Comparisons between wildfire and forest harvesting and their implications in forest management

2001 ◽  
Vol 9 (4) ◽  
pp. 223-260 ◽  
Author(s):  
D J McRae ◽  
L C Duchesne ◽  
B Freedman ◽  
T J Lynham ◽  
S Woodley
Keyword(s):  
Forest Management ◽  
Timber Harvesting ◽  
Forest Harvesting ◽  
Slope Aspect ◽  
Stand Age ◽  
Small Subset ◽  
Eastern Canada ◽  
Old Growth ◽  
Large Numbers ◽  
Old Growth Forests

Emulation silviculture is the use of silvicultural techniques that try to imitate natural disturbances such as wildfire. Emulation silviculture is becoming increasingly popular in Canada because it may help circumvent the political and environmental difficulties associated with intensive forest harvesting practices. In this review we summarize empirical evidence that illustrates disparities between forest harvesting and wildfire. As a rule, harvesting and wildfire affect biodiversity in different ways, which vary a great deal among ecosystem types, harvesting practices, and scale of disturbance. The scales of disturbance are different in that patch sizes created by logging are a small subset of the range of those of wildfire. In particular, typical forestry does not result in the large numbers of small disturbances and the small number of extremely large disturbances created by wildfires. Moreover, the frequency of timber harvesting is generally different from typical fire return intervals. The latter varies widely, with stand-replacing fires occurring in the range of 20 to 500 years in Canada. In contrast, harvest frequencies are dictated primarily by the rotational age at merchantable size, which typically ranges from 40 to 100 years. Forest harvesting does not maintain the natural stand-age distributions associated with wildfire in many regions, especially in the oldest age classes. The occurrence of fire on the landscape is largely a function of stand age and flammability, slope, aspect, valley orientation, and the location of a timely ignition event. These factors result in a complex mosaic of stand types and ages on the landscape. Timber harvesting does not generally emulate these ecological influences. The shape of cut blocks does not follow the general ellipse pattern of wind driven fires, nor do harvested stands have the ragged edges and unburned patches typically found in stand-replacing fires. Wildfire also leaves large numbers of snags and abundant coarse woody debris, while some types of harvesting typically leave few standing trees and not much large debris. Successional pathways following logging and fire often differ. Harvesting tends to favor angiosperm trees and results in less dominance by conifers. Also, understory species richness and cover do not always recover to the pre-harvest condition during the rotation periods used in typical logging, especially in eastern Canada and in old-growth forests. As well, animal species that depend on conifers or old-growth forests are affected negatively by forest harvesting in ways that may not occur after wildfire. The road networks developed for timber extraction cause erosion, reduce the areas available for reforestation, fragment the landscape for some species and ecological functions, and allow easier access by humans, whereas there is no such equivalency in a fire-disturbed forest. Key words: silviculture, forest management, clearcutting, forest conservation, wildfire, biodiversity.

Is regulated even-aged management the right strategy for the Canadian boreal forest?

2004 ◽  
Vol 80 (4) ◽  
pp. 458-462 ◽  
Author(s):  
Yves Bergeron
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Biological Diversity ◽  
Fire Regime ◽  
Age Distribution ◽  
Fire Frequency ◽  
Stand Age ◽  
Old Growth ◽  
Old Growth Forests ◽  
Canadian Boreal Forest

Over the past decade, there has been an increasing interest in the development of forest management approaches that are based on an understanding of historical natural disturbance dynamics. The rationale for such an approach is that management to favour landscape compositions and stand structures similar to those of natural ecosystems should also maintain biological diversity and essential ecological functions. In fire-dominated landscapes, this approach is possible only if current and future fire frequencies are sufficiently low, in comparison to pre-industrial fire frequency, that we can substitute fire with forest management. I address this question by comparing current and future fire frequency to historical reconstruction of fire frequency from studies in the Canadian boreal forest. Current and simulated future fire frequencies using 2× and 3×CO2 scenarios are lower than the historical fire frequency for most sites, suggesting that forest management could potentially be used to recreate the forest age structure of fire-controlled pre-industrial landscapes. Current even-aged management, however, tends to reduce forest variability: for example, fully regulated, even-aged management will tend to truncate the natural forest stand age distribution and eliminate overmature and old-growth forests from the landscape. The development of silvicultural techniques that maintain a spectrum of forest compositions and structures at different scales in the landscape is one avenue to maintain this variability. Key words: boreal forest, even aged management, fire regime, old-growth forests, climate change, partial cutting

