scholarly journals Litter-fall and decomposition in harvested and un-harvested boreal forests

2012 ◽  
Vol 88 (05) ◽  
pp. 613-621 ◽  
Author(s):  
M.T. Moroni ◽  
X. Zhu
Keyword(s):  
Litter Decomposition ◽  
Picea Mariana ◽  
Boreal Forests ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Forest Harvesting ◽  
Balsam Fir ◽  
Litter Fall ◽  
Feather Moss ◽  
Field Incubation

Litter fall and litter decomposition were examined in harvested and unharvested western Newfoundland balsam fir (Abies balsamea) and black spruce (Picea mariana) forests. Rates of litterfall in mature 70-year-old forests were 2.4 to 3.5 Mg ha−1 year−1, which was reduced to 0.2 to 0.3 Mg ha−1 year−1 following harvesting. In contrast, rates of black spruce needle, balsam fir needle, fine (<2 mm diameter) root, and moss (dominated by feather moss) litter decomposition were not affected by forest harvesting at either site during 24 to 54 months of field incubation in litterbags. Mass loss of balsam fir needle, black spruce needle, and moss (dominated by feather moss) were not significantly different indicating that moss forms a labile litter type in a forested setting.

Harvesting and slash piling affects soil respiration, soil temperature, and soil moisture regimes in Newfoundland boreal forests

2009 ◽  
Vol 89 (3) ◽  
pp. 343-355 ◽  
Author(s):  
M. T. Moroni ◽  
P. Q. Carter ◽  
D. A.J. Ryan
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Forest Harvesting ◽  
Balsam Fir ◽  
Minor Role ◽  
Respiration Rates ◽  
A Minor

The effect of harvesting and slash piling on soil respiration, temperature and moisture was examined in a balsam fir (Abies balsamea) and a black spruce (Picea marinara) forest located in western Newfoundland, Canada, 2 mo to 2.5 yr following harvesting. Within 4 mo of harvesting, soil temperature, moisture, and soil respiration rates were affected by harvesting and slash piling. Clearcut areas without slash (CC-S) had significantly lower soil respiration rates than uncut forests (F). However, clearcut areas with slash cover (CC+S) had significantly higher soil respiration rates than CC-S. When harvested areas with and without slash were combined, harvesting decreased soil respiration in the black spruce forest but had no effect on soil respiration in the balsam fir forest. Harvesting increased soil temperatures at 10 cm, however CC+S temperatures were cooler than CC-S temperatures. Harvested areas tended to dry faster than F, although soil moisture levels at >3.5 cm were not significantly depleted. However, there was evidence of soil drying at <3.5 cm. Soil temperature (at 10 cm) at the time of measurement was most strongly correlated to rates of soil respiration. Temporal variability and treatment effects (harvesting and slash piling) played a minor role in explaining soil respiration rates when variations in soil respiration were adjusted for 10-cm soil temperature,. Soil moisture levels (3.5-9.5 cm depth), which did not vary widely, also played a minor role in explaining soil respiration rates.Key words: Clearcut, Abies balsamea, Picea marinara, carbon dioxide, greenhouse gas

scholarly journals Vulnerability of Conifer Regeneration to Spruce Budworm Outbreaks in the Eastern Canadian Boreal Forest

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Janie Lavoie ◽  
Miguel Montoro Girona ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Management Strategies ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Insect Outbreaks ◽  
Spruce Stands ◽  
Canadian Boreal Forest

