Attributes of forest strips used by snowshoe hare in winter within clear-cut boreal landscapes

2005 ◽  
Vol 35 (10) ◽  
pp. 2521-2527 ◽  
Author(s):  
François Potvin ◽  
Normand Bertrand ◽  
Jean Ferron
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Snowshoe Hare ◽  
Forest Patches ◽  
Clear Cut ◽  
Important Prey ◽  
South Central ◽  
Snowshoe Hares ◽  
Riparian Strips

The snowshoe hare (Lepus americanus Erxleben) is an important prey for many predators in the boreal forest. In this biome, clear-cut landscapes are generally large and consist of aggregated cutting blocks separated by narrow forest strips (typically 60–100 m wide). To identify attributes of forest strips that are important for snowshoe hares, we measured the use of strips using track counts over two winters in six clear-cut landscapes (23–256 km2) in south-central Quebec. Surveys were conducted in 20 riparian strips (RS), 20 upland strips (US), and 15 control sites (CO) at the periphery of clear-cut landscapes. Overall, 392 signs of hare presence were recorded along 50 km of transects. Snowshoe hares were present in one-third of the strips surveyed and were five times less abundant in US and RS than in CO. The species avoided strip edges. Hares were more common in the wider strips (>100 m), in the strips adjacent to residual forest patches (≥25 ha), or in those having a denser shrub canopy, which is often associated with a greater basal area in balsam fir (Abies balsamea (L.) Mill.). To maintain snowshoe hare at moderate densities in large clear-cut landscapes, we suggest leaving uncut forest strips >100 m wide in areas having a good shrub cover with presence of balsam fir.

Mountain maple and balsam fir early response to partial and clear-cut harvesting under aspen stands of northern Quebec

2004 ◽  
Vol 34 (10) ◽  
pp. 2049-2059 ◽  
Author(s):  
Laurence Bourgeois ◽  
Christian Messier ◽  
Suzanne Brais
Keyword(s):  
Boreal Forests ◽  
Block Design ◽  
Management Strategies ◽  
Abies Balsamea ◽  
Basal Area ◽  
Early Response ◽  
Balsam Fir ◽  
Clear Cut ◽  
Canopy Opening ◽  
Slight Growth

This study is a component of the Sylviculture et aménagement forestier écosystémique project, which examines ecosystem-based forest management strategies in mixedwood boreal forests. Four harvesting treatments, one no-harvest, one clearcut, and two partial cuts (33% and 61% of basal area removed), were applied to even-aged aspen stands according to a complete block design. Mountain maple (Acer spicatum Lamb.) and balsam fir (Abies balsamea (L.) Mill.) early response was examined to understand how they react to and interact with canopy opening. Only in clearcuts was maple's response (increase in growth and density) sustained and significant. Balsam fir suffered from a very slight "growth shock" 1 year after harvesting in both clear-cut and two-thirds partial-cut treatments, but growth and vigour increased with canopy opening during the next 2 years. The first year following harvesting, balsam fir growth was negatively affected by understorey aspen and mountain maple. Our results show that the two-thirds partial harvesting treatment could speed up the conversion of pure aspen stands toward mixedwood.

AN ANALYSIS OF MEASURES OF DENSITY IN EVEN-AGED BALSAM FIR AND JACK PINE STANDS

1964 ◽  
Vol 40 (4) ◽  
pp. 474-481 ◽  
Author(s):  
P. E. Vezina
Keyword(s):  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Jack Pine ◽  
Balsam Fir ◽  
Aerial Photographs ◽  
Growing Stock ◽  
The One ◽  
Crown Closure

The concept of stand density in relation to thinning is examined and its development over the years is discussed. Present difficulties of objectively measuring stand density are recognized and probable future trends towards the development of better formulae to express stand density are outlined. Researchers should continue to collect information on interrelationships among stand variables. Certain merits accrue from description of stand density in terms of variables, such as crown closure, that can be measured with some precision from aerial photographs. Conversely, valid estimates of crown closure which are often difficult to obtain by means of devices from the ground, could be predicted from stand density. Three stand variables, used as expressions of stand density, were tested in crown closure simple regressions in even-aged, unmanaged stands of balsam fir (Abies balsamea (L.) Mill.) and jack pine (Pinus banksiana Lamb.). These are: total number of trees, number of trees 4 inches and up, and basal area per acre. The strongest relationship found was the one where crown closure is compared with basal area; it was stronger for jack pine than for balsam fir. This was explained by differences in tolerance among the two species. The significance of these relationships for the stand development, and the feasibility of using height-and diameter-based indices as measures of growing stock in studies of yield are discussed.

