scholarly journals Primary and Secondary Branch Growth in Black Spruce and Balsam Fir after Careful Logging around Small Merchantable Stems (CLASS)

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 500 ◽  
Author(s):  
Audrey Lemay ◽  
Cornelia Krause ◽  
Alexis Achim
Keyword(s):  
Boreal Forest ◽  
Radial Growth ◽  
Black Spruce ◽  
Secondary Growth ◽  
Balsam Fir ◽  
Secondary Branch ◽  
Partial Cutting ◽  
Branch Diameter ◽  
Branch Growth ◽  
Post Class

Careful logging around small merchantable stems (CLASS) is a partial cutting treatment that consists of the harvest of 70%–90% of the merchantable volume of an irregular coniferous stand. In this treatment, regeneration, saplings and small merchantable stems (DBH < 15 cm) are preserved and can continue to grow and develop into the dominant layer of the new stand. The aim of this project was to examine the effects of CLASS on the primary and secondary growth of branches, as well as on branch diameter in black spruce and balsam fir trees in the boreal forest of Quebec, Canada. Primary and secondary growth were measured on five branches per tree while branch diameter was analysed from 15 whorls distributed within the crown of the 48 black spruce and 48 balsam fir trees sampled. Branch primary and secondary growth significantly increased after CLASS in the lower part of the crown in both species, and both types of growth increased proportionally. These findings suggest that CLASS may delay crown recession as the lower branches tend to survive and grow for a longer period. However, although radial growth increased in the years post-CLASS, this did not significantly influence the final branch diameter and should not lead to lumber downgrade.

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 Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec

2011 ◽  
Vol 87 (05) ◽  
pp. 669-683 ◽  
Author(s):  
Martin Riopel ◽  
Jean Bégin ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Annual Rainfall ◽  
Deciduous Species ◽  
Partial Cutting ◽  
Coniferous Species ◽  
Breast Height ◽  
Silvicultural Treatments ◽  
Heavy Equipment

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.

Residual-tree growth responses to partial stand harvest in the black spruce (Picea mariana) boreal forestThis article is one of a selection of papers published in the Special Forum IUFRO 1.05 Uneven-Aged Silvicultural Research Group Conference on Natural Disturbance-Based Silviculture: Managing for Complexity.

2007 ◽  
Vol 37 (9) ◽  
pp. 1563-1571 ◽  
Author(s):  
H. C. Thorpe ◽  
S. C. Thomas ◽  
J. P. Caspersen
Keyword(s):  
Boreal Forest ◽  
Tree Growth ◽  
Picea Mariana ◽  
Radial Growth ◽  
Growth Response ◽  
Black Spruce ◽  
Tree Age ◽  
Growth Responses ◽  
Partial Harvest ◽  
Partial Harvesting

Variants of partial harvesting are gaining favour as means to balance ecosystem management and timber production objectives on managed boreal forest landscapes. Understanding how residual trees respond to these alternative silvicultural treatments is a critical step towards evaluating their potential from either a conservation or a wood supply perspective. We used dendroecological techniques combined with a chronosequence approach to quantify the temporal radial growth response pattern of residual black spruce ( Picea mariana (Mill.) BSP) trees to partial harvest in northeastern Ontario. At its peak, 8–9 years after harvest, radial growth of residual trees had doubled. The growth pattern was characterized by a 2-year phase of no response, a subsequent period of increase 3–9 years after harvest, and a stage of declining rates 10–12 years after harvest. The magnitude of tree growth response depended strongly on tree age: peak postharvest growth was substantially higher for young trees, while old trees displayed only modest growth increases. Both the large magnitude and the time delay in postharvest growth responses have important implications for the development of more accurate quantitative tools to project future yields and, more generally, for determining whether partial harvesting is a viable management option for the boreal forest.

scholarly journals Models of knot and stem development in black spruce trees indicate a shift in allocation priority to branches when growth is limited

2014 ◽  
Author(s):  
Emmanuel Duchateau ◽  
David Auty ◽  
Frédéric Mothe ◽  
Fleur Longuetaud ◽  
Chhun Huor Ung ◽  
...  
Keyword(s):  
Radial Growth ◽  
Forest Canopy ◽  
Black Spruce ◽  
Secondary Growth ◽  
Tree Age ◽  
Growth Unit ◽  
Radial Increment ◽  
Initial Growth ◽  
Branch Autonomy ◽  
Computed Tomography Images

