scholarly journals Radial Growth Response of Black Spruce Stands Ten Years after Experimental Shelterwoods and Seed-Tree Cuttings in Boreal Forest

Forests ◽  
2016 ◽  
Vol 7 (12) ◽  
pp. 240 ◽  
Author(s):  
Miguel Montoro Girona ◽  
Hubert Morin ◽  
Jean-Martin Lussier ◽  
Denis Walsh
2007 ◽  
Vol 37 (9) ◽  
pp. 1563-1571 ◽  
Author(s):  
H. C. Thorpe ◽  
S. C. Thomas ◽  
J. P. Caspersen

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.


1996 ◽  
Vol 13 (2) ◽  
pp. 68-72 ◽  
Author(s):  
Joanie Burns ◽  
Klaus J. Puettmann ◽  
Don Perala

Abstract Two different thinning methods were applied to three 6- or 7-yr-old black spruce stands in northern Minnesota which were measured after 20 yr. Overall, thinning improved the growing conditions for crop trees. Strip thinning with a 0.6 m leave strip and three widths of cleared strips (1.5 m, 2.1 m, and 2.7 m), and spacing to 1.5 m, 2.1 m, and 2.7 m resulted in reduced numbers of crop trees, but with larger diameters and, in the spacing thinned plots, greater heights. Because of these contradicting trends, stand volume was unaffected by thinning. Crop tree growth was not affected by the width of the cleared strip, but the distances between the leave trees in the square spacing were positively related to the increased growth response after thinning. The study is still too young to evaluate the economic feasibility of both thinning treatments, but shorter rotations or substantially increased volume seem possible by early thinnings of black spruce. North. J. Appl. For. 13(2):68-72.


Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 500 ◽  
Author(s):  
Audrey Lemay ◽  
Cornelia Krause ◽  
Alexis Achim

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.


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 333 ◽  
Author(s):  
Stephanie A. Jean ◽  
Bradley D. Pinno ◽  
Scott E. Nielsen

Research Highlights: Black spruce (Picea mariana Mill.) and trembling aspen (Populus tremuloides Michx.) both regenerated vigorously after wildfire. However, pure semi-upland black spruce stands are at increasing risk of changing successional trajectories, due to greater aspen recruitment. Background and Objectives: Black spruce and aspen are found across the boreal forest with black spruce dominating lowlands and aspen being common in uplands. Both species are well adapted to wildfire with black spruce holding an aerial seedbank while aspen reproduce rapidly via root suckering. In the summer of 2016, the Horse River wildfire burned 589,617 hectares of northern Alberta’s boreal forest. Methods: We assessed early regeneration dynamics of both pure aspen and pure black spruce forests. For black spruce, 12 plots were established in both bog and semi-upland habitats to assess seedling regeneration and seedbed availability. For aspen, 12 plots were established in each of the low, moderate, and high burn severities, as well as 5 unburned plots. Results: Post-fire black spruce regeneration densities did not differ between bog and semi-upland habitats, but were positively correlated with forb cover and charred organic matter seedbeds. Aspen regeneration within pure black sprue stands was substantial, particularly in semi-upland habitats, indicating a potential shift in successional trajectory. Fire severity did not significantly affect aspen regeneration in pure aspen stands, but regeneration density in all severity types was >90,000 stems ha−1. Aspen regeneration densities were negatively related to post-fire forb and shrub cover, likely due to competition and cooler soil temperature.


2010 ◽  
Vol 114 (7) ◽  
pp. 1494-1503 ◽  
Author(s):  
K. Barrett ◽  
E.S. Kasischke ◽  
A.D. McGuire ◽  
M.R. Turetsky ◽  
E.S. Kane

2004 ◽  
Vol 118 (1) ◽  
pp. 61 ◽  
Author(s):  
Jonathan D. Wright ◽  
Jessica Ernst

Wolverine (Gulo gulo luscus) caches and resting sites were examined in a study area in the boreal upland forests of northwestern Alberta and northeastern British Columbia (approximately 57°N). Cache sites were in climax, or “overmature” stands of Black Spruce (Picea mariana) or mixed-wood of high complexity, dominated by conifers, and in which the Trembling Aspen (Populus tremuloides) and Balsam Poplar (Populus balsamifera) component consisted of mostly dead or dying trees characteristic of such old growth in the boreal uplands. Sites offered relatively good visibility of the surrounding stand. Sites were never located in the dense to extremely dense homogenous spruce stands documented as being favored for travel by Wolverines in the study area. The better used cache complexes were accessed by numerous well-used trails made by the Wolverines themselves. Caches consisted of the bones, hide and hair of Moose (Alces alces) believed to have been killed by Grey Wolves (Canis lupus). Caches were classified as “simple caches” composed of a single feeding site and/or excavation and “cache complexes” involving one or more feeding “stations”, latrines, resting sites, and climbing trees that may have been used as avenues of escape from competitors/predators. Resting sites were located atop the snow in relatively open locations that offered good visibility of the surroundings. Climax stands were implicated as being of importance to Wolverine caching behavior. Conservation implications include the detrimental effect on Wolverine populations likely to result from current timber harvesting practices in the boreal forest.


2009 ◽  
Vol 85 (2) ◽  
pp. 267-276 ◽  
Author(s):  
Cornelia Krause ◽  
Hubert Morin ◽  
Pierre-Y. Plourde

In the boreal forest of Quebec, 80% of harvested black spruce (Picea mariana [Mill.] BSP) stands regenerate naturally. In the remaining 20%, forest regeneration is ensured by planting seedlings and these plantations are expected to increase future forest yields. However, predictions of future yields using the information from very young plantations in this ecosystem may have low accuracy. To compare juvenile growth in plantations versus naturally regenerated stands, and also to evaluate the impacts of spruce budworm Choristoneura fumiferana (Clemens) defoliation periods during the juvenile phase, annual height and volume growth were calculated from measurements on nine black spruce stands. The nine sites consisted of two plantations and seven post-fire, naturally regenerated stands. Of the seven naturally regenerated sites, four were epidemic and 3 endemic. The term “epidemic” refers to stands regenerated during known spruce budworm defoliation periods. The term “endemic” refers to stands regenerated during periods without severe defoliation. For height and volume growth, 5 different methods were used and compared. The annual height and volume growth of all black spruce showed a sigmoid trend, characterized by low values in the first years after germination, followed by an exponential acceleration and finally oscillation around a horizontal asymptote. The black spruce stands established during endemic periods were more productive than those established during epidemic periods, but plantations were the most productive. Key words: black spruce, juvenile growth, plantation, post-fire stands, spruce budworm outbreak, volume, yield


1979 ◽  
Vol 55 (5) ◽  
pp. 189-193 ◽  
Author(s):  
R. S. van Nostrand

Results are given for two NPK fertilizer trials established in 1967 and 1968 in 60-year-old black spruce stands in central Newfoundland. After nine years, replicated Trial 1 showed significant basal area and volume growth response over control for N, NP, NK and NPK treatments. N and NPK produced the greatest response where gains of 20 m3/ha and 23 m3/ha respectively were achieved after nine years. Similar results were obtained from non-replicated Trial 2 after eight years, where all treatments containing N produced approximately equal response. Maximum response in radial increment, measured from increment cores of sample trees, occurred four to six years after initial treatment. Generally, response was greater for dominant and co-dominant trees than for trees in the intermediate crown class.


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