Riparian forest strips as habitat for snowshoe hare in a boreal balsam fir forest

1998 ◽  
Vol 28 (10) ◽  
pp. 1494-1500 ◽  
Author(s):  
Marcel Darveau ◽  
Jean Huot ◽  
Louis Bélanger
Keyword(s):  
Riparian Forest ◽  
Abies Balsamea ◽  
Timber Harvesting ◽  
Habitat Characteristics ◽  
Balsam Fir ◽  
Snowshoe Hare ◽  
Buffer Effect ◽  
Clear Cutting ◽  
Local Perturbations ◽  
Open Question

Riparian forest strips are usually protected from logging for their buffer effect on aquatic habitats. However, their value to terrestrial wildlife species such as snowshoe hare (Lepus americanus Erxleben) is unknown. From 1990 to 1996, we compared habitat characteristics (shrubs and saplings 0.25-2.25 m high), hare browsing, and hare pellet densities in five types of experimental riparian forest strips (20, 40, 60, and >300 m wide intact strips, and 20 m wide thinned strips), in a humid boreal balsam fir (Abies balsamea (L.) Mill.) landscape managed primarily for timber harvesting in Quebec. Based on coniferous and deciduous shrub densities, all riparian forest strips and adjacent clearcuts remained low-quality habitats for hare over 6 years following clear-cutting. Only 103 shrubs were browsed in a 1500-m2 area sampled over 3 years, of which only 33 had >20% of browsed stems. Nevertheless, pellet data revealed a low but sustained use of all strips each summer and winter, and there were no changes over 6 years (mean 280 pellets/ha per month; P > 0.05). Whether hare populations are cyclic or not in our region remains an open question. However, they show some fluctuations and timber harvesting coincided with "high" hare populations in our study area. Sampling in "low" years might show that fewer hares occupy the forest strips. Further work is required to determine the influence of regional and local perturbations on the use of riparian forest strips by snowshoe hares.

One and two years impact of commercial thinning on spruce budworm feeding ecology and host tree foliage production and chemistry

1996 ◽  
Vol 72 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Éric Bauce
Keyword(s):  
Choristoneura Fumiferana ◽  
Soluble Sugars ◽  
Abies Balsamea ◽  
Basal Area ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
First Year ◽  
Commercial Thinning ◽  
Mill Stand ◽  
Second Year

Field rearing experiments of spruce budworm, Choristoneura fumiferana (Clem.), were conducted in conjunction with foliar chemical analyses, one and two years after a commercial thinning (removal of 25% stand basal area) in a 50-year-old balsam fir, Abies balsamea (L.) Mill., stand. The first year after thinning, spruce budworm larvae reared on the residual trees developed five days faster and removed 43% more foliage than those reared on control trees, but in the second year they developed two days faster and removed 37% more foliage. The increase in larval development rate was related to an increase in foliar soluble sugars while a reduction in foliar monoterpenes caused by the thinning apparently accounted for the greater amount of foliage ingested by the larvae. The first year after thinning, trees were more vulnerable to spruce budworm because there was no increase in foliage production and the trees were more heavily defoliated. However, in the second year trees were less vulnerable to the insect because there was an increase in foliage production that exceeded the increase in defoliation, hence a net gain in foliage. Results from this study showed that commercial thinning could reduce the vulnerability of balsam fir trees to spruce budworm if thinning is conducted two years prior to budworm outbreak, but the same silvicultural procedure could increase the vulnerability to the insect if it is conducted during an outbreak. Key words: spruce budworm, balsam fir, chemistry, thinning, defoliation

scholarly journals Mortality Patterns Following Spruce Budworm Infestation in Unprotected Spruce-Fir Forests in Maine

