Canopy gap disturbance and succession in trembling aspen dominated boreal forests in northeastern Ontario

2005 ◽  
Vol 35 (8) ◽  
pp. 1942-1951 ◽  
Author(s):  
Steven B Hill ◽  
Azim U Mallik ◽  
Han YH Chen
Keyword(s):  
Populus Tremuloides ◽  
Boreal Forests ◽  
Abies Balsamea ◽  
Stand Development ◽  
Gap Size ◽  
Trembling Aspen ◽  
Gap Fraction ◽  
Gap Disturbance ◽  
The Impact ◽  
Development Proceeds

Canopy gaps play an important role in forest vegetation dynamics when fire return intervals are long. However, there is little known about the role of gaps in the development of forest stands that initially dominate following stand-replacing disturbance. We investigated gap disturbance during the breakup of trembling aspen (Populus tremuloides Michx.) stands at two scales: at the stand level we quantified gap fraction and gap size as stand development proceeds; at the gap level we determined causes of gap-maker mortality and evaluated resulting gap-maker structure and decay as stand development proceeds. We also evaluated the impact that gaps have on stand transition by quantifying the abundance and growth of juvenile trees in gaps of different sizes and ages. Ten stands between 60 and 120 years since fire in northeastern Ontario were sampled using line intersect transects. Gap fraction doubled (∼18%–36%) and mean gap size was more than four times greater (∼45–200 m2) over the time period. Standing dead gap makers in early states of decay were most frequent in young stands, whereas snapped gap makers in various states of decay were most frequent in old stands. Infection by fungal pathogens was the most frequent cause of mortality (56%) and was not related to time since fire. Balsam fir (Abies balsamea (L.) Mill.) was the most abundant juvenile recruit. However, transition probabilities for tree species were independent of gap type. These results indicate that gap creation is frequent during early stages of stand development in boreal forests; however, it is unlikely that successional trajectory is affected by their formation.

scholarly journals Evaluating the Performance of a Forest Succession Model to Predict the Long-Term Dynamics of Tree Species in Mixed Boreal Forests Using Historical Data in Northern Ontario, Canada

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1181
Author(s):  
Guy R. Larocque ◽  
F. Wayne Bell
Keyword(s):  
Populus Tremuloides ◽  
Boreal Forests ◽  
Forest Ecosystems ◽  
Forest Succession ◽  
Regional Scale ◽  
Abies Balsamea ◽  
Forest Growth ◽  
Northern Ontario ◽  
Phase Dynamics

Environmental concerns and economic pressures on forest ecosystems have led to the development of sustainable forest management practices. As a consequence, forest managers must evaluate the long-term effects of their management decisions on potential forest successional pathways. As changes in forest ecosystems occur very slowly, simulation models are logical and efficient tools to predict the patterns of forest growth and succession. However, as models are an imperfect representation of reality, it is desirable to evaluate them with historical long-term forest data. Using remeasured tree and stand data from three data sets from two ecoregions in northern Ontario, the succession gap model ZELIG-CFS was evaluated for mixed boreal forests composed of black spruce (Picea mariana [Mill.] B.S.P.), balsam fir (Abies balsamea [L.] Mill.), jack pine (Pinus banksiana L.), white spruce (Picea glauca [Moench] Voss), trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.), northern white cedar (Thuja occidentalis L.), American larch (Larix laricina [Du Roi] K. Koch), and balsam poplar (Populus balsamefera L.). The comparison of observed and predicted basal areas and stand densities indicated that ZELIG-CFS predicted the dynamics of most species consistently for periods varying between 5 and 57 simulation years. The patterns of forest succession observed in this study support gap phase dynamics at the plot scale and shade-tolerance complementarity hypotheses at the regional scale.

Potential for combining sex pheromones for the forest tent caterpillar (Lepidoptera: Lasiocampidae) and the large aspen tortrix (Lepidoptera: Tortricidae) within monitoring traps targeting both species

2005 ◽  
Vol 137 (5) ◽  
pp. 615-619 ◽  
Author(s):  
Maya L. Evenden
Keyword(s):  
Populus Tremuloides ◽  
Economic Value ◽  
Malacosoma Disstria ◽  
Forest Tent Caterpillar ◽  
Trembling Aspen ◽  
Commercially Important ◽  
Monitoring Traps ◽  
The Impact ◽  
Tent Caterpillar ◽  
Choristoneura Conflictana

Trembling aspen, Populus tremuloides Michx. (Salicaceae), is the most widely distributed tree species in North America (Perala 1990) and is considered to be an ecologically (Hogg et al. 2002) and economically important (Brandt et al. 2003) component of the boreal forest. Due to the recently increased economic value of trembling aspen (Brandt et al. 2003), the impact of native insect defoliators on tree growth and mortality has become commercially important. Two of the most significant defoliators of trembling aspen throughout its range in Canada are the forest tent caterpillar (FTC), Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), and the large aspen tortrix (LAT), Choristoneura conflictana Walker (Lepidoptera: Tortricidae).

