Spatially explicit modeling of PAR transmission and growth of Picea glauca and Abies balsamea in the boreal forests of Alberta and Quebec

2005 ◽  
Vol 35 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Kenneth J Stadt ◽  
Victor J Lieffers ◽  
Ronald J Hall ◽  
Christian Messier
Keyword(s):  
Picea Glauca ◽  
Boreal Forests ◽  
Abies Balsamea ◽  
Height Growth ◽  
Growth Potential ◽  
Aerial Photographs ◽  
Spatially Explicit ◽  
Maximum Height ◽  
Eastern Canada ◽  
Functional Relationships

To investigate the feasibility of a spatially explicit, radiation-based regeneration model for the boreal forest, we tested the predictions of a three-dimensional simulator of photosynthetically active radiation transmission (%PAR), MIXLIGHT, and the growth response of understory Abies balsamea (L.) Mill. (balsam fir) and Picea glauca (Moench) Voss (white spruce) to %PAR in two large (>1 ha) mixed-species forest sites, one in eastern Canada at Lac Duparquet, Quebec, and one in western Canada at Calling Lake, Alberta. Overstory tree locations and dimensions were obtained from aerial photographs or ground measurements and allometric relationships. Seasonal %PAR calculated by MIXLIGHT for the Calling Lake site was very similar to seasonal %PAR measured by quantum sensors (n = 5, %PAR range = 15%–33%, r = 0.93). Daily measurements of %PAR were also predicted well by simulations at both sites (n = 34–36, %PAR range = 1%–45%, r ≥ 0.76). Functional relationships, designed to saturate at the maximum height growth potential of these sites, were developed to predict sapling height growth from simulated seasonal %PAR and initial height (R2 ≥ 0.74). These results demonstrate the potential of the MIXLIGHT simulator for estimating PAR at microsites within heterogeneous forests and for modeling understory tree growth.

Erratum: Spatially explicit modeling of PAR transmission and growth of Picea glauca and Abies balsamea in boreal forests of Alberta and Quebec

2006 ◽  
Vol 36 (5) ◽  
pp. 1342-1343
Author(s):  
Kenneth J Stadt ◽  
Victor J Lieffers ◽  
Ronald J Hall ◽  
Christian Messier
Keyword(s):  
Picea Glauca ◽  
Boreal Forests ◽  
Abies Balsamea ◽  
Spatially Explicit ◽  
Spatially Explicit Modeling

scholarly journals Preliminary Results from a Structural Conversion Thinning Trial in Eastern Canada

2020 ◽  
Vol 118 (5) ◽  
pp. 515-533
Author(s):  
Laurie Dupont-Leduc ◽  
Robert Schneider ◽  
Luc Sirois
Keyword(s):  
Picea Glauca ◽  
Stand Structure ◽  
Abies Balsamea ◽  
High Growth ◽  
Poor Quality ◽  
Growth Potential ◽  
Eastern Canada ◽  
Structural Conversion ◽  
Naturally Regenerated Stands ◽  
Regional Forest

Abstract In 2008, a thinning trial consisting in the removal of competitors around high growth potential stems (crop trees, CTs) was initiated as the first step of a structural conversion to transform even-aged stands into uneven-aged stands. Two intensities of thinning by CT release and thinning from below were tested in white spruce (Picea glauca [Moench] Voss) plantations and in balsam fir (Abies balsamea [L.] Mill)—dominated naturally regenerated stands. Unlike thinning from below, which aims to remove poor quality stems to improve the growth of residual trees, thinning by CT release aims to reduce competition between dominant trees. Trees thinned by CT release showed a significantly higher diameter at breast height increment than those in the control plots. CT release did not significantly increase stand structure, nor did it reduce stand growth, which helps to address the concerns of regional forest stakeholders. CT release may offer other benefits in the long term, but subsequent interventions are necessary to evaluate if this treatment meets the desired objectives.