2003 ◽  
Vol 20 (4) ◽  
pp. 148-153 ◽  
Author(s):  
Dale S. Solomon ◽  
Lianjun Zhang ◽  
Thomas B. Brann ◽  
David S. Larrick
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Growth Function ◽  
Red Spruce ◽  
Balsam Fir ◽  
Stem Density ◽  
Cumulative Mortality ◽  
Time Period ◽  
Composition Classes ◽  
Annual Mortality

Abstract Cumulative and annual mortality of red spruce (Picea rubens Sarg.) and balsam fir [Abies balsamea (L.) Mill.] were examined over a 10 yr period to follow the mortality patterns in unprotected spruce-fir forests in northern Maine. Different mortality patterns were determined based on stand composition classes and merchantability classes. In general, balsam fir was more vulnerable to budworm attack, and reached 92–100% basal area mortality and 84–97% stem density mortality 12 yr after the start of the outbreak. Red spruce, in contrast, had approximately 32–59% basal area mortality and 30–66% stem density mortality during the same time period. Balsam fir mortality started 1 to 2 yr before spruce, while spruce mortality continued 2 to 3 yr after fir mortality was completed. Higher mortality was found in smaller trees than sawtimber-sized trees. Stands with hardwood components (30–70% in basal area) had the lowest mortality rate for both species. Furthermore, Schnute growth function (Schnute 1981) was used to characterize the cumulative mortality trajectories after the defoliation of spruce and fir by stand composition classes. The models estimated the time when annual mortality achieved maximum, the cumulative mortality at that time, and the asymptotic mortality over a long time period after the start of the attack. The information can provide guidelines for predicting protection strategies and scheduling salvage harvests.

Fire return intervals and tree species succession in the North Shore region of eastern Quebec

2008 ◽  
Vol 38 (6) ◽  
pp. 1621-1633 ◽  
Author(s):  
Mathieu Bouchard ◽  
David Pothier ◽  
Sylvie Gauthier
Keyword(s):  
Tree Species ◽  
Forest Succession ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Geographic Variations ◽  
Forest Patches ◽  
The North ◽  
Species Succession ◽  
South Axis

We evaluated geographic variations in mean fire return intervals and postfire forest succession within a 66 497 km2 land area located in the eastern Quebec boreal forest. Fire return intervals were calculated using a time since last fire map for 1800–2000, and forest dynamics were studied by superimposing 3204 forest inventory plots onto the fire map. Mean fire return interval proved significantly shorter in the western part of the study area, at 270 years, compared with the eastern part, where it was probably more than 500 years. The two main tree species in the study area were balsam fir ( Abies balsamea (L.) P. Mill.) and black spruce ( Picea mariana (Mill.) BSP). Balsam fir abundance increased progressively as a function of time since fire, whereas black spruce abundance increased during the first 90 years after fire and then declined. Balsam fir was significantly more abundant in the southeastern portion of the study area, which we attribute to the combined limitations imposed by temperature along the north–south axis and by fire along the east–west axis. Large forest patches (i.e., ≥200 km2) dominated by early successional tree species, within a matrix of irregular black spruce – balsam fir mixtures, are an important feature of preindustrial forest landscapes in this region.

Recent impact of fire on high-altitude balsam fir forests in south-central Quebec1This article is one of a selection of papers from the 7th International Conference on Disturbance Dynamics in Boreal Forests.