Partial cuts in a trembling aspen – conifer stand: effects on microenvironmental conditions and regeneration dynamics

2003 ◽  
Vol 33 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Marcel Prévost ◽  
David Pothier
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
Basal Area ◽  
Trembling Aspen ◽  
Limited Growth ◽  
Growth And Survival ◽  
Regeneration Dynamics ◽  
Canopy Opening ◽  
Light Soil

We present the 5-year combined effects of different cutting intensities (removal of 0, 35, 50, 65, and 100% of basal area) and scarification on available light, soil temperature, and regeneration dynamics in a mixed aspen– conifer stand in Quebec, Canada. Compared with the control, the 35% cut did not change transmitted light to the under story (<20% of full light), while the 50, 65, and 100% cuttings transmitted 30, 48, and 90% of full light, respectively, during the first summer. Trembling aspen (Populus tremuloides Michx.) suckering increased with percent basal area removal (p < 0.001). After 5 years, the 35 and 50% cuttings limited growth and survival of suckers (<1000 stems/ha, of which 5% are >1 m high), but the 65 and 100% cuttings favoured their development (8000 and 11 000 stems/ha, respectively, of which 29 and 38%, respectively, are >2 m high). Balsam fir (Abies balsamea (L.) Mill.) responded well to canopy opening alone with a maximal recruitment (31 000 seedlings/ha) in the 50% cut. Spruces (white spruce, Picea glauca (Moench) Voss, and red spruce, Picea rubens Sarg.) establish following scarification only, with a better response in the 65% cut (32 000 seedlings/ha) than in the 50 (15 000), 35 (10 000), and 0% (8000) cuttings.

Variations, selon la progression de l'hiver, dans le choix de l'habitat et du régime alimentaire chez trois groupes d'orignaux (Alces alces) en milieu agro-forestier

1986 ◽  
Vol 64 (7) ◽  
pp. 1475-1481 ◽  
Author(s):  
Robert Joyal ◽  
Claude Bourque
Keyword(s):  
Populus Tremuloides ◽  
Snow Depth ◽  
Alces Alces ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Régime Alimentaire ◽  
Trembling Aspen ◽  
Plant Composition ◽  
Core Areas ◽  
Settlement Areas

Three distinct groups of moose (Alces alces) were followed for one winter in settlement areas of northwestern Quebec to investigate changes in their choice of diet and habitat over the winter. No trend was observed in structure and plant composition of winter yards over the season. From December to March, each group used at least three different core areas intensively, these areas totalling 1.02 (first group), 1.28 (second group), and 2.48 km2 (third group). The size of the winter yards diminished in March but this decrease was not due to an increase in snow depth, which reached its maximum of 88 cm in February. The total areas used by the three groups were 1.7, 2.6, and 6.6 km2, respectively. No trend was found in the diet during the winter, except that trembling aspen (Populus tremuloides) was most heavily used by the three groups in March. Twenty-three species of browse were used but 6 species formed nearly 95% of the diet; balsam fir (Abies balsamea) and mountain maple (Acer spicatum) were almost completely absent from the diet.

Examining 40-year stand development following vegetation control: white spruce planted in a trembling aspen dominated cutover

2011 ◽  
Vol 41 (4) ◽  
pp. 728-739 ◽  
Author(s):  
Robert L. Fleming ◽  
Allister D. Smith
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
White Spruce ◽  
Growth Patterns ◽  
Stand Development ◽  
Trembling Aspen ◽  
Herbicide Application ◽  
Vegetation Control ◽  
Mechanical Site Preparation ◽  
Age Shift

Many of the major questions regarding stand establishment practices involve implications for longer-term ecosystem development. We examined 41-year treatment effects on stand composition and dynamics using a white spruce ( Picea glauca (Moench) Voss) planting, mechanical site preparation (MSP) – herbicide (2,4-D plus 2,4,5-T) trial in a trembling aspen ( Populus tremuloides Michx.) dominated mixedwood. Both barrel and blade MSP with planting increased total and white spruce year 41 stand-level biomass over that in untreated areas. Year 2 herbicide application reduced year 41 trembling aspen biomass without substantially increasing that of white spruce, resulting in total yields similar to those in untreated areas. Barrel MSP increased year 41 trembling aspen biomass over that of untreated areas whereas blade MSP reduced it. Herbicide-related declines in trembling aspen biomass persisted or increased with time whereas white spruce response to herbicide varied with time and MSP. By accounting for inherent growth patterns, age shift calculations gave more balanced temporal depictions of planted white spruce response than effect size or percentage gain calculations. With barrel MSP, stand composition demonstrated a degree of mixedwood homeostasis whereas with blading, trembling aspen composition declined unilaterally from year 20 to 41.