Spruce budworm (Choristoneura fumiferana) is the main defoliator of conifer trees in North American boreal forests, affecting extensive areas and causing marked losses of timber supplies. In 2017, spruce budworm affected more than 7 million ha of Eastern Canadian forest. Defoliation was particularly severe for black spruce (Picea mariana (Mill.) B.S.P.), one of the most important commercial trees in Canada. During the last decades, intensive forest exploitation practices have created vast stands of young balsam fir (Abies balsamea (L.) Mill.) and black spruce. Most research focused on the impacts of spruce budworm has been on mature stands; its effects on regeneration, however, have been neglected. This study evaluates the impacts of spruce budworm on the defoliation of conifer seedlings (black spruce and balsam fir) in clearcuts. We measured the cumulative and annual defoliation of seedlings within six clearcut black spruce stands in Quebec (Canada) that had experienced severe levels of defoliation due to spruce budworm. For all sampled seedlings, we recorded tree species, height class, and distance to the residual forest. Seedling height and species strongly influenced defoliation level. Small seedlings were less affected by spruce budworm activity. As well, cumulative defoliation for balsam fir was double that of black spruce (21% and 9%, respectively). Distance to residual stands had no significant effect on seedling defoliation. As insect outbreaks in boreal forests are expected to become more severe and frequent in the near future, our results are important for adapting forest management strategies to insect outbreaks in a context of climate change.

Predictions of wood density and module of elasticity of balsam fir (Abies balsamea) and black spruce (Picea mariana) from near infrared spectral analyses

2011 ◽  
Vol 41 (2) ◽  
pp. 352-358 ◽  
Author(s):  
Qinghua Xu ◽  
Menghua Qin ◽  
Yonghao Ni ◽  
Maurice Defo ◽  
Barbara Dalpke ◽  
...  
Keyword(s):  
Picea Mariana ◽  
Near Infrared ◽  
Prediction Models ◽  
Black Spruce ◽  
Microfibril Angle ◽  
Abies Balsamea ◽  
Weighted Average ◽  
Wood Properties ◽  
Balsam Fir ◽  
Green Wood

The predictions of properties for wood disc average are seldom reported, and they are important for sorting out logs based on their quality. The minimum near infrared (NIR) spectra required to predict wood disc average properties would also be of critical importance. In this study, calibration and prediction models for wood disc average properties were developed using NIR spectral data for balsam fir (Abies balsamea (L.) Mill.) and black spruce (Picea mariana (Mill.) B.S.P.) samples collected from 14 different sites across Newfoundland, Canada. The calibration was done against area-weighted average wood properties determined by SilviScan. NIR spectra were collected in 18 mm increments from the radial–longitudinal face of green and oven-dried samples. Results showed that using NIR spectra from three spots per wood strip was sufficient for the modeling and prediction for density and module of elasticity (MOE). The coefficients of determination ranged from 0.76 (MOE of green wood samples) to 0.88 (density of oven-dried wood samples). However, the microfibril angle (MFA) cannot be well predicted from either green wood or oven-dried wood NIR spectra. Our results further showed that the NIR spectra collected from oven-dried wood samples gave better calibration and prediction than those collected from green wood samples.

Marten use of clear-cuttings and residual forest stands in western Newfoundland

1987 ◽  
Vol 65 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Joyce E. Snyder ◽  
John A. Bissonette
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Primary Method ◽  
Forest Operations ◽  
Clear Cutting ◽  
Undisturbed Forest ◽  
Forest Habitats ◽  
Capture Rates

Marten (Martes americana) inhabit primarily old-growth coniferous and mixed wood forest habitats. Widespread forest harvest operations have prompted inquiries into whether residual patches of forest left after harvesting, or regenerating clear-cuttings, provide adequate habitat for marten. In western Newfoundland, the primary method of tree harvest has been clear-cutting of large tracts of balsam fir (Abies balsamea) and black spruce (Picea mariana). The only remaining populations of marten in the province also are found in the western part of the island, with greatest densities near Little Grand Lake. This study was designed to determine if marten used regenerating clear-cuttings and small remnant patches of residual forest left after forest operations. Habitat use by marten was investigated by livetrapping and snow tracking. Residual stands were classified into five size categories, and clear-cuttings into three categories based on height of balsam fir regeneration. From June to December 1983, marten were trapped in 43 residual stands and 35 clear-cuttings. A total of 3587 trap nights yielded 57 captures of 10 male and 8 female marten. Six (10.5%) captures were in clear-cuttings, all <15 years old; 51 (89.5%) marten were captured in residual stands. Capture rates were 0.48 captures/100 trap nights in the clear-cuttings and 2.19 captures/100 trap nights in residual stands. Capture rates were greatest in residual stands 25 to 34.9 ha in size (4.62 captures/100 trap nights). From January to March 1984, marten tracks were followed for 29 km. Although clear-cuttings represented 41 % of the study area, only 26% of marten travel was recorded there, all in clear-cuttings <15 years old. Residual stands >25 ha and undisturbed forest composed 41.3% of the study area; 41.8% of marten travel was recorded there. Smaller residual areas (<25 ha) made up only 4.2% of the total area, but 32.4% of the marten travel was recorded in these areas. These data indicate that marten seldom used clear-cuttings and used residual stands >25 ha and undisturbed forests in proportion to their occurrence, but the use of smaller residual stands <25 ha was greater than expected.

