scholarly journals Regeneration Dynamics of White Spruce, Trembling Aspen, and Balsam Poplar in Response to Disturbance, Climatic, and Edaphic Factors in the Cold, Dry Boreal Forests of the Southwest Yukon, Canada

2015 ◽  
Vol 113 (5) ◽  
pp. 463-474 ◽  
Author(s):  
Shyam K. Paudel ◽  
Craig R. Nitschke ◽  
Suzanne W. Simard ◽  
John L. Innes
Keyword(s):  
Boreal Forests ◽  
White Spruce ◽  
Edaphic Factors ◽  
Trembling Aspen ◽  
Regeneration Dynamics ◽  
Balsam Poplar

scholarly journals Modelling Growth-Competition Relationships in Trembling Aspen and White Spruce Mixed Boreal Forests of Western Canada

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e77607 ◽  
Author(s):  
Jian-Guo Huang ◽  
Kenneth J. Stadt ◽  
Andria Dawson ◽  
Philip G. Comeau
Keyword(s):  
Boreal Forests ◽  
White Spruce ◽  
Western Canada ◽  
Trembling Aspen

scholarly journals A Comparison of Existing Models for DBH Estimation from Large-scale Photos

1989 ◽  
Vol 65 (2) ◽  
pp. 114-120 ◽  
Author(s):  
R. J. Hall ◽  
R. T. Morton ◽  
R. N. Nesby
Keyword(s):  
Large Scale ◽  
Prediction Models ◽  
Lodgepole Pine ◽  
Tree Height ◽  
White Spruce ◽  
Trembling Aspen ◽  
Crown Area ◽  
Balsam Poplar ◽  
Operational Test ◽  
Highly Correlated

The performance of 12 diameter prediction models suggested in the literature was studied in a controlled operational test. These models were linear and logarithmic transformations of tree height and/or crown area and were analyzed for white spruce, lodgepole pine, and trembling aspen and balsam poplar combined. Overall, all models were statistically significant, with differences due to variations in species and model form. Although simpler models may be adequate depending on operational objectives, two models emerged as deserving further investigation. It was unclear whether both tree height and crown area were needed as predictors of tree dbh for all species. Tree height was more highly correlated with dbh than crown area for all species except lodgepole pine. Measuring both tree height and crown area in comparison with tree height alone, however, increases measurement cost substantially from $10.29 to $17.50 per plot (1987 dollars).

The interactive effect of competition and climate on growth of boreal tree species in western Canada and Alaska

2020 ◽  
Vol 50 (5) ◽  
pp. 457-464 ◽  
Author(s):  
Felix O. Oboite ◽  
Philip G. Comeau
Keyword(s):  
Interspecific Competition ◽  
Tree Growth ◽  
Intraspecific Competition ◽  
Tree Species ◽  
Basal Area ◽  
White Spruce ◽  
Jack Pine ◽  
Western Canada ◽  
Trembling Aspen ◽  
Balsam Poplar

Understanding interactions between competition and climate in relation to their effects on individual tree growth is crucial to the development of climate-sensitive growth models required for modelling boreal forest succession in a changing climate. We used data from permanent growth and yield sample plots in western Canada and Alaska to investigate the impact of competition within a regional gradient of climatic conditions for lodgepole pine (Pinus contorta Douglas ex Loudon), jack pine (Pinus banksiana Lamb.), trembling aspen (Populus tremuloides Michx.), balsam poplar (Populus balsamifera L.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.). We characterized the effects of competition (basal area of spruce–fir, deciduous, and pine trees larger than the focal tree) and climate (mean annual temperature and precipitation) and their interactions on basal area growth of individual trees using linear mixed-effects models. Our results indicated that intraspecific competition had stronger effects on growth than interspecific competition and climate. Moreover, significant interactions between intraspecific competition and climate suggest that an increase in intraspecific competition will lead to a reduction in tree growth for warmer regions (lodgepole pine, trembling aspen, balsam poplar, and white spruce) and wetter regions (jack pine). The manner in which interspecific competition altered tree growth responses to climate was variable, depending on tree species and competition type. These results indicate that the relationships between growth and climate may differ according to the degree of competition and the structure of the stand.

scholarly journals Splitting in Fire-Killed Trees in the Boreal Forest of Alberta

2003 ◽  
Vol 20 (4) ◽  
pp. 167-174
Author(s):  
Nobutaka Nakamura ◽  
Paul M. Woodard ◽  
Lars Bach
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Black Spruce ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Balsam Fir ◽  
Crown Fire ◽  
In Fire ◽  
Solar Angle

