The occurrence of bisexual strobiles on black spruce (Piceamariana (Mill.) B.S.P.) in the forest-tundra ecotone: Keewatin, Northwest Territories

1979 ◽  
Vol 9 (4) ◽  
pp. 545-545
Author(s):  
Deborah L. Elliott
Keyword(s):  
Northwest Territories ◽  
Black Spruce ◽  
Forest Tundra

not available

The occurrence of bisexual strobiles on black spruce (Piceamariana (Mill.) B.S.P.) in the forest–tundra ecotone: Keewatin, Northwest Territories

1979 ◽  
Vol 9 (2) ◽  
pp. 284-286 ◽  
Author(s):  
Deborah L. Elliott
Keyword(s):  
Northwest Territories ◽  
Black Spruce ◽  
Reproductive Tissue ◽  
Reproductive Structure ◽  
Lake District ◽  
Male And Female ◽  
Forest Tundra ◽  
Marginal Environment

During fieldwork in the summer of 1977 in the vicinity of Ennadai Lake (District of Keewatin, N.W.T., Canada), a stand of upland black spruce (Piceamariana (Mill.) B.S.P.) possessing bisexual strobiles was encountered within the forest–tundra ecotone. This is the first reported occurrence of bisexual strobiles for this species. It is hypothesized that the occurrence of male and female reproductive tissue in the same reproductive structure is an indicator of stress in this arboreally marginal environment.

Soil organic layer combustion in boreal black spruce and jack pine stands of the Northwest Territories, Canada

2018 ◽  
Vol 27 (2) ◽  
pp. 125 ◽  
Author(s):  
Xanthe J. Walker ◽  
Jennifer L. Baltzer ◽  
Steven G. Cumming ◽  
Nicola J. Day ◽  
Jill F. Johnstone ◽  
...  
Keyword(s):  
Northwest Territories ◽  
Boreal Forests ◽  
Black Spruce ◽  
Jack Pine ◽  
Fire Intensity ◽  
Organic Layer ◽  
Complete Combustion ◽  
Soil Organic Layer ◽  
Pine Stands ◽  
Burn Depth

Increased fire frequency, extent and severity are expected to strongly affect the structure and function of boreal forest ecosystems. In this study, we examined 213 plots in boreal forests dominated by black spruce (Picea mariana) or jack pine (Pinus banksiana) of the Northwest Territories, Canada, after an unprecedentedly large area burned in 2014. Large fire size is associated with high fire intensity and severity, which would manifest as areas with deep burning of the soil organic layer (SOL). Our primary objectives were to estimate burn depth in these fires and then to characterise landscapes vulnerable to deep burning throughout this region. Here we quantify burn depth in black spruce stands using the position of adventitious roots within the soil column, and in jack pine stands using measurements of burned and unburned SOL depths. Using these estimates, we then evaluate how burn depth and the proportion of SOL combusted varies among forest type, ecozone, plot-level moisture and stand density. Our results suggest that most of the SOL was combusted in jack pine stands regardless of plot moisture class, but that black spruce forests experience complete combustion of the SOL only in dry and moderately well-drained landscape positions. The models and calibrations we present in this study should allow future research to more accurately estimate burn depth in Canadian boreal forests.

Modern pollen assemblages near the arctic tree line, Mackenzie Delta region, Northwest Territories

1974 ◽  
Vol 52 (2) ◽  
pp. 381-396 ◽  
Author(s):  
J. C. Ritchie
Keyword(s):  
Northwest Territories ◽  
Lake Sediment ◽  
Local Community ◽  
The Arctic ◽  
Forest Site ◽  
Mackenzie Delta ◽  
Forest Tundra ◽  
Transitional Area ◽  
Modern Pollen ◽  
Pollen Rain

Samples of surficial lake sediment and of moss polsters from 39 sites in the forest-tundra transitional area immediately east of the Mackenzie Delta, Northwest Territories, were investigated palynologically. Lake sediment samples within the forest and tundra regional vegetation zones are constant in pollen frequencies, but forest–tundra sites are very variable. Forest site spectra are composed of just over 50% arboreal types (spruce, 25–30%; birch, 30%), with 30–40% alder pollen. Tundra spectra have 60–70% non-arboreal types, and 10–15% each of alder and spruce. Forest–tundra values are variable, generally lying between the forest and tundra proportions. Polster samples show as much variability within as between regions, because of local effects. Polster samples indicate local community composition with the regional pollen rain variably masked by the local elements.

scholarly journals Hydrometeorological data from Baker Creek Research Watershed, Northwest Territories, Canada

2018 ◽  
Vol 10 (4) ◽  
pp. 1753-1767 ◽  
Author(s):  
Christopher Spence ◽  
Newell Hedstrom
Keyword(s):  
Northwest Territories ◽  
Black Spruce ◽  
Barometric Pressure ◽  
Turbulent Energy ◽  
Daily Streamflow ◽  
Radiation Fluxes ◽  
Geophysical Processes ◽  
Streamflow Data ◽  
Environmental Prediction

