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.

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

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.

Adapting forestry practices to address old-growth concerns in the Great Lakes–St.Lawrence forests of Ontario

2003 ◽  
Vol 79 (3) ◽  
pp. 613-620 ◽  
Author(s):  
Fred Pinto
Keyword(s):  
Great Lakes ◽  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Natural Disturbance ◽  
Red Pine ◽  
Forest Composition ◽  
White Birch ◽  
Site Factors ◽  
Old Growth ◽  
Old Growth Forests

The Great Lakes–St. Lawrence forest, particularly the eastern white (Pinus strobus L.) and red pine (P. resinosa Ait.) forests around Temagami and Sault Ste. Marie, was the centre of controversy regarding the treatment of old-growth forests in Ontario in the 1980s and 1990s. The controversy stemmed from changes in forest composition and structure occurring in the forest. For example, the Ontario public was concerned with the obvious reduction in numbers of large eastern white and red pine trees and their replacement with small, often poor quality, white birch (Betula papyrifera Marsh.), aspen (Populus tremuloides Michx.), and jack pine (Pinus banksiana Lamb.) trees. Over the past two decades, changes in legislation, forest planning and stand prescriptions have been made in Ontario and practices at the forest and stand levels have also changed significantly. The new practices are based on linking forest activities to a better understanding of ecological processes in the forest; in particular, linking harvest and regeneration activities to our current understanding of natural disturbances and plant adaptations. These practices attempt to match more closely the conditions found in forests with a heritage of natural disturbance and reproduction, i.e., old-growth forests. For example, stand-initiating disturbances result in some trees being killed, some being damaged, and some surviving. The new harvest practices consider tree adaptations and site factors when deciding whether a tree will be cut or not. This paper provides examples of how this ecosystem-based forestry is being applied in Ontario. Key words: old growth in Ontario, conservation of old growth, application of old growth conservation practices, stand practices for old growth, landscape practices for old growth

Effects of experimental harvesting on spider (Araneae) assemblages in boreal deciduous forests

2008 ◽  
Vol 140 (4) ◽  
pp. 437-452 ◽  
Author(s):  
Christopher M. Buddle ◽  
David P. Shorthouse
Keyword(s):  
Indicator Species ◽  
Boreal Forests ◽  
Large Scale ◽  
Wolf Spider ◽  
Natural Disturbance ◽  
Old Growth ◽  
Partial Cutting ◽  
Clear Cutting ◽  
Old Growth Forests ◽  
Geographic Separation

AbstractTwo large-scale forestry experiments, in Quebec (Sylviculture et aménagement forestiers écosystémique (SAFE)) and Alberta (Ecosystem Management by Emulating Natural Disturbance (EMEND)), were established in the late 1990s to test the effects of alternative silvicultural strategies (e.g., partial cutting) on biodiversity in northern boreal forests. We collected spiders in pitfall traps 2 years after the application of partial-cutting treatments in deciduous stands at EMEND and 6 years after similar treatments in deciduous stands at SAFE. Although we are aware of the challenges imposed by disparate locations and whole-scale experimental methods, our objective was to compare the effects of partial cutting on spider assemblages (diversity and community composition), and in doing so, to formulate a few general statements. Overall, 98 species (6107 individuals) were collected from Alberta and 86 species (3414 individuals) from Quebec. Of these, 44 species were common to both regions. Ordination and indicator-species analyses revealed a distinct effect of geographic separation: the spider assemblages in deciduous stands within the boreal plains ecoregion of Alberta and the boreal shield in Quebec were distinct. However, the effects of partial cutting on spider assemblages within each project were similar: removal of 25%–33% of trees shifted a characteristic old-growth fauna toward one more typical of clearcuts. Indicator-species analysis also revealed the dominance of wolf spider (Lycosidae) species in clearcuts within both experiments and we present evidence that clear-cutting homogenizes spider assemblages. Old-growth forests contain spider faunas that are easily disrupted by moderate partial cutting. In the face of intense harvesting practices, managing for the maintenance of biodiversity and conservation of spider faunas in northern forests will require retention of old-growth forests.

