Spatiotemporal distribution of light rings in subarctic black spruce, Quebec

1991 ◽  
Vol 21 (12) ◽  
pp. 1828-1832 ◽  
Author(s):  
Ann Delwaide ◽  
Louise Filion ◽  
Serge Payette
Keyword(s):  
Spatial Distribution ◽  
Boreal Forest ◽  
Black Spruce ◽  
Hudson Bay ◽  
Tree Line ◽  
Northern Limit ◽  
The West ◽  
Forest Region ◽  
Boreal Forest Region ◽  
Light Ring

Numerous subfossil trees from the 13th, 14th, and 15th centuries sampled in the Rivière Boniface area (east of Hudson Bay) made it possible to extend to A.D. 1221 a previously published light-ring chronology. The spatial distribution of these diagnostic rings was studied along a south-north and a west–east transect in several sites extending from the northern limit of the Boreal Forest Region to the tree line. Data showed an increase in the number and frequency of light-ring years among populations along the south–north transect but little variations along the west–east transect.

Fungi of the Canadian boreal forest region: Catulus aquilonius gen. et sp.nov., a hyperparasite on Seuratia millardetii

1978 ◽  
Vol 56 (19) ◽  
pp. 2344-2347 ◽  
Author(s):  
D. Malloch ◽  
C. T. Rogerson
Keyword(s):  
Boreal Forest ◽  
New Genus ◽  
New Genus And Species ◽  
Forest Region ◽  
Canadian Boreal Forest ◽  
Boreal Forest Region

A new genus and species of ascomycetes, Catulus aquilonius, is described, illustrated, and tentatively assigned to the Mycosphaerellaceae. It grows as a parasite on stromata of Seuratia millardetii (Raciborski) Meeker and is characterized by two-celled, setulose ascospores.

Kraft Pulping and Specific Gravity in the Uppermost Stem of Fertilized Balsam Fir

1975 ◽  
Vol 5 (3) ◽  
pp. 399-402 ◽  
Author(s):  
J. D. Gagnon ◽  
K. Hunt
Keyword(s):  
Specific Gravity ◽  
Boreal Forest ◽  
Kraft Pulping ◽  
Balsam Fir ◽  
Pulp Yield ◽  
Kraft Process ◽  
Forest Region ◽  
The Mean ◽  
Boreal Forest Region

Samples of five pairs of fertilized and non-fertilized 60-year-old natural balsam fir (Abiesbalsamea (L.) Mill.) growing in the Quebec boreal forest region were pulped by the kraft process and the specific gravity was measured. Analyses carried out 7 years after treatment on the last seven terminal internodes revealed the mean pulp yield of trees fertilized exceeded that of non-fertilized by 7%, while the mean specific gravity was about 6% lower.

Population dynamics of black spruce and white spruce near the arctic tree line in the southern Brooks Range, Alaska

2005 ◽  
Vol 35 (9) ◽  
pp. 2073-2081 ◽  
Author(s):  
Andrea H Lloyd ◽  
Alexis E Wilson ◽  
Christopher L Fastie ◽  
R Matthew Landis
Keyword(s):  
Population Dynamics ◽  
Seed Production ◽  
Matrix Model ◽  
Black Spruce ◽  
White Spruce ◽  
Adult Mortality ◽  
The Arctic ◽  
Tree Line ◽  
Northern Limit ◽  
Fire Intervals

Black spruce (Picea mariana (Mill.) BSP) is the dominant species in interior Alaska but it is largely absent from the arctic tree line. To evaluate the importance of climate and fire as controls over the species distribution, we reconstructed stand history at three sites near its northern limit in Alaska, where it grows with white spruce (Picea glauca (Moench) Voss). We developed a matrix model to explore black spruce population dynamics and response to varying fire intervals. All sites burned in the early 1900s. High recruitment of black spruce occurred for <30 years following the fire, but most current black spruce recruitment is clonal and seed viability is low. White spruce recruitment has been consistently high since the fire, and the majority of seedlings in the stands are white spruce. Despite low recruitment, the matrix model suggests that black spruce populations are nearly stable, largely because of low adult mortality rates. Although black spruce recruitment is stimulated by fire, the model indicates that fire intervals <350 years would destabilize the population, primarily because of slow growth and low seed production. Population dynamics of black spruce at its northern limit in Alaska thus appear to reflect an interaction between fire, which determines the temporal pattern of tree recruitment, and climate, which limits tree growth and, presumably, viable seed production.

scholarly journals Landscape control of uranium and thorium in boreal streams – spatiotemporal variability and the role of wetlands

2012 ◽  
Vol 9 (3) ◽  
pp. 2823-2849 ◽  
Author(s):  
F. Lidman ◽  
C. M. Mörth ◽  
H. Laudon
Keyword(s):  
Boreal Forest ◽  
Gamma Spectrometry ◽  
Spatiotemporal Variability ◽  
Forest Landscape ◽  
Spatiotemporal Variations ◽  
Forest Region ◽  
Boreal Streams ◽  
Landscape Control ◽  
Boreal Forest Region

Abstract. The concentrations of uranium and thorium in ten partly nested streams in the boreal forest region were monitored over a two-year period. Considerable spatiotemporal variations were observed, with little or no correlation between streams. The export of both uranium and thorium varied substantially between the subcatchments, ranging from 1.7 to 30 g km−2 a−1 for uranium and from 3.2 to 24 g km−2 a−1 for thorium. Airborne gamma spectrometry was used to measure the concentrations of uranium and thorium in surface soils throughout the catchment, but could not explain the variability in the export. Instead, the extent of lakes and mires within each subcatchment was found to be a stronger predictor for the transport of uranium and thorium. The results indicate that there is a predictable and systematic accumulation of both uranium and thorium in boreal mires. Approximately 65–80 % of uranium and 55–65 % of thorium entering a mire is estimated to be retained in the peat. Overall, accumulation in mires and other types of wetlands is estimated to decrease the fluxes of uranium and thorium from the boreal forest landscape by 30–40 %. The atmospheric deposition of uranium and thorium was also quantified and its contribution to boreal streams was found to be low compared to weathering.

Satellite Based Engineering-Terrain Mapping of Canada's Boreal Forest Region

2000 ◽  
Author(s):  
V Singhroy ◽  
P Barnett ◽  
S M Yatabe ◽  
R Saint-Jean
Keyword(s):  
Boreal Forest ◽  
Terrain Mapping ◽  
Forest Region ◽  
Boreal Forest Region
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