Long-term fire and forest history of subalpine balsam fir (Abies balsamea) and white spruce (Picea glauca) stands in eastern Canada inferred from soil charcoal analysis

Extensive balsam fir (Abies balsamea (L.) Mill.) stands across the southern boreal forest are ecosystems likely more influenced by insect outbreaks and windthrows than by fire. To what degree the dominance of balsam fir stands reflects past and present disturbance dynamics associated with fire is not well documented. To answer this question, we focused on the reconstruction of the long-term fire history of high-altitude balsam fir forests of southern Quebec. The reconstruction was based on botanically identified and radiocarbon-dated soil charcoal particles in 19 sites covering successional stages from white birch (Betula payrifera Marsh.) to mixed white birch – balsam fir stands. Fire activity commenced early after deglaciation, about 9600 calibrated years before present when the first boreal tree species were established. Fire occurred recurrently during the following 5000 years with a forest landscape composed of the principal tree species common to the boreal forest, including jack pine (Pinus banksiana Lamb.). Fire activity ceased more or less abruptly about 4500 years ago due to less fire-conducive, more humid conditions. Then, the forest landscape progressively changed towards a larger representation of white birch – balsam fir forests and the disappearance of jack pine. Whereas several balsam fir stands have not burned over the last 4500 years, scattered fires occurred in particular over the last 250 years when 1815 and 1878 fires, probably man-made, burned 50% of the forest, thus causing a major change in the composition of the forest landscape. It is concluded that the high-altitude forest landscape of southern Quebec changed profoundly over the Holocene in close association with a time-transgressive dry-to-wet climatic gradient.

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Windthrow as an important process for white spruce regeneration

The Forestry Chronicle ◽

10.5558/tfc78732-5 ◽

2002 ◽

Vol 78 (5) ◽

pp. 732-738 ◽

Cited By ~ 13

Author(s):

Jean-Claude Ruel ◽

Marius Pineau

Keyword(s):

Key Words ◽

Picea Glauca ◽

Abies Balsamea ◽

White Spruce ◽

Balsam Fir ◽

Differential Mortality ◽

Important Process ◽

Mature Stands

White spruce (Picea glauca (Moench.) Voss.) is frequently found in association with balsam fir (Abies balsamea (L.) Mill.) in virgin stands. However, its regeneration is less aggressive than that of balsam fir. The persistance of white spruce in the canopy might be explained by differential mortality and windthrow. Windthrow could play an important role in creating favourable seedbeds and providing increased light. This paper examines the contribution of windthrow for white spruce regeneration in balsam fir-dominated forests. Experimental windthrows were created and regeneration establishment monitored for three seasons. Windthrow greatly modified the availability of seedbeds and enhanced white spruce establishment. Older natural windthrows were sampled to conclude that this effect was still evident more than five years after windthrow occured. We also noticed that white spruce benefited more from the disturbance than did balsam fir. Finally, sampling conducted in mature stands showed that mature white spruce stems were more abundant on the mounds created by old uprootings, indicating that this effect is maintained in the long term. Even though balsam fir also benefited from windthrow, the benefit was proportionally greater for white spruce. Key words: Picea glauca, Abies balsamea, windthrow, microtopography, regeneration

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The Mediterranean Old-Growth Forests: Anomalies or Relicts? The Contribution of Soil Charcoal Analysis

Forests ◽

10.3390/f12111541 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1541

Author(s):

Vincent Robin ◽

Stefan Dreibrodt ◽

Brigitte Talon

Keyword(s):