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.

Perspectives on development of definitions and values related to old-growth forests

2003 ◽  
Vol 11 (S1) ◽  
pp. S9-S22 ◽  
Author(s):  
Lee E Frelich ◽  
Peter B Reich
Keyword(s):  
Tree Height ◽  
Natural Disturbance ◽  
Primary Forest ◽  
Old Growth ◽  
Ecological Processes ◽  
Biological Resources ◽  
Stage Of Development ◽  
Second Growth ◽  
Old Growth Forests ◽  
Primary Forests

Old-growth forests are those that meet some threshold(s) determined by a scientific and political process. The main issue is what criteria to use to determine these thresholds; they must be practical enough to allow managers to delimit and manage old-growth stands in the field. People value forests with old and (or) big trees and primary forests that have a continuous heritage of natural disturbance and regeneration, even though the latter may include all stages of stand development and succession. We advocate uniting these two and using "primary forest", also called "natural heritage forest", as the criterion for delimiting old growth in regions where primary forest still exists. This criterion recognizes that the stage of development with big, old trees is part of a cycle of development, and it is necessary to have all the parts to continue to produce new examples of the older stages. The best available second-growth stands can be used in regions where primary forests are not available. Alternatively, threshold criteria for delimiting old growth can be based on tree size and age, but arbitrary criteria based on human size and age scales should be avoided in favour of criteria that specify stands dominated by trees relatively large and old for the species and site. Such criteria allow for old growth to occur across a variety of levels of site productivity, with trees of widely varying stature and with varying life-history characteristics, such as longevity, shade tolerance, and successional status. In any case, managers and scientists should work together to make sure that definitions work in the field but also include the ecological processes necessary to maintain the unique biological resources of old growth. The biological resources present in old growth may help to restore the second-growth landscape and allow reconstitution of forests in new places after global warming. Old-growth forests provide a baseline for comparison of effects of logging and natural disturbance, with respect to resilience to climatic change and disturbance, maintenance of species richness, and natural genetic structure of tree populations, which respond to different selective regimes in old growth and harvested forests. The species in old-growth remnants, their interactions and the resilience of the system after disturbance are as important or perhaps more so than the age and size of the trees at a given point in time. Key words: dwarf forest, Minnesota, old-growth processes, tree height.

Defining Canada's old-growth forests — problems and solutions

1994 ◽  
Vol 70 (6) ◽  
pp. 739-744 ◽  
Author(s):  
Luc C. Duchesne
Keyword(s):  
Landscape Ecology ◽  
Stand Age ◽  
Anthropogenic Influence ◽  
Annual Increment ◽  
Old Growth ◽  
Site Class ◽  
Old Growth Forests ◽  
Problems And Solutions ◽  
The Difference ◽  
Mean Annual Increment

Conceptual and working definitions of old-growth forests are proposed for Canada. Conceptually, old-growth forests are defined in terms of stand age, structure, species composition, anthropogenic influence, and landscape ecology. Working definitions based on stand age in relation to age of maximum mean annual increment and site class are formulated for Canada's inventoried timber-productive forests. The difference between stand age and the age of maximum mean annual increment is proposed as a measure of old-growthness. Recommendations are made for improving Canada's forest inventory database to help acquire ecological definitions of old-growth forests and monitor and maintain Canada's old-growth heritage. Key words: old-growth forests, stand composition, anthropogenic influence, biodiversity, landscape ecology

scholarly journals A note on the ecology and management of old-growth forests in the Montane Cordillera

2003 ◽  
Vol 79 (3) ◽  
pp. 441-454 ◽  
Author(s):  
André Arsenault
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Structural Characteristics ◽  
Coniferous Forest ◽  
Natural Disturbance ◽  
Climatic Conditions ◽  
Forest Types ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests

