scholarly journals A comparison of historical and current forest cover in selected areas of the Great Lakes–St. Lawrence Forest of central Ontario

2002 ◽  
Vol 78 (4) ◽  
pp. 522-529 ◽  
Author(s):  
Paul Leadbitter ◽  
David Euler ◽  
Brian Naylor
Keyword(s):  
Great Lakes ◽  
Forest Cover ◽  
Abies Balsamea ◽  
Timber Harvest ◽  
Selective Logging ◽  
Betula Alleghaniensis ◽  
Frequency Of Occurrence ◽  
White Birch ◽  
Group Frequency ◽  
Forest Managers

Crown survey notes from the late 1800s were used to reconstruct forest cover at that time in four forest management units in central Ontario, Canada. Historic forest cover was then compared to forest cover in 1990 based on Forest Resources Inventory (FRI) maps. Regional results indicate that the proportions of maple (Acer spp.) in the forest increased by 12.5%, while balsam fir (Abies balsamea) declined by 3.5%, hemlock (Tsuga canadensis) by 2.3% and other conifers (larch (Larix laricina) and cedar (Thuja occidentalis)) by 2.1%. The frequency of occurrence of maple, ash (Fraxinus spp.), yellow birch (Betula alleghaniensis), poplar (Populus spp.) and spruce (Picea spp.) also increased while white birch (Betula papyrifera), hemlock and other hardwoods (e.g., oak (Quercus spp.), basswood (Tilia americana), beech (Fagus grandifolia), elm (Ulmus spp.), ironwood (Ostrya virginiana) and black cherry (Prunus serotina Ehrh.)) declined. The region-wide proportional increase in maple is likely due to timber harvest techniques such as selective logging, effective fire suppression and the ecology of the maple species. Crown survey notes have been a useful tool in reconstructing presettlement forest cover. Survey notes can easily be obtained and used by forest managers and planners to understand presettlement conditions of this forest. Managers can achieve zero net loss of forest types in relation to the presettlement condition by using appropriate silvicultural practices to reduce the proportion of maple. Key words: Crown Survey records, presettlement forest, Great Lakes–St. Lawrence Forest, working group, frequency of occurrence

scholarly journals Gap dynamics in Balsam Fir, Abies balsamea - Yellow Birch, Betula alleghaniensis, forests of Québec

2009 ◽  
Vol 123 (2) ◽  
pp. 117 ◽  
Author(s):  
Rémi Hébert ◽  
Jean Huot
Keyword(s):  
Natural Regeneration ◽  
Forest Cover ◽  
Abies Balsamea ◽  
Woody Species ◽  
Balsam Fir ◽  
Regeneration Process ◽  
Betula Alleghaniensis ◽  
Gap Dynamics ◽  
Yellow Birch ◽  
Gap Characteristics

To determine if gap dynamics can play an important role in the natural regeneration process of Balsam Fir (Abies balsamea)-Yellow Birch (Betula alleghaniensis) forests and to determine the effects of gap characteristics on regenerating woody species, we sampled 119 gaps from 64 forest stands in La Mauricie National Park. Gaps averaged 184.5 m² in size. The mean gap age was 7.8 years. Gaps were usually created by broken or uprooted trees and only rarely resulted from Spruce Budworm (Choristoneura fumiferana) outbreaks. We found 25 species that regenerated in the gaps or under the forest cover. When considering all species, significantly more stems/ha were in gaps than under the forest cover. Gap characteristics generally did not influence regenerating woody species. We present a comprehensive model of gap dynamics in Balsam Fir-Yellow Birch forests, starting from a dense canopy, continuing with the creation and colonization of gaps, and ending to the closure of the canopy. Gap dynamics play an important role in the natural regeneration process of Balsam Fir-Yellow Birch forests.Afin de déterminer si la dynamique par trouée peut jouer un rôle important comme processus naturel de régénération de la sapinière à Bouleau Jaune et aussi afin de déterminer les effets des caractéristiques des trouées sur la régénération, nous avons échantillonné 119 trouées dans 64 peuplements forestiers au parc national de la Mauricie. Ces ouvertures avaient une superficie moyenne de 184,5 m². L’âge moyen des ouvertures était de 7,8 ans. Elles étaient généralement créées par un arbre cassé ou déraciné. Peu d’ouvertures étaient créées par des épidémies de la Tordeuse des Bourgeons de l’Épinette. Au total, 25 espèces en régénération ont été rencontrées dans les ouvertures ou sous le couvert forestier. En considérant toutes les espèces, il y avait significativement plus de tiges/ha dans les ouvertures que sous le couvert forestier. Les caractéristiques des trouées n’influençaient généralement pas la régénération. Nous présentons un modèle complet sur la dynamique par trouée dans la sapinière à Bouleau jaune, commençant avec une canopée dense, continuant avec la création et la colonisation des trouées, et se terminant avec la fermeture de la canopée. La dynamique par trouée joue un rôle important dans le régime de perturbations de la sapinière à Bouleau jaune.