Abstract Tree boles in the boreal forests of Alberta, Canada will split once killed by a stand-replacing crown fire. A total of 1,485 fire-killed trees were sampled, 1 yr after burning, in 23 plots in 14 widely separated stands within a 370,000 ha fire. Sampling occurred in the Upper and Lower Foothills natural subregions. The frequency of splitting varied by species but averaged 41% for all species. The order in the frequency of splitting was balsam fir, black spruce, white spruce and lodgepole pine. The type of splitting (straight, spiral, or multiple) varied by species, as did the position of the split on the tree bole. Aspect or solar angle was not statistically related to the type or occurrence of splitting.

scholarly journals THE STORY OF A CUT-OVER

1954 ◽  
Vol 30 (2) ◽  
pp. 158-182
Author(s):  
I. Kagis
Keyword(s):  
White Spruce ◽  
Decisive Factor ◽  
Cyclic Process ◽  
Third Wave ◽  
Trembling Aspen ◽  
Mixed Stands ◽  
Considerable Part ◽  
The Third

1. A considerable part of the mixed white spruce—trembling aspen stands in Saskatchewan appears to be forming itself in a cyclic process. After a fire, when poplar has established itself, the first wave of spruce comes in; the second follows in about 50 to 70 years. When the trembling aspen thins itself, the crest of the third wave comes and, together with the remaining apsen, the spruce of the first wave starts to deteriorate.2. This cyclic development of such stands seems to provide an opportunity to apply management on the basis of a permanent forest.3. Cutting by diameter limit in such stands results in windthrow and die-off, exceeding the increment of the residual white spruce.4. Crown quality is a decisive factor with white spruce in its response to release in these mixed stands.5. White spruce in these mixed stands responds to release even at the age of 100 years.6. Insufficient regeneration of white spruce in the examined area appears to be due to lack of seed; heavy sod, invasion of shrubs and weeds seem to be main obstacles to regeneration.

scholarly journals Taper Equations for Five Major Commercial Tree Species in Manitoba, Canada

2007 ◽  
Vol 22 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Ryan J. Klos ◽  
G. Geoff Wang ◽  
Qing-Lai Dang ◽  
Ed W. East
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
White Spruce ◽  
Jack Pine ◽  
Volume Estimation ◽  
Trembling Aspen ◽  
Stem Form ◽  
Taper Equation ◽  
Taper Equations

Abstract Kozak's variable exponent taper equation was fitted for balsam poplar (Populus balsamifera L.), trembling aspen (Populus tremuloides Michx.), white spruce (Picea glauca [Moench] Voss), black spruce (Picea mariana [Mill.] B.S.P.), and jack pine (Pinus banksiana Lamb.) in Manitoba. Stem taper variability between two ecozones (i.e., Boreal Shield and Boreal Plains) were tested using the F-test. Regional differences were observed for trembling aspen, white spruce, and jack pine, and for those species, separate ecozone-specific taper equations were developed. However, the gross total volume estimates using the ecozone-specific equations were different from those of the provincial equations by only 2 percent. Although the regional difference in stem form was marginal within a province, a difference of approximately 7 percent of gross total volume estimation was found when our provincial taper equations were compared with those developed in Alberta and Saskatchewan. These results suggest that stem form variation increases with spatial scale and that a single taper equation for each species may be sufficient for each province.

Some climatic aspects of biomass productivity of white spruce stem wood

1987 ◽  
Vol 17 (9) ◽  
pp. 1075-1079 ◽  
Author(s):  
L. A. Jozsa ◽  
J. M. Powell
Keyword(s):  
Boreal Forests ◽  
Biomass Productivity ◽  
White Spruce ◽  
Ice Age ◽  
Stem Wood ◽  
Breast Height ◽  
Sampling Locations ◽  
Tree Ring Data ◽  
Canadian Boreal Forest ◽  
Old Trees

Biomass productivity was determined for white spruce (Piceaglauca (Moench) Voss) in the boreal forests of Alberta, the Northwest Territories, and Manitoba. Comparisons were made between southern and northern locations, between eastern and western transect locations, and between older (200 + years) and younger (110 years) trees. At 13 sampling locations, X-ray densitometric tree ring data were obtained from the base of the stem, breast height, and from five points equidistant along the stem. Markedly higher stem wood biomass productivity was found for the 110-year-old trees than for the 210-year-old trees in Alberta; average ring weights were 3.8 and 1.2 g for the first 100 years of growth in 1 cm thick disks at breast height. These results suggest that climatic warming since the end of the Little Ice Age (ca. 1850) has resulted in higher biomass productivity in the Canadian boreal forest.