The Montane Cordillera ecozone that spans British Columbia's central and southern interior and a portion of southwestern Alberta contains the greatest variety of old-growth coniferous forest types in Canada. The diverse climates of this region, which include some of the driest, warmest, wettest, and coldest found in southern continental Canada, have directly contributed to the richness of old forest types. Associated with this range in climatic conditions are radically different natural disturbance regimes that have profoundly influenced the distribution, abundance, and structural characteristics of old-growth forests. Old forests tend to be more abundant and to contain more old-growth-dependent organisms in wetter climates. The high number of old-growth-dependent epiphytic lichens in old inland rainforests is a clear expression of this phenomenon. Conversely, old forests are much less abundant in dry landscapes. These forests, often dominated by Ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), have been subject to more frequent natural disturbances, and have been more profoundly influenced by human activities. Although fewer species appear to be dependent on old growth in dry forests, a number of them require certain old-growth structural attributes for their survival. A better understanding of the ecological characteristics of the old-growth forests of Canada's Montane Cordillera will assist in developing informed land-use decisions. Key words: old-growth forest, Montane Cordillera, natural disturbance, landscape ecology and management

Movements of wintering American marten (Martes americana): relative influences of prey activity and forest stand age

2011 ◽  
Vol 41 (11) ◽  
pp. 2202-2208 ◽  
Author(s):  
Charles Vigeant-Langlois ◽  
André Desrochers
Keyword(s):  
Foraging Behaviour ◽  
Forest Stand ◽  
Martes Americana ◽  
Movement Behavior ◽  
Stand Age ◽  
Habitat Requirements ◽  
American Marten ◽  
Old Growth ◽  
Fine Spatial Scale ◽  
Old Growth Forests

American marten (Martes americana (Turton, 1806)) was traditionally associated with old-growth forests, but recent evidence suggests that they are frequently found in younger forests as well. To better understand habitat requirements by this economically important furbearer, we investigated its fine-scale movement behavior in relation to local prey activity (tracks) and stand age. We georeferenced 34 marten tracks (57 km), associated prey tracks, and subnivean forays in a balsam fir forest of southern Québec, Canada. Marten movements were more tortuous in the presence of high numbers of prey tracks and near subnivean foraging sites. The latter relationships were stronger at a fine spatial scale (10 m movement steps) than at coarser scales (20 or 40 m movement steps). Marten movement tortuosity was unrelated to forest stand age after accounting for prey activity. These results support the hypothesis that the American marten does not hunt mainly in old-growth forests but appears to concentrate its foraging behaviour in areas with high prey activity.

Differences in lichen and bryophyte communities between old-growth and managed second-growth forests in the Swan Valley, Montana

1991 ◽  
Vol 69 (8) ◽  
pp. 1745-1755 ◽  
Author(s):  
Peter Lesica ◽  
Bruce McCune ◽  
Stephen V. Cooper ◽  
Won Shic Hong
Keyword(s):  
Woody Debris ◽  
Structural Diversity ◽  
Stand Age ◽  
Old Growth ◽  
Lobaria Pulmonaria ◽  
Β Diversity ◽  
Rotting Wood ◽  
Second Growth ◽  
Northwestern Montana ◽  
Old Growth Forests

Lichen and bryophyte communities differed between managed second-growth and unmanaged old-growth grand fir forests in northwestern Montana in all three strata examined: lower canopy, trunk, and ground. Old-growth forests had larger trees, greater structural diversity, greater volumes of coarse woody debris, fewer species of vascular plants, more species of trunk epiphytes, higher β diversity, and higher γ diversity than second-growth forests. Although pendent fruticose lichens were common in both stand age classes, species of Alectoria were more abundant in old growth, while second growth was dominated by Bryoria spp. Nitrogen-fixing foliose lichens were more common in all strata of old growth, and Lobaria pulmonaria, a common N-fixing species in old growth, was absent in second growth. Cladonia spp. were more numerous in second-growth forests. Nearly all species of leafy liverworts were more common in old growth and typically occurred on rotting wood. Many of these liverworts were absent from second growth. Our results suggest that many species of lichens and bryophytes find optimum habitat in old-growth forests and that these species will become less common as silvicultural practices continue to convert old growth to younger aged forests. Key words: bryophytes, diversity, forests, lichens, Montana, old growth.

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