Dynamique de la sapinière à bouleau jaune de l'est après une épidémie de tordeuse des bourgeons de l'épinette

1999 ◽  
Vol 75 (3) ◽  
pp. 515-534 ◽  
Author(s):  
Pierre Pominville ◽  
Stéphane Déry ◽  
Louis Bélanger
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
The Other ◽  
Balsam Fir ◽  
Betula Alleghaniensis ◽  
White Birch ◽  
Yellow Birch ◽  
Mixed Stands ◽  
The Dead

An outbreak of spruce budworm, Choristoneura fumiferana (Clem.), occurred between 1974 and 1987, in Quebec, in the eastern balsam fir, Abies balsamea (L.) Mill, - yellow birch, Betula alleghaniensis Britton, ecoclimatic sub-domain. The effect of this disruption has been assessed in mesic balsam fir stands killed during the outbreak, in mesic balsam fir stands partially damaged and in the following stands, also partially damaged: mesic yellow birch – balsam fir stands, mesic white birch, Betulapapyrifera Marsh., - balsam fir stands, mesic balsam fir – yellow birch stands, mesic balsam fir – white birch stands and xeric balsam fir stands. To that effect, surveys were led before, immediately after, and about five years after the outbreak in two blocks that have not been protected with insecticides. These blocks, located in Charlevoix and in Shipshaw management units, are second growth stands originating from clearcuts which occured about 50 years ago. Approximately five years after the outbreak, abundant coniferous regeneration was found everywhere except in the mesic yellow birch –balsam fir stand and in the dead mesic balsam fir stand, where softwood represented less than 50% of the regeneration. On the other hand, young softwood stems were located under the regeneration of white birch and of mountain maple, Acer spicatum Lam, in dead balsam fir stands, in balsam fir – white birch stands, as well as in living balsam fir stands and under mountain maple in yellow birch – balsam fir stands and in balsam fir – yellow birch stands. Our age structures indicate that softwood advance growth was relatively rare in these stands. Thus, during the opening of the canopy by the spruce budworm, intolerant hard-woods and shrubs invaded the still available microsites. In the dead balsam fir stands, stocking of the dominant hardwood regeneration stems is equivalent to that of softwood. Thus, dead balsam fir stands are turning to mixed stands. Xeric stands will remain softwood stands since they show luxuriant softwood regeneration dominating in height. In the other stands, we will have to wait the harvest period before we can adequately assess succession.

Calcium and magnesium in wood of northern hardwood forest species: relations to site characteristics

1999 ◽  
Vol 29 (3) ◽  
pp. 339-346 ◽  
Author(s):  
M A Arthur ◽  
T G Siccama ◽  
R D Yanai
Keyword(s):  
Sugar Maple ◽  
Abies Balsamea ◽  
Fagus Grandifolia ◽  
Hardwood Forest ◽  
Northern Hardwood Forest ◽  
Betula Alleghaniensis ◽  
Forest Species ◽  
White Birch ◽  
Yellow Birch ◽  
Northern Hardwood