scholarly journals An experimental study of how variation in deer density affects vegetation and songbird assemblages of recently harvested boreal forests

2012 ◽  
Vol 90 (6) ◽  
pp. 704-713 ◽  
Author(s):  
Etienne Cardinal ◽  
Jean-Louis Martin ◽  
Jean-Pierre Tremblay ◽  
Steeve D. Côté
Keyword(s):  
Picea Glauca ◽  
Boreal Forests ◽  
Forest Canopy ◽  
Forest Succession ◽  
Ecological Integrity ◽  
Abies Balsamea ◽  
Active Management ◽  
Large Herbivores ◽  
Clear Cutting ◽  
Deer Density

Intense browsing by abundant large herbivores can threaten the ecological integrity of ecosystems by inducing modifications in the structure and composition of vegetation that trigger trophic cascades affecting plant and animal communities. We investigated the relationships between density of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)), forest succession after clear-cut, and songbird communities on Anticosti Island, Quebec, Canada. We hypothesized that lower deer densities would alter the trajectory of forest succession after clear-cutting and lead to a rapid recovery of habitat attributes favorable to songbirds associated with a dense complex shrub layer. Six years after establishing a controlled browsing experiment (0, 7.5, 15, and >27 deer·km–2) in recent clearcuts, reducing deer densities ≤7.5 deer·km–2 initiated the restoration of balsam fir ( Abies balsamea (L.) Mill.) forests and increased the regeneration of paper birch ( Betula papyrifera Marshall). Increasing birch ground cover from 10% to 20% increased songbird total abundance, species richness, and diversity by 17%, 39%, and 31%, respectively. Alder Flycatcher (Empidonax alnorum Brewster, 1895) was only present at ≤7.5 deer·km–2 and strongly associated with birch regeneration. The regeneration of browse-resistant plants such as white spruce ( Picea glauca (Moench) Voss) in some areas at high deer density favored the maintenance of many shrub-dependent songbirds but also species usually associated with forest canopy. Active management of deer populations in Canadian harvested boreal forests will mitigate losses in vegetation and songbirds caused by over-browsing.

Early above- and below-ground responses of subboreal conifer seedlings to various levels of deciduous canopy removal

2006 ◽  
Vol 36 (8) ◽  
pp. 1891-1899 ◽  
Author(s):  
Yves Claveau ◽  
Philip G Comeau ◽  
Christian Messier ◽  
Colin P Kelly
Keyword(s):  
Picea Glauca ◽  
Abies Balsamea ◽  
Root Diameter ◽  
Height Growth ◽  
Stem Diameter ◽  
Abies Lasiocarpa ◽  
Size Dependent ◽  
Light Levels ◽  
Below Ground ◽  
Canopy Removal

We examined the growth of understory conifers, following partial or complete deciduous canopy removal, in a field study established in two regions in Canada. In central British Columbia, we studied the responses of three species (Pseudotsuga menziesii var. glauca (Beissn.) Franco, Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm., and Abies lasiocarpa (Hook.) Nutt.), and in northwestern Quebec, we studied one species (Abies balsamea (L.) Mill.). Stem and root diameter and height growth were measured 5 years before and 3 years after harvesting. Both root and stem diameter growth increased sharply following release but seedlings showed greater root growth, suggesting that in the short term, improvement in soil resource capture and transport, and presumably stability, may be more important than an increase in stem diameter and height growth. Response was strongly size dependent, which appears to reflect greater demand for soil resources as well as higher light levels and greater tree vigour before release for taller individuals. Growth ratios could not explain the faster response generally attributed to true fir species or the unusual swift response of spruces. Good prerelease vigour of spruces, presumably favoured by deciduous canopies, could explain their rapid response to release.