Abstract. It is uncommon to collect long-term coordinated hydrometeorological and hydrological data in northern circumpolar regions. However, such datasets can be very valuable for engineering design, improving environmental prediction tools or detecting change. This dataset documents physiographic, hydrometeorological and hydrological conditions in the Baker Creek Research Watershed from 2003 to 2016. Baker Creek drains water from 155 km2 of subarctic Canadian Shield terrain in Canada's Northwest Territories. half-hourly hydrometeorological data were collected each year, at least from April to October, from representative locations, including exposed Precambrian bedrock ridges, peatlands, open black spruce forest and lakes. Hydrometeorological data include radiation fluxes, rainfall, temperature, humidity, winds, barometric pressure and turbulent energy fluxes. Terrestrial sites were monitored for ground temperature and soil moisture. Spring maximum snowpack water equivalent, depth and density data are included. Daily streamflow data are available for a series of nested watersheds ranging in size from 9 to 128 km2. These data are unique in this remote region and provide scientific and engineering communities with an opportunity to advance understanding of geophysical processes and improve infrastructure resiliency. The data described here are available at: https://doi.org/10.20383/101.026.

scholarly journals Impacts of Climatic Variation on the Growth of Black Spruce Across the Forest-Tundra Ecotone: Positive Effects of Warm Growing Seasons and Heat Waves Are Offset by Late Spring Frosts

2020 ◽  
Vol 3 ◽  
Author(s):  
Guillaume Moreau ◽  
Catherine Chagnon ◽  
David Auty ◽  
John Caspersen ◽  
Alexis Achim
Keyword(s):  
Climate Change ◽  
North America ◽  
Black Spruce ◽  
Growing Season ◽  
Late Spring ◽  
Climatic Data ◽  
Northeastern North America ◽  
Forest Tundra ◽  
Growing Seasons ◽  
Spring Frosts

Climate strongly limits the physiological processes of trees near their range limits, leading to increased growth sensitivity. Northeastern North America is experiencing considerable warming, so the growth of trees near the northern treeline represents a key indicator of forest responses to climate change. However, tree-ring series and corresponding climatic data are scarce across the forest-tundra ecotone when compared to southern boreal regions, resulting in fewer studies on growth-climate relationships focused on this ecotone. Using daily climatic data, we identified trends in growing season heat accumulation and the intensity of acute climatic events over the last several decades in the southern and the northern parts of the forest-tundra ecotone in northeastern North America, and investigated their influence on black spruce radial growth. We found that black spruce trees responded positively to the increase in growing season temperatures and heat wave intensity, suggesting that growth is currently limited by suboptimal temperatures. While tree growth in the southern region generally benefited from warm spring temperatures, vulnerability to late spring frosts reduced tree growth in the northern region and increased probability of abrupt growth decline. In this region, late spring frosts offset approximately half of the additional growth that would otherwise occur over the course of a warm growing season. This vulnerability of northern trees may result from local adaptations to short growing seasons, which initiate biological activities at colder temperatures in the spring. Overall, our results highlight the need to explicitly incorporate acute climatic events into modeling efforts in order to refine our understanding of the impact of climate change on forest dynamics.

Feathermoss seedbeds facilitate black spruce seedling recruitment in the forest-tundra ecotone (Labrador, Canada)

Oikos ◽  
2011 ◽  
Vol 120 (8) ◽  
pp. 1263-1271 ◽  
Author(s):  
Julia A. Wheeler ◽  
Luise Hermanutz ◽  
Paul M. Marino
Keyword(s):  
Seedling Recruitment ◽  
Black Spruce ◽  
Forest Tundra

scholarly journals Hydrometeorological Data from Baker Creek Research Watershed, Northwest Territories, Canada

2018 ◽  
Author(s):  
Christopher Spence ◽  
Newell Hedstrom
Keyword(s):  
Northwest Territories ◽  
Black Spruce ◽  
Barometric Pressure ◽  
Turbulent Energy ◽  
Daily Streamflow ◽  
Radiation Fluxes ◽  
Geophysical Processes ◽  
Streamflow Data ◽  
Environmental Prediction

Abstract. It is uncommon to collect long term coordinated hydrometeorological and hydrological data in northern circumpolar regions. However, such datasets can be very valuable for engineering design, improving environmental prediction tools or detecting change. This dataset documents physiographic, hydrometeorological and hydrological conditions in the Baker Creek Research Watershed from 2003 to 2016. Baker Creek drains water from 155 km2 of subarctic Canadian Shield terrain in Canada's Northwest Territories. Seasonal half hourly hydrometeorological data were collected from representative locations, including exposed Precambrian bedrock ridges, peatlands, open black spruce forest and lakes. Hydrometeorological data includes radiation fluxes, rainfall, temperature, humidity, winds, barometric pressure, and turbulent energy fluxes. Terrestrial sites were monitored for ground temperature and soil moisture. Spring maximum snowpack water equivalent, depth and density data are included. Daily streamflow data are available from a series of nested watersheds ranging from in size from 9 to 128 km2. These data are unique in this remote region and provide scientific and engineering communities with an opportunity to advance understanding of geophysical processes and improve infrastructure resiliency. The data described here are available at: https://www.frdr.ca/repo/handle/doi:10.20383/101.026

scholarly journals “These Trees Have Stories to Tell”: Linking Dënesǫ́łıné Oral History of Caribou Use with Trample Scar Frequency on Black Spruce Roots at Ɂedacho Kué