Improving estimates of the nutrient content of boles in forest ecosystems requires more information on how the chemistry of wood varies with characteristics of the tree and site. We examined Ca and Mg concentrations in wood at the Hubbard Brook Experimental Forest. Species examined were the dominant tree species of the northern hardwood forest and the spruce-fir forest. The concentrations of Ca and Mg, respectively, in lightwood of these species, mass weighted by elevation, were 661 and 145 µg/g for sugar maple (Acer saccharum Marsh.), 664 and 140 µg/g for American beech (Fagus grandifolia Ehrh.), 515 and 93 µg/g for yellow birch (Betula alleghaniensis Britt.), 525 and 70 µg/g for red spruce (Picea rubens Sarg.), 555 and 118 µg/g for balsam fir (Abies balsamea (L.) Mill.), and 393 and 101 µg/g for white birch (Betula papyrifera Marsh.). There were significant patterns in Ca and Mg concentrations with wood age. The size of the tree was not an important source of variation. Beech showed significantly greater concentrations of both Ca (30%) and Mg (33%) in trees growing in moist sites relative to drier sites; sugar maple and yellow birch were less sensitive to mesotopography. In addition to species differences in lightwood chemistry, Ca and Mg concentrations in wood decreased with increasing elevation, coinciding with a pattern of decreasing Ca and Mg in the forest floor. Differences in Ca and Mg concentration in lightwood accounted for by elevation ranged from 12 to 23% for Ca and 16 to 30% for Mg for the three northern hardwood species. At the ecosystem scale, the magnitude of the elevational effect on lightwood chemistry, weighted by species, amounts to 18% of lightwood Ca in the watershed and 24% of lightwood Mg but only 2% of aboveground biomass Ca and 7% of aboveground Mg.

A comparison of pre-European settlement (1857) and current (1981-1995) forest composition in central Ontario

2000 ◽  
Vol 30 (4) ◽  
pp. 605-612 ◽  
Author(s):  
Scott M Jackson ◽  
Fred Pinto ◽  
Jay R Malcolm ◽  
Edward R Wilson
Keyword(s):  
Abies Balsamea ◽  
Detrended Correspondence Analysis ◽  
Forest Composition ◽  
Matched Pair ◽  
Small Scale ◽  
Betula Alleghaniensis ◽  
White Birch ◽  
White Cedar ◽  
Eastern White Cedar ◽  
Western Half

Presettlement forest composition along a 278 km long transect through central Ontario was recreated from Ontario land survey notes (1857) and compared with existing forest composition as derived from Forest Resource Inventories (1981-1995). Trends through time were analyzed by means of detrended correspondence analysis and univariate statistics (paired t tests and Wilcoxon matched-pair signed-ranks tests). Ordinations based on the first tree taxon listed in a stand and on all tree taxa provided similar results. The eastern half of the transect was initially dominated by boreal conifers, whereas the western half supported stands typical of Ontario's Great Lakes - St. Lawrence (GLSL) region. Significant reductions of yellow birch (Betula alleghaniensis Britt.), balsam fir (Abies balsamea (L.) Mill.), and eastern white cedar (Thuja occidentalis L.) and significant increases of poplar (Populus spp.) and white birch (Betula papyrifera Marsh.) were observed within the boreal half. A significant reduction in eastern white cedar and an increase poplar were observed in the western half. Changes in the boreal region strongly support previous studies conducted over shorter time periods and may be attributed to clear-cut harvesting. The persistence of shade-tolerant hardwoods within the GLSL region can be attributed to the prevalence of small-scale disturbances associated with partial-cut harvesting systems.

Un diagramme pollinique au Mont des Éboulements, région de Charlevoix, Québec

1976 ◽  
Vol 13 (1) ◽  
pp. 145-156 ◽  
Author(s):  
Pierre Richard ◽  
Philippe Poulin
Keyword(s):  
Populus Tremuloides ◽  
Sugar Maple ◽  
Abies Balsamea ◽  
Betula Alleghaniensis ◽  
White Birch ◽  
Yellow Birch ◽  
Pollen Diagram ◽  
Radiocarbon Dates ◽  
Pollen Influx ◽  
Dwarf Birch

The history of vegetation has been registered in the sediments of lake Mimi since about 11 000 BP, The initial vegetation traced is a tundra which, under severe climatic conditions, lasted for about 1000 years. The herb tundra was progressively replaced by shrub tundra: a willow phase (Salix). followed by a dwarf birch phase (Betula cf. glandulosa) have been traced. These were followed by an afforestation phase characterized by an aspen community (Populus tremuloides) al about 10 000 BP. Spruce succeeded the aspen community, probably as an open black spruce (Picea mariana) community with some dwarf birch and green alder (Alnus crispa). An outstanding Alnus cf. crispa pollen peak (48%), supported by the annual pollen influx values, at the end of the spruce phase, could be interpreted as a return of colder climate that favored the expansion of this shrub over forest. This event would date about 9750 BP. An open fir (Abies balsamea) forest followed, and changed to the balsam fir – white birch (Betula papyrifera) forest (climax domain), which prevailed until now. The richer sites supported sugar maple (Acer saccharum) – yellow birch (Betula alleghaniensis) community and fir – yellow birch stands since 6200 BP. Six radiocarbon dates and annual pollen influx values are offered, and some ecological problems related to the interpretation of the pollen diagram are discussed.