2012 ◽  
Vol 42 (7) ◽  
pp. 1289-1305 ◽  
Author(s):  
Pierre-Luc Couillard ◽  
Serge Payette ◽  
Pierre Grondin
Keyword(s):  
High Altitude ◽  
Fire Regime ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Stand Age ◽  
Forest Types ◽  
Plant Composition ◽  
White Birch ◽  
South Central

The dynamics of high-altitude balsam fir ( Abies balsamea (L.) Mill.) forests is mainly driven by insect outbreaks and windthrows. However, very little work has been done on the role of fire on the development and maintenance of this ecosystem. In this study, we document the role of fire in the high-altitude balsam fir forests of the Réserve Faunique des Laurentides (RFL), southern Quebec. Sixteen sites were sampled among six different forest types described according to plant composition and fire evidence. At each site, the diameter structure was recorded and stand age was calculated based on tree-ring dating of individual trees and radiocarbon-dated surficial charcoal samples. Fire played a major role in the recent dynamics of high-altitude fir forests in the RFL. Over the last 250 years, nearly 50% of the study area burned during two fire conflagrations, i.e., around 1815 and in 1878. The fires triggered gradual changes in plant composition and forest structure, as shown by a succession of forest types ranging from white birch ( Betula papyrifera Marsh.) to spruce–fir types. Absence of surficial charcoal older than 300 years suggests that high-altitude forests of the RFL area were not subjected to a constant fire regime. It is possible that recent fires were caused by human activity.

scholarly journals Forest Succession Following a Spruce Budworm Outbreak in Minnesota

1985 ◽  
Vol 61 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Harold O. Batzer ◽  
Michael P. Popp
Keyword(s):  
Forest Succession ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Red Maple ◽  
Shrub Species ◽  
Before And After

Plots in 24 spruce-fir stands in northeastern Minnesota studied throughout the period 1957 to 1962 at the time of a spruce budworm outbreak were remeasured in 1979. Composition of the overstory changed from an average of 79% of the basal area in host species before to 31% after the budworm outbreak. Twelve percent of the stands showed growth in nonhost species that more than offset the loss in balsam fir and white spruce. The understory was minimally stocked with balsam fir in two-thirds of the stands. Only 4% of the regeneration was spruce. Even so, some well-established white spruce seedlings were found in two-thirds of the stands. Red maple was the most abundant hardwood invader. Raspberry, hazel and mountain maple were the principal shrub species limiting balsam fir reproduction Shrubs were most abundant in stands where balsam fir mortality had exceeded 80%. Half of the stands had seedlings that originated both before and after the outbreak; 45% had seedlings that originated only after the outbreak; and 5% had seedlings that originated only before the outbreak. Stands having moderate mixture of nonhost species in the over-story prior to the budworm outbreak had the most balsam fir regeneration. This resulted from seed produced by surviving balsam fir trees after the outbreak. Key words: Choristoneura fumiferana, Abies balsamea, Balsam fir, spruce-fir shrubs

Basal area and diameter growth in high-graded eastern temperate mixedwood forests: the influence of acceptable growing stock, species, competition and climate

2019 ◽  
Vol 92 (5) ◽  
pp. 659-669 ◽  
Author(s):  
Hugues Power ◽  
Patricia Raymond ◽  
Marcel Prévost ◽  
Vincent Roy ◽  
Frank Berninger
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Diameter Growth ◽  
Yellow Birch ◽  
Mixed Stands ◽  
Growing Stock ◽  
Mixedwood Forests ◽  
Stem Quality ◽  
History Of

AbstractHarvesting practices in temperate mixedwoods of eastern North America have a history of diameter-limit cuts, which have often resulted in degraded residual stands. In this study, we examined the factors influencing stand basal area (BA) and tree diameter growth in previously high-graded mixedwood forests, to understand which stands are more likely to recover from high-grading. Over 15 years, we monitored tree growth, recruitment and stem quality of 532 sample plots that were located in high-graded stands of Quebec’s mixedwood forest. We found that diameter growth rates were positively correlated with precipitation-related variables for balsam fir (Abies balsamea) and for yellow birch (Betulla alleghaniensis) but opposing trends for temperature-related variables were found. Conversely to balsam fir, yellow birch growth was positively correlated to temperature variables. Our results also show that BA growth was greater for plots with a larger acceptable growing stock (AGS: trees with potential sawlog production) and that the increase in AGS was greater for plots with larger amount of conifer BA. These result highlights the importance to maintain a proportion of conifer trees in these mixed stands. Moreover, the significant effect of asymmetric competition in our study underscores the relevance of considering the spatial distribution when choosing crop trees.

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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