ARCTIC ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 290-305
Author(s):  
Kelsey L. Dokis-Jansen ◽  
Brenda L. Parlee ◽  
Łutsël K’e Dëne First Nation ◽  
David S. Hik ◽  
Benoit Gendreau-Berthiaume ◽  
...  
Keyword(s):  
Oral History ◽  
Northwest Territories ◽  
Collaborative Research ◽  
Rangifer Tarandus ◽  
Black Spruce ◽  
Scientific Data ◽  
Oral Histories ◽  
Research Approach ◽  
Barren Ground ◽  
History Of

For thousands of years Ɂedacho Kué (Artillery Lake, Northwest Territories) has been a key water crossing site for barren-ground caribou (Rangifer tarandus groenlandicus). Human disturbance of barren-ground caribou habitat in northern Canada has emerged as an important focus of study in the last decade; particularly in the Bathurst range of the Northwest Territories where caribou populations have declined by more than 95% since the 1980s. Guided by local Indigenous leaders and Elders, a collaborative research project was developed with the Dënesǫ́łıné people of Łutsël K’e Dëne First Nation (2012 – 14). This paper describes linkages between knowledge derived from Dënesǫ́łıné oral history and quantitative dendroecological analysis of trample scars on black spruce (Picea mariana) root samples collected at Ɂedacho Kué to provide a better understanding of caribou use at this location. Findings from oral histories and dendroecology analysis were consistent with one another and with previous dendroecology study in the region, although some discrepancies were detected in data from 1995 – 2006 that require further study to elucidate. Key findings include relatively low caribou use at Ɂedacho Kué during the 1930s and late 1960s, with use increasing into the 1970s and peaking in the late 1980s, as well as Elder and hunter reports of no caribou in some years between 2005 and 2012. This work addresses a gap in scientific data about barren-ground caribou movements at Ɂedacho Kué prior to satellite collar use in 1996 and corroborates previously documented oral histories about the enduring value of Ɂedacho Kué as critical habitat to barren-ground caribou. Given the drastic decline of the Bathurst caribou over the last two decades, more research is needed to understand movements and their relationship to population dynamics. In this context, the research approach described in this paper could be used as an example of how to meaningfully bring together place-based Indigenous knowledge and science in addressing an urgent issue of Arctic sustainability. 

Zonation des conditions d'enneigement en toundra forestière, Baie d'Hudson, Nouveau-Québec

1975 ◽  
Vol 53 (10) ◽  
pp. 1021-1030 ◽  
Author(s):  
Serge Payette ◽  
Jacques Ouzilleau ◽  
Louise Filion
Keyword(s):  
Picea Glauca ◽  
Snow Depth ◽  
Black Spruce ◽  
Ground Cover ◽  
Climatic Conditions ◽  
Snow Density ◽  
Forest Tundra ◽  
Snow Properties ◽  
Latitudinal Pattern ◽  
Snow Conditions

Data on snow depth and snow density of various forest–tundra coniferous stands are presented in this paper. A latitudinal pattern in snow conditions is observed in the forest–tundra environment, as predicted from the facts that are obtained when this phytogeographical region is subdivided, firstly, into a forested subzone in the southern part and a shrub subzone (or krummholz) in the northern part and, secondly, into a maritime ecoclimatic area near Hudson Bay and a continental ecoclimatic area inland. The most snowy coniferous stands are located in the shrub subzone; snow density rises gradually from the taiga to the tundra. The highest values in snow properties are found in the maritime ecoclimatic area. These data suggest the following observations: (1) maximum snow depth measured in the northern part of the forest–tundra is explained by an increase of barren ground cover and by the presence of more open coniferous stands, which favor snow drifting and snow trapping; (2) the gradual increase in snow density is related to more rigorous climatic conditions; wind exposure is rather important since these sites are getting more open; and (3) the differences in snow conditions between the ecoclimatic areas show that the maritime environment is more windy; the presence of scattered and erected white spruce (Picea glauca (Moench) Voss) in various krummholz formations in that area favors more efficient snow traps than those of krummholz formations located in the continental area. The latter is dominated by prostrate and erect black spruce (Picea mariana (Mill.) BSP.) always densely agglomerated. The latitudinal pattern in snow conditions reflects the climatic conditions of the forest–tundra, and this determines the specific ecological distribution of coniferous stands.

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