Comparing carbon pools and tree growth in balsam fir (Abies balsamea) and black spruce (Picea mariana) forest ecosystems located along a climatic gradient

Ecoscience ◽  
2014 ◽  
Vol 21 (3-4) ◽  
pp. 265-277 ◽  
Author(s):  
Guy R. Larocque ◽  
David Paré ◽  
Robert Boutin ◽  
Lamine Sarr ◽  
Valérie Lacerte ◽  
...  
Keyword(s):  
Tree Growth ◽  
Picea Mariana ◽  
Forest Ecosystems ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Carbon Pools ◽  
Climatic Gradient

FOREST COMMUNITIES IN NORTHWESTERN ALBERTA

1953 ◽  
Vol 31 (2) ◽  
pp. 212-252 ◽  
Author(s):  
E. H. Moss
Keyword(s):  
Populus Tremuloides ◽  
Black Spruce ◽  
Abies Balsamea ◽  
White Spruce ◽  
Balsam Fir ◽  
Peat Moss ◽  
Mixed Stands ◽  
Natural Succession ◽  
Balsam Poplar ◽  
Feather Moss

Spruce, tamarack (larch), balsam fir, pine, and poplar communities of the region are described in terms of floristic composition and ecological relationships. The white spruce (Picea glauca) association is regarded as the climax type of the region. Of four phases or faciations presented by the white spruce association, the feather moss faciation appears to be the climax to which the other faciations tend to develop. Two black spruce (Picea mariana) communities are recognized, the black spruce – feather moss association and the black spruce–peat moss association. Of these, the former is characterized by "feather mosses" such as Hylocomium splendens and has developed on relatively level terrain without much peat formation, whereas the latter has a Sphagnum floor and has arisen in definite depressions through acid bog stages with the production of considerable peat. The black spruce – bog moss community is interpreted as subclimax, with natural succession to the black spruce – feather moss association. The tamarack (Larix laricina) community has many features in common with the black spruce – peat moss association but differs markedly, not only in its dominant species, but because of its development from a Drepano-cladus–Carex–Betula bog under persisting wet conditions. Succession to black spruce commonly occurs. Balsam fir (Abies balsamea) is relatively rare in the region and usually grows in mixed stands with white spruce, paper birch, aspen, and balsam poplar. Two divisions of the pine association are recognized, the jack pine (Pinus banksiana) and the lodgepole pine (P. contorta var. latifolia) consociations. For each of these, two phases are described, the pine – feather moss faciation on the more shaded sites and the pine–heath faciation on the more open and drier areas. Knowledge of the ranges of these two pines in northern Alberta and concerning hybrids between the species is extended. The poplar association, classified as aspen (Populus tremuloides) and balsam poplar (P. balsamifera) consociations, is considered in relation to other vegetation, especially prairie grassland and white spruce. Encroachment of aspen poplar upon native grassland is counteracted by various factors, notably burning. Natural succession of poplar and pine to white spruce is impeded chiefly by forest fires. Some attention is given to phytogeographical problems of this transition region.

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