Saproxylic insect assemblages in Canadian forests: diversity, ecology, and conservation

2008 ◽  
Vol 140 (4) ◽  
pp. 453-474 ◽  
Author(s):  
David W. Langor ◽  
H.E. James Hammond ◽  
John R. Spence ◽  
Joshua Jacobs ◽  
Tyler P. Cobb
Keyword(s):  
Forest Management ◽  
Boreal Forests ◽  
Dead Wood ◽  
Sustainable Forest Management ◽  
Forest Harvesting ◽  
Stand Age ◽  
Managed Forests ◽  
Saproxylic Insects ◽  
Associated Species ◽  
Experimental Burns

AbstractSaproxylic insect assemblages inhabiting dead wood in Canadian forests are highly diverse and variable but quite poorly understood. Adequate assessment of these assemblages poses significant challenges with respect to sampling, taxonomy, and analysis. Their assessment is nonetheless critical to attaining the broad goals of sustainable forest management because such species are disproportionately threatened elsewhere by the reductions in dead wood generally associated with commercial exploitation of northern forests. The composition of the saproxylic fauna is influenced by many factors, including tree species, degree of decay, stand age, and cause of tree death. Wildfire and forest harvesting have differential impacts on saproxylic insect assemblages and on their recovery in postdisturbance stands. Exploration of saproxylic insect responses to variable retention harvesting and experimental burns is contributing to the development of prescriptions for conserving saproxylic insects in boreal forests. Understanding of processes that determine diversity patterns and responses of saproxylic insects would benefit from increased attention to natural history. Such work should aim to provide a habitat-classification system for dead wood to better identify habitats (and associated species) at risk as a result of forest management. This tool could also be used to improve strategies to better maintain saproxylic organisms and their central nutrient-cycling functions in managed forests.

scholarly journals Forest management has reduced the structural diversity of residual boreal old-growth forest landscapes in Eastern Canada

2020 ◽  
Vol 458 ◽  
pp. 117765 ◽  
Author(s):  
Maxence Martin ◽  
Yan Boucher ◽  
Nicole J. Fenton ◽  
Philippe Marchand ◽  
Hubert Morin
Keyword(s):  
Forest Management ◽  
Structural Diversity ◽  
Eastern Canada ◽  
Old Growth ◽  
Old Growth Forest

Forestry and Black-tailed Deer: Conflicts, Crises, or Cooperation

1985 ◽  
Vol 61 (2) ◽  
pp. 180-184 ◽  
Author(s):  
F. W. Bunnell
Keyword(s):  
Timber Harvesting ◽  
Old Growth ◽  
Winter Habitat ◽  
Fine Grained ◽  
Functional Relationships ◽  
Forestry Practices ◽  
Old Growth Forests ◽  
Research Findings ◽  
Growth Features ◽  
Initial Research

Prior to 1970, research on the relationships between black-tailed deer and forestry practices was largely restricted to areas of low snowfall. Findings suggested that deer populations responded positively to the increased forage generated by timber harvesting practices, and forestry was assumed to be beneficial to black-tailed deer. The first research in areas of high snowfall obtained contrary results; in fact, old-growth forests were found to be valuable habitats for deer. Subsequent research documented that there were four major reasons why old-growth forests provided ideal winter habitat: reduced costs of locomotion in snow, lower rates of food burial, provision of arboreal lichen, and a more heterogeneous, fine-grained environment. Initial research findings encouraged harvesting guidelines that temporarily reserved tracts of old growth as winter ranges. The guidelines were enacted while research, would eventually suggest alternative approaches, continued to examine functional relationships. Current solutions to the conflict include intensive, specific silvicultural practices to mimic old-growth features in managed stands. Review of the conflict provides several lessons of broader applicability.