The branch autonomy principle, which states that the growth of individual branches can be predicted from their morphology and position in the forest canopy irrespective of the characteristics of the tree, has been used to simplify models of branch growth in trees. However, observed changes in allocation priority within trees towards branches growing in light-favoured conditions, referred to as ‘Milton’s Law of resource availability and allocation’, have raised questions about the applicability of the branch autonomy principle. We present models linking knot ontogeny to the secondary growth of the main stem in black spruce (Picea mariana (Mill.) B.S.P.), which were used to assess the patterns of assimilate allocation over time, both within and between trees. Data describing the annual radial growth of 445 stem rings and the three-dimensional shape of 5377 knots were extracted from optical scans and X-ray computed tomography images taken along the stems of 10 trees. Total knot to stem area increment ratios (KSR) were calculated for each year of growth, and statistical models were developed to describe the annual development of knot diameter and curvature as a function of stem radial increment, total tree height, stem diameter, and the position of knots along an annual growth unit. KSR varied as a function of tree age and of the height to diameter ratio of the stem, a variable indicative of the competitive status of the tree. Simulations of the development of an individual knot showed that an increase in the stem radial growth rate was associated with an increase in the initial growth of the knot, but also with a shorter lifespan. Our results provide support for ‘Milton’s Law’, since they indicate that allocation priority is given to locations where the potential return is the highest. The developed models provided realistic simulations of knot morphology within trees, which could be integrated into a functional-structural model of tree growth and above-ground resource partitioning.

Hierarchical analysis of black spruce and balsam fir wood density in Newfoundland

2015 ◽  
Vol 45 (7) ◽  
pp. 805-816 ◽  
Author(s):  
Arthur Groot ◽  
Joan E. Luther
Keyword(s):  
Wood Density ◽  
Fixed Effects ◽  
Radial Growth ◽  
Black Spruce ◽  
Balsam Fir ◽  
Hierarchical Analysis ◽  
Practical Application ◽  
Structural Hierarchy ◽  
Multiple Levels ◽  
Different Levels

We used a hierarchical approach to examine patterns of black spruce and balsam fir wood density across Newfoundland. Wood density measurements were aggregated at ring, tree, and plot levels. Portions of the variance in wood density at the different levels were explained by predictor variables at multiple levels of a forest structural hierarchy (ring-, tree-, and plot-level variables). Hierarchical fixed effects models accounted for 39%, 61%, and 86% of the variance in wood density of black spruce at ring, tree, and plot levels, respectively, with RMSE values of 62.7, 34.6, and 19.4 kg·m−3. Corresponding models accounted for 31%, 38%, and 63% of the variance in wood density of balsam fir, with RMSE values of 62.4, 35, and 16.7 kg·m−3. The hierarchical analysis demonstrated consistent negative associations of wood density to radial growth rate at ring, tree, and plot levels of aggregation. Variables that act as surrogates for radial growth are thus important for understanding patterns of wood density at higher scales and for the practical application of mapping wood density across landscapes.

scholarly journals Models of knot and stem development in black spruce trees indicate a shift in allocation priority to branches when growth is limited

2014 ◽  
Author(s):  
Emmanuel Duchateau ◽  
David Auty ◽  
Frédéric Mothe ◽  
Fleur Longuetaud ◽  
Chhun Huor Ung ◽  
...  
Keyword(s):  
Radial Growth ◽  
Forest Canopy ◽  
Black Spruce ◽  
Secondary Growth ◽  
Tree Age ◽  
Growth Unit ◽  
Radial Increment ◽  
Initial Growth ◽  
Branch Autonomy ◽  
Computed Tomography Images

The branch autonomy principle, which states that the growth of individual branches can be predicted from their morphology and position in the forest canopy irrespective of the characteristics of the tree, has been used to simplify models of branch growth in trees. However, observed changes in allocation priority within trees towards branches growing in light-favoured conditions, referred to as ‘Milton’s Law of resource availability and allocation’, have raised questions about the applicability of the branch autonomy principle. We present models linking knot ontogeny to the secondary growth of the main stem in black spruce (Picea mariana (Mill.) B.S.P.), which were used to assess the patterns of assimilate allocation over time, both within and between trees. Data describing the annual radial growth of 445 stem rings and the three-dimensional shape of 5377 knots were extracted from optical scans and X-ray computed tomography images taken along the stems of 10 trees. Total knot to stem area increment ratios (KSR) were calculated for each year of growth, and statistical models were developed to describe the annual development of knot diameter and curvature as a function of stem radial increment, total tree height, stem diameter, and the position of knots along an annual growth unit. KSR varied as a function of tree age and of the height to diameter ratio of the stem, a variable indicative of the competitive status of the tree. Simulations of the development of an individual knot showed that an increase in the stem radial growth rate was associated with an increase in the initial growth of the knot, but also with a shorter lifespan. Our results provide support for ‘Milton’s Law’, since they indicate that allocation priority is given to locations where the potential return is the highest. The developed models provided realistic simulations of knot morphology within trees, which could be integrated into a functional-structural model of tree growth and above-ground resource partitioning.