Abiotic Factors ◽

Charcoal Analysis ◽

Old Growth ◽

Biotic And Abiotic Factors ◽

Soil Charcoal ◽

Old Growth Forest ◽

Mediterranean Landscapes ◽

Old Growth Forests ◽

Soil Charcoal Analysis

Old-growth forests are of high interest for biodiversity conservation, especially in the disturbance-prone Mediterranean landscapes. However, it remains unclear whether the survival of patches of old-growth forest in the degraded Mediterranean landscapes results from local anomalies or from past, larger forests. Therefore, in this study, we assessed (1) the origin, (2) the long-term ecological trajectory, and (3) the mechanism(s) that explain the survival of a Mediterranean old-growth forest, the Sainte-Baume forest. To achieve this, we used soil charcoal analysis. We opened fifteen soil profiles in the forest and five in its surrounding areas for soil description and sampling. The soil descriptions enabled us to highlight in situ soil horizon and colluvial layers. A total of 1656 charcoal pieces from different soil samples were taxonomically identified to characterize the composition of past forests. Selected charcoal pieces (n = 34) were dated to obtain chronological data. Our investigations indicate that the survival of the Mediterranean old-growth forest, in the context of the semi-open/open Mediterranean landscapes, is the result of a combination of biotic and abiotic factors, which reduced the influence of past forest disturbances. Thus, the resistance and resilience of the forest areas are preserved over a long-term ecological trajectory. Therefore, the potential of Mediterranean old-growth forests as baseline reference points for the conservation of biodiversity is related to the identification and maintenance of the local biotic and abiotic factors which allowed the survival of the old-growth forest.

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Reproductive potential of balsam fir (Abies balsamea), white spruce (Picea glauca), and black spruce (Picea mariana) at the ecotone between mixedwood and coniferous forests in the boreal zone of western Quebec

American Journal of Botany ◽

10.3732/ajb.94.5.1 ◽

2007 ◽

Vol 94 (5) ◽

pp. 1-10

Author(s):

Y. Messaoud ◽

Y. Bergeron ◽

H. Asselin

Keyword(s):

Picea Mariana ◽

Picea Glauca ◽

Black Spruce ◽

Reproductive Potential ◽

Abies Balsamea ◽

White Spruce ◽

Balsam Fir ◽

Coniferous Forests ◽

Boreal Zone

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LONG TERM STUDY OF THE EFFECTIVENESS OF AERIAL APPLICATION OF BACILLUS THURINGIENSIS – ACEPHATE COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

The Canadian Entomologist ◽

10.4039/ent1091239-9 ◽

1977 ◽

Vol 109 (9) ◽

pp. 1239-1248 ◽

Cited By ~ 15

Author(s):

O. N. Morris

Keyword(s):

Bacillus Thuringiensis ◽

Choristoneura Fumiferana ◽

Larval Mortality ◽

Abies Balsamea ◽

Spruce Budworm ◽

White Spruce ◽

Balsam Fir ◽

Population Densities ◽

Long Term Study

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.

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Black spruce decline triggered by spruce budworm at the southern limit of lichen woodland in eastern Canada

Canadian Journal of Forest Research ◽

10.1139/x01-160 ◽

2001 ◽

Vol 31 (12) ◽

pp. 2160-2172 ◽

Cited By ~ 22

Author(s):

Martin Simard ◽

Serge Payette

Keyword(s):

Black Spruce ◽

Abies Balsamea ◽

Spruce Budworm ◽

Jack Pine ◽

Growth Patterns ◽

Balsam Fir ◽

Eastern Canada ◽

Southern Limit ◽

Epiphytic Lichen ◽

Spruce Decline

Black spruce (Picea mariana (Mill.) BSP) is the dominant tree species of the southernmost (48°N) lichen woodlands in eastern Canada. Most spruce trees in mature lichen woodlands appear to be declining, as shown by the massive invasion of the epiphytic lichen Bryoria on dead branches of dying trees. A dendroecological study was undertaken to identify the main causal factors of the decline. A decline index based on the abundance of Bryoria on spruce trees was used to distinguish healthy from damaged lichenspruce woodlands and to select sampling sites for tree-ring measurements. Three conifer species (black spruce, balsam fir (Abies balsamea (L.) Mill.), and jack pine (Pinus banksiana Lamb.)) were sampled to compare their growth patterns in time and space. In the late 1970s and mid-1980s, black spruce and balsam fir experienced sharp and synchronous radial-growth reductions, a high frequency of incomplete and missing rings, and mass mortality likely caused by spruce budworm (Choristoneura fumiferana (Clem.)) defoliation. Jack pine, a non-host species, showed no such trend. Because black spruce layers were spared, lichen woodlands will eventually regenerate unless fire occurs in the following years. Black spruce decline can thus be considered as a normal stage in the natural dynamics of the southern lichen woodlands.

