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.

Influence of Fire on Long-Term Patterns of Forest Succession in Alaskan Boreal Forests

2000 ◽  
pp. 214-235 ◽  
Author(s):  
Eric S. Kasischke ◽  
Nancy H. F. French ◽  
Katherine P. O’Neill ◽  
Daniel D. Richter ◽  
Laura L. Bourgeau-Chavez ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Forest Succession

scholarly journals Resilience of the boreal forest in response to Holocene fire-frequency changes assessed by pollen diversity and population dynamics

2010 ◽  
Vol 19 (8) ◽  
pp. 1026 ◽  
Author(s):  
Christopher Carcaillet ◽  
Pierre J. H. Richard ◽  
Yves Bergeron ◽  
Bianca Fréchette ◽  
Adam A. Ali
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Frequency Control ◽  
Regional Scale ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Frequency Changes ◽  
Fire Intervals ◽  
In Fire

The hypothesis that changes in fire frequency control the long-term dynamics of boreal forests is tested on the basis of paleodata. Sites with different wildfire histories at the regional scale should exhibit different vegetation trajectories. Mean fire intervals and vegetation reconstructions are based respectively on sedimentary charcoal and pollen from two small lakes, one in the Mixedwood boreal forests and the second in the Coniferous boreal forests. The pollen-inferred vegetation exhibits different trajectories of boreal forest dynamics after afforestation, whereas mean fire intervals have no significant or a delayed impact on the pollen data, either in terms of diversity or trajectories. These boreal forests appear resilient to changes in fire regimes, although subtle modifications can be highlighted. Vegetation compositions have converged during the last 1200 years with the decrease in mean fire intervals, owing to an increasing abundance of boreal species at the southern site (Mixedwood), whereas changes are less pronounced at the northern site (Coniferous). Although wildfire is a natural property of boreal ecosystems, this study does not support the hypothesis that changes in mean fire intervals are the key process controlling long-term vegetation transformation. Fluctuations in mean fire intervals alone do not explain the historical and current distribution of vegetation, but they may have accelerated the climatic process of borealisation, likely resulting from orbital forcing.

Responses of boreal epiphytic bryophytes to different levels of partial canopy harvestThis paper is one of a selection of papers published as part of the special Schofield Gedenkschrift.

Botany ◽  
2010 ◽  
Vol 88 (4) ◽  
pp. 315-328 ◽  
Author(s):  
Richard T. Caners ◽  
S. Ellen Macdonald ◽  
René J. Belland
Keyword(s):  
Populus Tremuloides ◽  
Boreal Forests ◽  
Management Practices ◽  
Forest Harvesting ◽  
Forest Growth ◽  
Hylocomium Splendens ◽  
Interspecific Associations ◽  
Tree Retention ◽  
Growing Conditions ◽  
Different Levels

Epiphytic mosses and liverworts contribute substantially to the bryophyte diversity of circumpolar boreal forests but are susceptible to altered growing conditions after forest harvesting. Management practices that retain some trees after harvest may enhance epiphyte survival; however, the effectiveness of this emerging method needs to be assessed. We examined the survival, composition, and nearest neighbour relationships of epiphytic bryophytes on trembling aspen ( Populus tremuloides Michx.) across a range (10%–100%) of dispersed green-tree retention 5 years after harvest in boreal mixed-wood forest. Growth of the forest floor moss Hylocomium splendens (Hedw.) Schimp. in B.S.G. was used as an indicator of changes in moisture availability for epiphytes following harvesting. Epiphyte richness and abundance increased with canopy retention and were positively correlated with local abundance of coniferous trees. Positive associations among neighbouring species in intact forest demonstrated that interspecies relationships form naturally. However, there was a shift in species composition after harvesting and fewer interspecific associations with declining retention. These trends were accompanied by reduced Hylocomium splendens growth, which implies that moisture may be an important driver of epiphyte response. Although different levels of canopy retention were similarly capable of maintaining some epiphytes, the loss of species associated with intact forest will require consideration of alternative management practices for their conservation.

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.

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.

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.