Succession forestière après feu dans la sapinière à bouleau jaune du Bas-Saint-Laurent, Québec

1997 ◽  
Vol 73 (6) ◽  
pp. 702-710 ◽  
Author(s):  
Louis Archambault ◽  
Jacques Morissette ◽  
Michèle Bernier-Cardou
Keyword(s):  
Populus Tremuloides ◽  
Sugar Maple ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Balsam Fir ◽  
Betula Alleghaniensis ◽  
Vegetation Composition ◽  
White Birch ◽  
Yellow Birch ◽  
Hardwood Species

Forest successions following a forest fire that occurred in 1932 were studied on mesic sites of the boreal mixedwood forest of the Bas-Saint-Laurent region of Quebec, Canada. Physiographic, soil and vegetation data were collected in 28 ecosystems distributed on a topographic gradient. The vegetation composition of the main canopy, 64 years after the fire, varied according to topographic situation. The proportion of tolerant hardwood species (yellow birch (Betula alleghaniensis Britton), sugar maple (Acer saccharum Marsh.), red maple (Acer rubrum L.)) increased toward upper slopes whereas it was the opposite for coniferous species (white spruce (Picea glauca [Moench] Voss), balsam fir (Abies balsamea [L.] Mill.)), as their proportion increased toward lower slopes. Intolerant hardwood species (white birch (Betula papyrifera Marsh.), trembling aspen (Populus tremuloides Michx.)) were abundant in all ecosystems. The distribution pattern of regeneration density and stocking of tolerant hardwoods and conifers was similar to that of the main canopy. The majority of commercial species, including tolerant species, established rapidly after the fire. Only eastern white cedar (Thuya occidentalis L.), which is a species typical of late succession, did not grow back. Ten years after the fire, 78% of the sampled dominant trees were established. Competition caused by mountain maple (Acer spicatum Lam.) did not seem to be as important after fire compared with the situation after clearcutting. Results showed that after the elimination of intolerant species, the vegetation composition should evolve toward the potential vegetation (climax) of the toposequence, that is, the sugar maple - yellow birch type on upper slopes, the balsam fir - yellow birch type on midslopes and the balsam fir - yellow birch - cedar type on lower slopes. Key words: succession, fire, yellow birch, balsam fir, mountain maple.

Portrait préindustriel dans un contexte de grande variabilité naturelle: une étude de cas dans le centre du Québec (Canada)

2011 ◽  
Vol 87 (05) ◽  
pp. 612-624 ◽  
Author(s):  
Eric Alvarez ◽  
Louis Bélanger ◽  
Louis Archambault ◽  
Frédéric Raulier
Keyword(s):  
Temperate Forest ◽  
Forest Cover ◽  
Sustainable Forest Management ◽  
Forest Succession ◽  
Black Spruce ◽  
Spatial Scales ◽  
White Birch ◽  
Industrial Landscape ◽  
Industrial Forest ◽  
Landscape Scales

Pre-industrial forest cover portrait is a recognized method for establishing the bases of sustainable forest management. However, it is a spatially and temporally dependant concept that should be used with caution in presence of big fires. The objective of the study was to portray the pre-industrial landscape in a mixedwood temperate forest in central Quebec at different spatial scales. The study was based on archival records from a forest company. The pre-industrial forest cover landscape of our study area was mainly composed of mature or old-growth (>100 years) stands and dominated by mixedwood forest stands with intolerant hardwoods. The main tree species were white birch, black spruce and jack pine, three species associated to forest succession after fire in the boreal forest. Considering the great variability caused by the fires and partial knowledge of this variability, for each spatial scale considered, we propose some management targets based on the main pre-industrial characteristics of this forest. To respect the pre-industrial variability, our study suggested that silviculture should be adapted at different landscape scales. Cover types and age class targets should be based on main preindustrial characteristics at each landscape scale analyzed.