scholarly journals Maximum Branch Diameter in Black Spruce Following Partial Cutting and Clearcutting

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 913
Author(s):  
Audrey Lemay ◽  
Émilie Pamerleau-Couture ◽  
Cornelia Krause
Keyword(s):  
Black Spruce ◽  
Wood Quality ◽  
Additive Model ◽  
Stand Density ◽  
Maximum Diameter ◽  
Curvilinear Relationship ◽  
Partial Cutting ◽  
Branch Diameter ◽  
Branch Development ◽  
Final Harvest

Branch diameter is an important aspect of wood quality, as lumber grades can be determined based on the maximum diameter of branches. Crown and branch development can be influenced by the environment surrounding the trees, and silvicultural interventions, which reduce stand density and increase the growth of residual trees, could therefore alter branch properties. We evaluated maximum branch diameter within the crown of residual black spruce (Picea mariana (Mill.) B.S.P.) subjected to five types of silvicultural intervention—three partial-cutting and two clearcutting treatments—as well as trees within unmanaged control stands. We sampled a total of 41 stands and 223 trees. We collected 15 whorls from the live crown of each tree and measured the diameters of the largest branches. For all treatments, we observed a curvilinear relationship between maximum branch diameter and distance from the stem apex, and the largest branches were located in the lower third of the live crown. DBH before treatment and treatment were the variables that best explained maximum branch diameter in the lowest portion of the crown. A generalized additive model showed that maximum branch diameter in black spruce following silvicultural treatment will not differ significantly from trees of unmanaged control stands. Therefore, the studied partial cutting and clearcutting treatments do not have adverse effects on maximum branch diameter when compared to unmanaged control stands. However, DBH prior to treatment must be considered before any treatment is applied in forest management operations if maximum branch diameter is an important wood quality factor at the time of the final harvest of the stands.

scholarly journals A multiscale analysis of the effects of alternative silvicultural treatments on windthrow within balsam fir dominated stands

2015 ◽  
Vol 45 (12) ◽  
pp. 1739-1747 ◽  
Author(s):  
Kenneth Agbesi Anyomi ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Basal Area ◽  
Natural Disturbance ◽  
Balsam Fir ◽  
Partial Cutting ◽  
Selection Cutting ◽  
Silvicultural Treatments ◽  
Block Level ◽  
And Control

Boreal ecosystem functioning is largely controlled by disturbance dynamics. There have been efforts at adapting forest management approaches to emulate natural disturbance effects, as this is expected to maintain ecosystem resilience. In many instances, this involves resorting to partial cutting strategies that are likely to increase windthrow losses. The objective of this study was to determine the effects of alternative silvicultural practices on windthrow damage and how these effects vary with the scale of treatment. The study was conducted in the Quebec North Shore region (Canada), an area dominated by balsam fir (Abies balsamea (L.) Mill.) and accompanied by black spruce (Picea mariana (Mill) B.S.P.). Four different silvicultural treatments (overstory removal, heavy partial cutting, and two patterns of selection cutting) and control areas were implemented in 2004 and 2005. The experiment used a nested approach where treatment at the plot level was independent and yet nested within the block-level treatment. At the block level, treatments were applied over 10–20 ha units, leaving a small portion of the block for a smaller application of each treatment (plot scale, 2500 m2). Inventory was carried out before harvesting and monitoring was done yearly after harvesting, with the aim to better understand the plot- and block-level factors that drive windthrow damage levels and the effects of alternative silvicultural treatments. Results after 6–7 years show that basal area proportion windthrown differs substantially between treatments, as well as between treated sites and control sites. Windthrow levels were higher under heavy cuts relative to selection cuts and also increased with balsam fir proportion. Windthrow proportions were better correlated to block-level treatment than plot-level treatment, showing that the environment surrounding the treated plot can have an important effect on windthrow losses. Overall, the selection cutting system, particularly SC2, retains the most green-tree basal area and thus best meets the management objective of retaining old-growth attributes. A simple empirical model was calibrated that could aid in hazard rating.

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