Chemical transformations of deadwood and foliar litter of mixed boreal species during decomposition

2012 ◽  
Vol 42 (4) ◽  
pp. 772-788 ◽  
Author(s):  
Manuella Strukelj ◽  
Suzanne Brais ◽  
Sylvie A. Quideau ◽  
Se-Woung Oh
Keyword(s):  
Chemical Composition ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Cupric Oxide ◽  
Abies Balsamea ◽  
Nuclear Magnetic Resonance Analysis ◽  
Chemical Transformations ◽  
Carbonyl Carbon ◽  
Important Input

Deadwood constitutes an important input of carbon to soil, but its role in carbon sequestration over the long term is not well documented in the eastern boreal forests of Canada, especially when compared with foliar litter. The objectives of this study were to characterize and compare patterns of mass loss and changes in chemical composition of deadwood and foliar litter of trembling aspen (Populus tremuloides Michx.), white spruce (Picea glauca (Moench) Voss), and balsam fir (Abies balsamea (L.) Mill.) during a 5- to 6-year period of field decomposition, using litterbags, solid-state 13C nuclear magnetic resonance analysis, and lignin monomer quantification by cupric oxide oxidation. The maximum decomposition limit was similar between foliar litter and wood material, but foliar litter decomposed faster, reached the estimated maximum decomposition limit, and converged to a composition rich in alkyl, phenolic, and carbonyl carbon. However, wood did not reach the estimated maximum decomposition limit and underwent relatively little chemical changes, remaining with high carbohydrate content. At the end of the experiment, aspen wood still had a lower lignin concentration than that of conifers, but contained higher proportions of alkyl and carbonyl carbon. Although wood contributes to a greater diversity in the chemical composition of the forest floor, foliar litter, which keeps a high alkyl C content throughout its decay, could generate more recalcitrant residual organic matter.

Height development of shade-tolerant conifer saplings in multiaged Acadian forest standsPublication 2954 of the Maine Agricultural and Forest Experiment Station, University of Maine, Orono, Maine.

2007 ◽  
Vol 37 (12) ◽  
pp. 2715-2723 ◽  
Author(s):  
Andrew R. Moores ◽  
Robert S. Seymour ◽  
Laura S. Kenefic
Keyword(s):  
Abies Balsamea ◽  
Growth Dynamics ◽  
Basal Area ◽  
Height Growth ◽  
Maximum Height ◽  
Conifer Species ◽  
Low Light ◽  
Light Levels ◽  
Time Period ◽  
Forest Experiment Station

Understory growth dynamics of northern conifer species were studied in four stands managed under multiaged silvicultural systems in eastern Maine. Height growth of Picea rubens Sarg., Abies balsamea (L.) Mill., and Tsuga canadensis (L.) Carr. saplings between 0.5 and 6.0 m in height was related to the proportion open sky (POS), using sapling height as a covariate. Height growth of T. canadensis equaled A. balsamea and exceeded P. rubens under very low light levels (POS < 0.1) but is much less responsive to both increasing POS and taller heights, reaching 50% of its maximum height growth at a POS of only 0.09. Abies balsamea outgrew P. rubens under similar dark conditions; at higher light levels (POS > 0.10), both species grew similarly. Evidently, no feasible overstory manipulation of light alone can promote more rapid height development of P. rubens saplings over A. balsamea. A nonlinear light-prediction model using stand basal area is linked with height-growth prediction equations to quantify sapling development from 0.5 to 6 m. Depending on overstory density, P. rubens requires a height advantage of 0.14–0.33 m over a 0.5 m tall A. balsamea to reach a height of 6 m over the same time period.