Carbon storage in Lake States aspen ecosystems

1992 ◽  
Vol 22 (8) ◽  
pp. 1107-1110 ◽  
Author(s):  
D.H. Alban ◽  
D.A. Perala
Keyword(s):  
Soil Carbon ◽  
Carbon Storage ◽  
Timber Harvesting ◽  
Old Growth ◽  
Standing Biomass ◽  
Ecosystem Carbon ◽  
Old Growth Forests ◽  
Lake States

Total ecosystem carbon in the soil and vegetation was measured for a range of aspen (Populustremuloides Michx.) ecosystems, including a chronosequence on the same soil ranging in age from 0 to 80 years. Soil carbon stayed relatively constant throughout the stand's life and was not affected by timber harvesting. Changes in ecosystem carbon closely paralleled the changes in standing biomass. Aspen grown on 40-year rotations on good soils will sequester several times as much carbon per year as old-growth forests.

Spatial patterns, trends, and the potential long-term impacts of tree harvesting on lake calcium levels in the Muskoka River Watershed, Ontario, Canada

2016 ◽  
Vol 73 (3) ◽  
pp. 382-393 ◽  
Author(s):  
Carolyn R. Reid ◽  
Shaun A. Watmough
Keyword(s):  
Forest Management ◽  
Surface Waters ◽  
Aquatic Ecosystems ◽  
Timber Harvesting ◽  
Eastern Canada ◽  
River Watershed ◽  
Management Plans ◽  
The Mean ◽  
Ca Depletion

The issue of calcium (Ca) decline in surface waters of eastern Canada is an emerging concern that may be made worse by timber harvesting. In the Muskoka River Watershed (MRW) in Ontario, the mean lake Ca concentration in 104 lakes decreased by 30% since the 1980s, with the rate of decrease slowing over time consistent with changes in lake sulfate (SO4) as the region recovers from acid deposition. Recent data suggested that smaller lakes, at higher elevation, in smaller catchments with higher runoff that are minimally impacted by the influence of roads and agriculture are associated with lower Ca concentrations and thus are the lakes most at risk of amplified Ca depletion. Using proposed annual allowable harvest cuts from 10-year forest management plans, 38% of 364 lakes assessed in the MRW will fall below a reported critical 1 mg·L–1 Ca threshold compared with just 8% in the absence of future harvesting. It is concluded that Ca decline poses a serious threat to aquatic ecosystems and should be taken into consideration in future forest management plans.

Greater risk of physical damage caused by debris fall to understory plants and tree seedlings in old-growth forests than in young forests

2013 ◽  
Vol 43 (12) ◽  
pp. 1203-1206 ◽  
Author(s):  
Andrew J. Larson
Keyword(s):  
Woody Debris ◽  
Canopy Structure ◽  
Snow Accumulation ◽  
Stand Age ◽  
Tree Seedlings ◽  
Physical Damage ◽  
Old Growth ◽  
Understory Plants ◽  
Old Growth Forests ◽  
Young Forests

Falling canopy debris causes injury and mortality of tree seedlings and understory plants in a wide variety of forests. Canopy structure and dynamics differ between young and old-growth forests: old forests are taller and have more aboveground biomass and greater annual mortality of bole biomass. I predicted that risk of damage caused by debris fall in the understory is greater in old-growth forests than in young forests. I tested this prediction by tracking for 1 year the fates of artificial seedlings placed in young (stand age 31 to 61 years) and old-growth (stand age circa 500 years) Pseudotsuga–Tsuga forests. The risk of physical damage caused by debris fall in old-growth forests was significantly greater than in young forests (P = 0.001). Seedling models were damaged by falling debris at a rate of 4.4%·year−1 and 0.8%·year−1 in old-growth and young forests, respectively. More seedling models were damaged by fallen coarse woody debris in old-growth forests than in young forests, although this trend was not significant (P = 0.134). Approximately 25% of seedling models in both young and old-growth forests were damaged by something other than fallen canopy debris, most likely snow accumulation.