Seed and bud legacies interact with varying fire regimes to drive long-term dynamics of boreal forest communities

2005 ◽  
Vol 35 (11) ◽  
pp. 2765-2773 ◽  
Author(s):  
Eliot JB McIntire ◽  
Robin Duchesneau ◽  
JP (Hamish) Kimmins
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Populus Tremuloides ◽  
Natural Regeneration ◽  
Forest Succession ◽  
Lodgepole Pine ◽  
Forest Community ◽  
Trembling Aspen ◽  
High Severity

Sustainable forest management that employs the emulation of natural disturbance paradigm develops plans based on disturbance-driven forest succession. However, most research on forest succession has focused primarily on postdisturbance species change, often ignoring predisturbance legacies. We used the FORECAST ecosystem management model and a newly created natural regeneration submodel to examine the interaction of fire severity, fire frequency, and natural regeneration to produce multicycle dynamics of white spruce (Picea glauca (Moench) Voss), lodgepole pine (Pinus contorta Dougl. ex Loud.), and trembling aspen (Populus tremuloides Michx.) in a western Canadian boreal forest. We simulated 19 different scenarios in a factorial disturbance experiment of three severities and six frequencies and a no-disturbance scenario. Our simulations resulted in a wide diversity of boreal forest community types, including trembling aspen dominated mixedwoods with high-frequency (75 year), high-severity (100% mortality) fires, and nearly pure lodgepole pine stands at midfrequency (100–125 year) and high-severity fires. With the unvarying disturbance regimes we used, a variety of different but recurring temporal patterns emerged. We show that the loss of seed source legacies reinforces the disturbance-driven species dominance, demonstrating community inertia. This study provides a long-term perspective to boreal forest management that demonstrates the role of disturbance and legacies in long-term dynamics.

scholarly journals Forest growth trends in Canada

2019 ◽  
Vol 95 (03) ◽  
pp. 183-195 ◽  
Author(s):  
Craig Loehle ◽  
Kevin A. Solarik
Keyword(s):  
Populus Tremuloides ◽  
Growth Models ◽  
Abiotic Factors ◽  
N Deposition ◽  
Forest Growth ◽  
Past Century ◽  
Multiple Sources ◽  
Eastern Canada ◽  
Growth Trends

Reports have identified changes in abiotic factors that potentially affect forest growth. A synthesis of studies of thesechanges in Canada over the past century was undertaken to evaluate how these factors may be influencing forest growth.Reviewed papers used multiple sources of data including long-term inventory plots, tree-ring reconstructions, historicalgeographic data, and forest growth models. The synthesis showed that several positive growth trends were found inBritish Columbia and eastern Canada, while results from the western interior of Canada were mixed. Trembling aspen(Populus tremuloides Michx.) dieback has been noted due to severe and prolonged drought events, with growth reduc-tions and mortality also documented for conifers in the western interior. Studies have also found slow forest expansionin many areas and at the northern tree-line. Overall, authors attributed positive forest growth trends to rising CO2 con-centrations, N deposition, increased precipitation, and increased temperature. Growth declines were generally attributedto a combination of increased temperatures and reduced precipitation. Studies also differed due to time periods consid-ered and how age effects were corrected. Methodological issues were identified that led to contradictory results betweensome studies. These issues need further study.

Enhanced Seasonal Exchange of CO2 by Northern Ecosystems Since 1960

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1085-1089 ◽  
Author(s):  
H. D. Graven ◽  
R. F. Keeling ◽  
S. C. Piper ◽  
P. K. Patra ◽  
B. B. Stephens ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Atmospheric Carbon Dioxide ◽  
Ecosystem Models ◽  
The North ◽  
Ecological Changes ◽  
Term Change ◽  
Major Shift ◽  
Underlying Mechanisms ◽  
Global Carbon

Seasonal variations of atmospheric carbon dioxide (CO2) in the Northern Hemisphere have increased since the 1950s, but sparse observations have prevented a clear assessment of the patterns of long-term change and the underlying mechanisms. We compare recent aircraft-based observations of CO2 above the North Pacific and Arctic Oceans to earlier data from 1958 to 1961 and find that the seasonal amplitude at altitudes of 3 to 6 km increased by 50% for 45° to 90°N but by less than 25% for 10° to 45°N. An increase of 30 to 60% in the seasonal exchange of CO2 by northern extratropical land ecosystems, focused on boreal forests, is implicated, substantially more than simulated by current land ecosystem models. The observations appear to signal large ecological changes in northern forests and a major shift in the global carbon cycle.

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