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Long-term outcome of precommercial thinning in northwestern New Brunswick: growth and yield of balsam fir and red spruce

Canadian Journal of Forest Research ◽

10.1139/x07-132 ◽

2008 ◽

Vol 38 (3) ◽

pp. 592-610 ◽

Cited By ~ 39

Author(s):

Doug Pitt ◽

Len Lanteigne

Keyword(s):

Block Design ◽

Abies Balsamea ◽

Red Spruce ◽

Balsam Fir ◽

Growth And Yield ◽

Stem Volume ◽

Long Term Outcome ◽

Precommercial Thinning ◽

Minimum Requirement

A study was established between 1959 and 1961 to study the long-term responses of balsam fir ( Abies balsamea (L.) Mill.) and red spruce ( Picea rubens Sarg.) to precommercial thinning. Three nominal spacings of 4 ft (1.2 m), 6 ft (1.8 m), and 8 ft (2.4 m) were compared with an unthinned control in a randomized complete block design with five replicates. At the time of thinning, natural regeneration averaged 16 years of age, 8 years after harvest. Although thinning had minimal effect on gross total volume production over a 42 to 44 year observation period, actual spacings between 2.1 and 2.5 m produced an average of 360 m3·ha–1gross merchantable volume (GMV), representing a 21% gain over unthinned stands. The same spacings produced quadratic mean diameters of 21 and 23 cm, respectively, compared with 18 cm in the unthinned stands. These size increases translated to individual stem volume gains of 33% and 62%, significantly reducing the age at which thinned stands would meet a specified minimum requirement for merchantability or habitat. The mean annual increment of GMV ranged from 6 m3·ha–1·year–1in unthinned stands, to more than 7 m3·ha·–1·year–1in the thinned stands, and had not yet culminated an average of 50 years postharvest.

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Trends in the frequency, extent, and severity of spruce budworm outbreaks in eastern Canada

Canadian Journal of Forest Research ◽

10.1139/x83-079 ◽

1983 ◽

Vol 13 (4) ◽

pp. 539-547 ◽

Cited By ~ 264

Author(s):

J. R. Blais

Keyword(s):

20Th Century ◽

Large Scale ◽

Spruce Budworm ◽

Forest Composition ◽

Eastern Canada ◽

Clear Cutting ◽

The Past ◽

Spruce Stands ◽

History Of

The history of spruce budworm (Choristoneurafumiferana (Clem.)) outbreaks for the past 200 to 300 years, for nine regions in eastern Canada, indicates that outbreaks have occurred more frequently in the 20th century than previously. Regionally, 21 outbreaks took place in the past 80 years compared with 9 in the preceding 100 years. Earlier infestations were restricted to specific regions, but in the 20th century they have coalesced and increased in size, the outbreaks of 1910, 1940, and 1970 having covered 10, 25, and 55 million ha respectively. Reasons for the increase in frequency, extent, and severity of outbreaks appear mostly attributable to changes caused by man, in the forest ecosystem. Clear-cutting of pulpwood stands, fire protection, and use of pesticides against budworm favor fir–spruce stands, rendering the forest more prone to budworm attack. The manner and degree to which each of these practices has altered forest composition is discussed. In the future, most of these practices are expected to continue and their effects could intensify, especially in regions of recent application. Other practices, including large-scale planting of white spruce, could further increase the susceptibility of forest stands. Forest management, aimed at reducing the occurrence of extensive fir–spruce stands, has been advocated as a long-term solution to the budworm problem. The implementation of this measure at a time when man's actions result in the proliferation of fir presents a most serious challenge to forest managers.

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