Are the old-growth forests of the Clay Belt part of a fire-regulated mosaic?

2005 ◽  
Vol 35 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Dominic Cyr ◽  
Yves Bergeron ◽  
Sylvie Gauthier ◽  
Alayn C Larouche
Keyword(s):  
Fire Hazard ◽  
Natural Disturbance ◽  
Great Variability ◽  
Stand Age ◽  
Old Growth ◽  
Fire Cycle ◽  
Old Growth Forests ◽  
Ring Method ◽  
Forest Mosaic ◽  
Macroscopic Charcoal

Old-growth forests make up a substantial proportion of the forest mosaic in the Clay Belt region of Ontario and Quebec, Canada, despite fire cycles that are presumed to be relatively short. Two hypotheses have been suggested as explanations for this phenomenon: (1) the old-growth forests in question are located on sites that are protected from fire or (2) the fire hazard is just as great there as elsewhere, and that part of the mosaic is simply the tail of the distribution, having been spared from fire merely by chance. The tree-ring method has proven inadequate as a means of determining the date of the most recent fire in these old-growth forests, as the time that has elapsed since that date probably exceeds the age of the oldest trees. Accordingly, a paleoecological study was conducted with a view to determining the date of the last fire in these forests. Charcoal horizons were located and radiocarbon dated in six old-growth forests. The possibility that these forests have never burned at all is ruled out by the fact that macroscopic charcoal fragments were found at all sites. The proximity of potential firebreaks has a significant influence in the survival model, suggesting fire-cycle heterogeneity throughout the landscape. However, the proportion of old-growth forests observed is in agreement with what would be expected assuming that fire hazard is independent of stand age. Old-growth stands could thus be incorporated into natural disturbance based management, although the great variability of the intervals between catastrophic disturbances should be carefully considered.

Long-term recovery of vegetation communities after harvesting in the coastal temperate rainforests of northern British Columbia

2008 ◽  
Vol 38 (12) ◽  
pp. 3098-3111 ◽  
Author(s):  
Allen Banner ◽  
Philip LePage
Keyword(s):  
British Columbia ◽  
Species Richness ◽  
Thuja Plicata ◽  
Stand Age ◽  
Terrestrial Vegetation ◽  
Old Growth ◽  
Second Growth ◽  
Old Growth Forests ◽  
Young Forests ◽  
Logging Disturbance

We sampled second-growth forests ranging in age from 28 to 98 years and compared them with old-growth forests to quantify rates of terrestrial vegetation recovery following harvesting on the northcentral coast of British Columbia. Species richness approximately doubles, while Simpson’s index of diversity increases from 0.81 to 0.91 from young to old forests. Nonmetric multidimensional scaling ordinations showed differentiation, with some overlap, of old-growth and second-growth forests and a fairly strong correlation of stand age with plot scores, driven by plant species presence and cover. Vegetation succession following logging disturbance is driven primarily by predisturbance species composition; most species found in the young forests are present in old forests and the higher species richness typical of old growth is largely due to the establishment of additional cryptogam and herb species of low cover and constancy. Significantly higher cover of shrub, herb, and bryophyte species differentiates old forests from second-growth forests. Forests 41–100 years old average 63%–73% similarity (depending on site type) to old-growth forests based on species presence–absence and 53%–58% similarity based on species cover. The scarcity of western redcedar ( Thuja plicata Donn ex D. Don) in second-growth stands is of particular concern because of the high ecological, cultural, and economic importance of this tree species.

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