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.

Mineralization rates and factors influencing snag decay in four North American boreal tree species

2012 ◽  
Vol 42 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Virginie A. Angers ◽  
P. Drapeau ◽  
Y. Bergeron
Keyword(s):  
Wood Density ◽  
Populus Tremuloides ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Jack Pine ◽  
Decay Rates ◽  
Balsam Fir ◽  
Time Since Death ◽  
Trembling Aspen ◽  
Boreal Species

The rate at which the wood of dead trees decays has numerous ecological implications. Decay rates of fallen tree boles have been extensively documented. However, decay rates of snags and the factors that influence decay in snags have received much less attention, especially in boreal species of eastern North America. In this study, mineralization rates (measured as wood density loss) were assessed in snags of four boreal species: trembling aspen (Populus tremuloides Michx.), balsam fir (Abies balsamea (L.) Mill.), jack pine (Pinus banksiana Lamb.), and black spruce (Picea mariana (Mill.) BSP). Wood density and variables potentially influencing decay rates (time since death, age, average radial growth, diameter at breast height, cerambycid larvae activity, and scolytid larvae activity) were measured on discs of 207 snags in northwestern Quebec, Canada. Mineralization rates varied significantly among species. Trembling aspen exhibited a more rapid rate of loss than conifers (k = 0.0274). Jack pine was the second most rapid species to lose wood density (k = 0.0152), followed by balsam fir (k = 0.0123). Black spruce was particularly resistant to mineralization (k = 0.0058), and its wood density was not significantly influenced by time elapsed since death for the time period sampled in this study. Time since death coupled with cerambycid larvae activity was associated with lower wood densities in trembling aspen, balsam fir, and jack pine, whereas slower growth was associated with a decreased mineralization rate in black spruce.

scholarly journals Role of Mixed-Species Stands in Attenuating the Vulnerability of Boreal Forests to Climate Change and Insect Epidemics

2021 ◽  
Vol 12 ◽  
Author(s):  
Raphaël D. Chavardès ◽  
Fabio Gennaretti ◽  
Pierre Grondin ◽  
Xavier Cavard ◽  
Hubert Morin ◽  
...  
Keyword(s):  
Climate Change ◽  
Populus Tremuloides ◽  
Tree Growth ◽  
Host Species ◽  
Boreal Forests ◽  
Linear Models ◽  
Black Spruce ◽  
Trembling Aspen ◽  
Mixed Stands ◽  
Species Mixture

We investigated whether stand species mixture can attenuate the vulnerability of eastern Canada’s boreal forests to climate change and insect epidemics. For this, we focused on two dominant boreal species, black spruce [Picea mariana (Mill.) BSP] and trembling aspen (Populus tremuloides Michx.), in stands dominated by black spruce or trembling aspen (“pure stands”), and mixed stands (M) composed of both species within a 36 km2 study area in the Nord-du-Québec region. For each species in each stand composition type, we tested climate-growth relations and assessed the impacts on growth by recorded insect epidemics of a black spruce defoliator, the spruce budworm (SBW) [Choristoneura fumiferana (Clem.)], and a trembling aspen defoliator, the forest tent caterpillar (FTC; Malacosoma disstria Hübn.). We implemented linear models in a Bayesian framework to explain baseline and long-term trends in tree growth for each species according to stand composition type and to differentiate the influences of climate and insect epidemics on tree growth. Overall, we found climate vulnerability was lower for black spruce in mixed stands than in pure stands, while trembling aspen was less sensitive to climate than spruce, and aspen did not present differences in responses based on stand mixture. We did not find any reduction of vulnerability for mixed stands to insect epidemics in the host species, but the non-host species in mixed stands could respond positively to epidemics affecting the host species, thus contributing to stabilize ecosystem-scale growth over time. Our findings partially support boreal forest management strategies including stand species mixture to foster forests that are resilient to climate change and insect epidemics.

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