recruitment. We inv…
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Factors shaping alternate successional trajectories in burned black spruce forests of Alaska Open
Disturbances can interrupt feedbacks that maintain stable plant community structure and create windows of opportunity for vegetation to shift to alternative states. Boreal forests are dominated by tree species that overlap considerably in …
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Post-cutting Mortality Following Experimental Silvicultural Treatments in Unmanaged Boreal Forest Stands Open
Partial cutting has been recommended as an alternative harvesting method to ensure the sustainable management of boreal forests. The success of this approach is closely linked to the survival of residual trees as additional losses through …
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Conifer Regeneration After Experimental Shelterwood and Seed-Tree Treatments in Boreal Forests: Finding Silvicultural Alternatives Open
Forest regeneration is a key element in achieving sustainable forest management. Partial harvest methods have been used extensively in temperate broadleaf and mixedwood ecosystems to promote regeneration on poorly stocked sites and to main…
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Climatic dipoles drive two principal modes of North American boreal bird irruption Open
Significance This study is the first, to our knowledge, to reveal how climate variability drives irruptions of North American boreal seed-eating birds. Patterns of Pine Siskin irruption and associated climate drivers manifest as two modes …
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Insufficient Chilling Effects Vary among Boreal Tree Species and Chilling Duration Open
Insufficient chilling resulting from rising winter temperatures associated with climate warming has been an area of particular interest in boreal and temperate regions where a period of cool temperatures in fall and winter is required to b…
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Experimental nitrogen addition alters structure and function of a boreal bog: critical load and thresholds revealed Open
Bogs and fens cover 6% and 21%, respectively, of the 140,329 km 2 Oil Sands Administrative Area in northern Alberta. Development of the oil sands has led to increasing atmospheric N deposition, with values as high as 17 kg N·ha −1 ·yr −1 ;…
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Did enhanced afforestation cause high severity peat burn in the Fort McMurray Horse River wildfire? Open
Climate change mediated drying of boreal peatlands is expected to enhance peatland afforestation and wildfire vulnerability. The water table depth–afforestation feedback represents a positive feedback that can enhance peat drying and conso…
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Synchronisms and correlations of spring phenology between apical and lateral meristems in two boreal conifers Open
Phenological synchronisms between apical and lateral meristems could clarify some aspects related to the physiological relationships among the different organs of trees. This study correlated the phenological phases of bud development and …
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The biophysical climate mitigation potential of boreal peatlands during the growing season Open
Peatlands and forests cover large areas of the boreal biome and are critical for global climate regulation. They also regulate regional climate through heat and water vapour exchange with the atmosphere. Understanding how land-atmosphere i…
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Boreal tree hydrodynamics: asynchronous, diverging, yet complementary Open
Water stress has been identified as a key mechanism of the contemporary increase in tree mortality rates in northwestern North America. However, a detailed analysis of boreal tree hydrodynamics and their interspecific differences is still …
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Wood anatomical traits in black spruce reveal latent water constraints on the boreal forest Open
The effects of climate change on high‐latitude forest ecosystems are complex, making forecasts of future scenarios uncertain. The predicted lengthening of the growing season under warming conditions is expected to increase tree growth rate…
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Temporal variation in plant neighborhood effects on the defoliation of primary and secondary hosts by an insect pest Open
Plant neighborhood effects on herbivore damage have been observed in many systems although few studies have assessed the different component effects of the neighborhood (conspecific neighbors vs. heterospecific neighbors) on defoliation. N…
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Patterns of canopy and surface layer consumption in a boreal forest fire from repeat airborne lidar Open
Fire in the boreal region is the dominant agent of forest disturbance with direct impacts on ecosystem structure, carbon cycling, and global climate. Global and biome-scale impacts are mediated by burn severity, measured as loss of forest …
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Experimental assessment of tree canopy and leaf litter controls on the microbiome and nitrogen fixation rates of two boreal mosses Open
Summary Nitrogen (N 2 )‐fixing moss microbial communities play key roles in nitrogen cycling of boreal forests. Forest type and leaf litter inputs regulate moss abundance, but how they control moss microbiomes and N 2 ‐fixation remains und…
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Modified treatment of intercepted snow improves the simulated forest albedo in the Canadian Land Surface Scheme Open
The Canadian Land Surface Scheme (CLASS) was modified to correct an underestimation of the winter albedo in evergreen needleleaf forests. Default values for the visible and near-infrared albedo of a canopy with intercepted snow, αVIS,cs an…
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Adverse climatic periods precede and amplify defoliator‐induced tree mortality in eastern boreal North America Open
As major alterations are occurring in climate and pest ranges, it is imperative to evaluate their combined contribution to tree mortality in order to propose mitigation measures and limit losses in forest productivity. The objective of thi…
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Vulnerability of Conifer Regeneration to Spruce Budworm Outbreaks in the Eastern Canadian Boreal Forest Open
Spruce budworm (Choristoneura fumiferana) is the main defoliator of conifer trees in North American boreal forests, affecting extensive areas and causing marked losses of timber supplies. In 2017, spruce budworm affected more than 7 millio…