Organohalogen Residues in Human Adipose Autopsy Samples from Six Ontario Municipalities

1988 ◽  
Vol 71 (2) ◽  
pp. 410-414 ◽  
Author(s):  
David T Williams ◽  
Guy L Lebel ◽  
Elizabeth Junkins
Keyword(s):  
Adipose Tissue ◽  
Great Lakes ◽  
Pesticide Residues ◽  
Human Adipose Tissue ◽  
Frequency Of Occurrence ◽  
Tissue Samples ◽  
Male And Female

Abstract Human adipose tissue samples obtained during autopsies in 6 Canadian Great Lakes municipalities were analyzed for chlorobenzenes, polychlorobiphenyls, and organohalogen pesticide residues. The frequency of occurrence and the range and mean for 2JJ organohalogen residues are reported for male and female donors in each municipality. Overall mean residue values in females were significantly higher than those in males for hexachlorobenzen;, β-HCH, p,p'- DDE,»,/» -DDD + o,p'-DDT, and p,p'-DDT. The means and ranges of residue values were similar to those reported in previous Canadian surveys.

Effects of fenitrothion on the arthropod food of tree-foraging forest songbirds

1990 ◽  
Vol 68 (11) ◽  
pp. 2235-2242 ◽  
Author(s):  
Rhonda L. Millikin
Keyword(s):  
Active Ingredient ◽  
Significant Relationship ◽  
Tree Species ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Betula Papyrifera ◽  
White Birch ◽  
Forest Songbirds ◽  
The Impact

The impact of fenitrothion on the arthropod food of songbirds was measured using white birch (Betula papyrifera Marsh.) and balsam fir (Abies balsamea (L.) Mill.) branch sample and drop trays. Following ground application of fenitrothion at 293 g active ingredient/ha, there was a significant decrease in the biomass of arthropods as determined using branch samples from both tree species, but not until 5 days after the application (29% reduction for balsam fir, 35% for white birch). Samples from drop trays indicated an immediate kill of arthropods not associated with the tree. Most remaining arthropods on treated balsam fir trees were dead. These dead arthropods would not be suitable food for birds that require movement to detect their prey. There was no significant relationship between amount of deposit (treated trees only) and the reduction of arthropods for either tree species.

Links between biomass and tree demography in a northern hardwood forest: a decade of stability and change in Hubbard Brook Valley, New Hampshire

2011 ◽  
Vol 41 (7) ◽  
pp. 1369-1379 ◽  
Author(s):  
Natalie S. van Doorn ◽  
John J. Battles ◽  
Timothy J. Fahey ◽  
Thomas G. Siccama ◽  
Paul A. Schwarz
Keyword(s):  
New Hampshire ◽  
Abies Balsamea ◽  
Total Biomass ◽  
Betula Alleghaniensis ◽  
Tree Biomass ◽  
Hubbard Brook ◽  
Tree Demography ◽  
Live Biomass ◽  
Live Tree ◽  
Annual Mortality

We resurveyed a network of sampling plots (n = 371) 10 years after its establishment in Hubbard Brook Experimental Forest (New Hampshire, USA) to quantify recent trends in tree biomass and demography. We found no significant change in live-tree biomass during the decade. Total biomass was 246 Mg·ha–1 (95%CI = 235–258) in 1995–1996 and 245 Mg·ha–1 (95%CI = 234–256) in 2005–2006. Annual mortality during the period for trees ≥ 10 cm diameter at breast height (1.37 m) averaged 9.7 trees·ha–1·year–1 (95% CI of annual mortality rate = 1.36%–1.84%·year–1). Tree recruitment into the census pool was 8.4 trees⋅ha–1·year–1 (95% CI = 5.8–10.6). Although overall forest biomass remained constant, there were marked shifts in the relative dominance of the canopy species. For example, the live biomass of Betula alleghaniensis Britton declined by 7%, whereas the live biomass of Picea rubens Sarg. increased by 6% and that of Acer saccharum Marshall increased by 4%. There was no instance of recruitment significantly exceeding mortality for the major species. Relative growth rates ranged from 1.03%·year–1 for Betula papyrifera Marshall to 1.99%·year–1 for Abies balsamea (L.) Mill. Our results confirmed earlier reports that the forest at Hubbard Brook is no longer aggrading. Current live-tree biomass is lower than expected. Although effects of novel disturbances documented on a regional level have not led to directional changes in tree demography at Hubbard Brook, we suggest that these novel stressors are depressing the biomass potential of the forest.

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