Sixty-year effects of deciduous removal on white spruce height growth and site index in the Western Boreal

2013 ◽  
Vol 43 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Diana E. Osika ◽  
Kenneth J. Stadt ◽  
Philip G. Comeau ◽  
Daniel A. MacIsaac
Keyword(s):  
Picea Glauca ◽  
White Spruce ◽  
Site Index ◽  
Height Growth ◽  
Growth Potential ◽  
Deciduous Trees ◽  
Mixed Stands ◽  
Boreal Plains ◽  
Age Model ◽  
Late Application

In the boreal plains of western Canada, white spruce (Picea glauca (Moench) Voss) height−age and site index (SI) curves have been developed and applied to assess site productivity for white spruce without fully considering the competition that usually occurs between the spruce and taller deciduous trees. In this study, we evaluated the effects of deciduous removal on white spruce height growth potential using stem analysis on typical control spruce grown with deciduous neighbours and spruce that were released from deciduous competition ∼60 years prior. Due to the late application of the release treatments (at stand ages of 20–60 years), the observed site index of spruce was not affected by treatment. However, height growth in the 50 years following treatment was increased by 2.1 m. We present a height−age model to specifically estimate the change in SI required to achieve the observed height response following late release. The model indicated that the post-release SI estimate of white spruce would need to be on average 4.2 m higher than control SI to track the height response. This model is useful for estimating the true, competition-free SI for white spruce from the observed SI in natural mixed stands.

Effects of climate on growth of lodgepole pine and white spruce following site preparation and its implications in a changing climate

2011 ◽  
Vol 41 (1) ◽  
pp. 180-194 ◽  
Author(s):  
Francesco Cortini ◽  
Philip G. Comeau ◽  
Jacob O. Boateng ◽  
Lorne Bedford ◽  
John McClarnon ◽  
...  
Keyword(s):  
Climate Change ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Height Growth ◽  
Site Preparation ◽  
Climate Variables ◽  
Boreal Zone ◽  
Vegetation Control

Site preparation and vegetation control can be used to mitigate climate change effects on early plantation growth in boreal forests. In this study, we explored growth of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and white spruce ( Picea glauca (Moench) Voss) in relation to climate and site preparation using 20 years of data collected from studies in British Columbia. Results indicate that up to 45% of the variation in spruce growth and up to 37% of the variation in pine growth over this 20-year period can be explained by selected climatic variables. Monthly climate variables showed a stronger relationship to conifer growth than seasonal and annual variables. Climate variables related to the preceding year accounted for more than half of the variables in the final equations, indicating a lagged response in conifer growth. Future projections indicated that height growth of young lodgepole pine plantations in the sub-boreal zone could benefit (in the short term) from longer growing seasons by up to 12% on untreated stands. Untreated young white spruce plantations in the boreal zone may suffer height growth decreases of up to 10% due to increased drought stress. Vegetation control and mechanical site preparation treatments appear to mitigate effects of climate change to some extent.

scholarly journals Growth dynamics of successive post-fire cohorts of black spruce: Is site potential reduced?

2014 ◽  
Vol 90 (01) ◽  
pp. 96-104 ◽  
Author(s):  
D. Côté ◽  
C. Lupi ◽  
R. Gagnon ◽  
D. Lord ◽  
H. Morin
Keyword(s):  
Boreal Forests ◽  
Forest Cover ◽  
Black Spruce ◽  
Growth Dynamics ◽  
Single Species ◽  
Nonparametric Test ◽  
Growth Potential ◽  
Eastern Canada ◽  
Mean Values ◽  
Cambial Age

Black spruce is one of the main commercial species in boreal forests of North America. It usually forms large and single-species natural stands in eastern Canada, yet in recent years, parts of this area have undergone forest cover regression and the conversion of closed-crown forests to open lichen woodlands, partly due to successive disturbances and regeneration accidents. We studied two successive post-fire cohorts growing at the same site, for which a clear forest cover regression trajectory has already been demonstrated, to assess possible changes in the site potential. The Wilcoxon nonparametric test found significant differences in mean diameter and height growth between cohorts, compared by cambial age, generally with higher mean values for the most recent cohort. There were no indications of growth reduction between the previous and the current cohorts. This paper sets the ball rolling for a discussion on the pertinence of reforestation in this type of recently established open formation, where growth potential (as expressed by diameter and height) seems, at least, maintained.

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