Within-crown distribution patterns of white spruce in pure composition and in mixture with trembling aspen

Ecoscience ◽  
2014 ◽  
Vol 21 (3-4) ◽  
pp. 187-201 ◽  
Author(s):  
Sandra R. Carr ◽  
Nancy Luckai ◽  
Guy R. Larocque ◽  
Douglas E. B. Reid
Keyword(s):  
White Spruce ◽  
Distribution Patterns ◽  
Trembling Aspen

Within-tree patterns of wood stiffness for white spruce (Picea glauca) and trembling aspen (Populus tremuloides)

2014 ◽  
Vol 44 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Derek F. Sattler ◽  
Philip G. Comeau ◽  
Alexis Achim
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Radial Growth ◽  
Tree Height ◽  
White Spruce ◽  
Vertical Position ◽  
Trembling Aspen ◽  
Mixed Effect ◽  
Cambial Age ◽  
Rate Of Increase

Radial patterns of modulus of elasticity (MOE) were examined for white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuoides Michx.) from 19 mature, uneven-aged stands in the boreal mixedwood region of northern Alberta, Canada. The main objectives were to (1) evaluate the relationship between pith-to-bark changes in MOE and cambial age or distance from pith; (2) develop species-specific models to predict pith-to-bark changes in MOE; and (3) to test the influences of radial growth, relative vertical height, and tree slenderness (tree height/DBH) on MOE. For both species, cambial age was selected as the best explanatory variable with which to build pith-to-bark models of MOE. For white spruce and trembling aspen, the final nonlinear mixed-effect models indicated that an augmented rate of increase in MOE occurred with increasing vertical position within the tree. For white spruce trees, radial growth and slenderness were found to positively influence maximum estimated MOE. For trembling aspen, there was no apparent effect of vertical position or radial growth on maximum MOE. The results shed light on potential drivers of radial patterns of MOE and will be useful in guiding silvicultural prescriptions.

Carbon balance of the taiga forest within Alaska: present and future

2002 ◽  
Vol 32 (5) ◽  
pp. 757-767 ◽  
Author(s):  
John Yarie ◽  
Sharon Billings
Keyword(s):  
Boreal Forest ◽  
Black Spruce ◽  
White Spruce ◽  
Carbon Dynamics ◽  
Mean Annual Temperature ◽  
Century Model ◽  
Inventory Data ◽  
Balsam Poplar ◽  
Taiga Forest ◽  
Paper Birch

Forest biomass, rates of production, and carbon dynamics are a function of climate, plant species present, and the structure of the soil organic and mineral layers. Inventory data from the U.S. Forest Service (USFS) Inventory Analysis Unit was used to develop estimates of the land area represented by the major overstory species at various age-classes. The CENTURY model was then used to develop an estimate of carbon dynamics throughout the age sequence of forest development for the major ecosystem types. The estimated boreal forest area in Alaska, based on USFS inventory data is 17 244 098 ha. The total aboveground biomass within the Alaska boreal forest was estimated to be 815 330 000 Mg. The CENTURY model estimated maximum net ecosystem production (NEP) at 137, 88, 152, 99, and 65 g·m–2·year–1 for quaking aspen (Populus tremuloides Michx.), paper birch (Betula papyrifera Marsh.), balsam poplar (Populus balsamifera L.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) BSP) forest stands, respectively. These values were predicted at stand ages of 80, 60, 41, 68, and 100 years, respectively. The minimum values of NEP for aspen, paper birch, balsam poplar, white spruce, and black spruce were –171, –166, –240, –300, and –61 g·m–2·year–1 at the ages of 1, 1, 1, 1, and 12, respectively. NEP became positive at the ages of 14, 19, 16, 13, and 34 for aspen, birch, balsam poplar, white spruce, and black spruce ecosystems, respectively. A 5°C increase in mean annual temperature resulted in a higher amount of predicted production and decomposition in all ecosystems, resulting in an increase of NEP. We estimate that the current vegetation absorbs approximately 9.65 Tg of carbon per year within the boreal forest of the state. If there is a 5°C increase in the mean annual temperature with no change in precipitation we estimated that NEP for the boreal forest in Alaska would increase to 16.95 Tg of carbon per year.

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