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

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

scholarly journals Gross value yield potential of coppice, high forest and model conversion of high forest to coppice on best sites

2011 ◽  
Vol 57 (No. 12) ◽  
pp. 536-546 ◽  
Author(s):  
M. Kneifl ◽  
J. Kadavý ◽  
R. Knott
Keyword(s):  
Czech Republic ◽  
The Other ◽  
Yield Potential ◽  
Fuel Wood ◽  
Annual Increment ◽  
Site Class ◽  
The Czech Republic ◽  
The Mean ◽  
Model Conversion ◽  
Mean Annual Increment

 Based on yield tables for oak high forest and oak coppice (both first site class) and using assortment tables and assortment prices in the Czech Republic in 2009, a set of variants of conversion of high forest to coppice was simulated. Average annual cut and average gross value of annual cut of such conversions were compared with those of well-established (in terms of the age structure balance) variants of coppice and high forest. Under the existing ratio of assortment prices, established coppice does not reach the gross value yield of high forest. No variant of simulated conversions was more financially profitable than the initial high forest. Furthermore, we found out that a +16.8% increase of the current fuel wood price would counterbalance the mean annual increment of gross value of the best coppice and the worst oak high forest variant. On the other hand, a +164.7% fuel wood price increase would be necessary to counterbalance the mean annual increment of gross value of the worst coppice and the best high forest variants.  

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.

scholarly journals A Loblolly Pine Seedling-Grade by Genotype Study

2002 ◽  
Vol 26 (3) ◽  
pp. 153-158 ◽  
Author(s):  
David B. South ◽  
James L. Rakestraw
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Annual Increment ◽  
Percentage Points ◽  
Sib Families ◽  
The Difference ◽  
Grade 3 ◽  
Pinus Taeda L ◽  
Mean Annual Increment ◽  
Percentage Point Difference

Abstract A loblolly pine (Pinus taeda L.) seedling grade study was established in January 1987 on a Coastal Plain site at Bellville, Georgia. The factorial study involved three seedling grades (Wakeley's Grade 1, 2, and 3) and three half-sib families (#5, 25, 56). Trees were measured at ages 8 and 13 yr. Both family and seedling grade affected survival, height, and diameter at age 8 yr. Survival among families varied by as much as 3 percentage points while there was a 10 percentage point difference between Grade 1 and Grade 2 seedlings. Only family was related to height and diameter at age 13. Volume gains from planting Grade 1 seedlings instead of Grade 3 seedlings varied by family but there were no significant interactions between family and seedling grade. Differences in height among families and among seedling grades decreased over time. At age 8, there was a 5.3 ft difference between the tallest and shortest family but by age 13, the difference declined to 3.7 ft.Overall, planting family 56 instead of family 25 resulted in an additional 645 ft3/ac by age 13. Planting Grade 1 seedlings instead of Grade 3 seedlings produced an additional 303 ft3/ac. Per acre volume differences among families were greater at age 13 than at age 8. In contrast, differences among seedling grades were about the same at age 8 and 13 yr. The overall mean annual increment (MAI) for this study was 207 ft3/ac/yr. In comparison, the MAI for Grade 1 seedlings of family 56 was 239 ft3/ac/yr. South. J. Appl. For. 26(3):153–158.

scholarly journals Deadwood Characteristics in Mature and Old-Growth Birch Stands and Their Implications for Carbon Storage

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 536 ◽  
Author(s):  
Silva Šēnhofa ◽  
Ieva Jaunslaviete ◽  
Guntars Šņepsts ◽  
Jurģis Jansons ◽  
Līga Liepa ◽  
...  
Keyword(s):  
Basal Area ◽  
High Volume ◽  
Stand Age ◽  
Old Growth ◽  
Stand Productivity ◽  
Stand Type ◽  
The Difference ◽  
Mineral Soils ◽  
Stand Height ◽  
Mature Stands

As one of the most abundant tree species in the hemiboreal zone, birch is important from both commercial and biodiversity perspectives. While old-growth deciduous stands are important for biodiversity conservation with an emphasis on deadwood availability, the role that deadwood in these stands plays in carbon sequestration remains unclear. We studied mature (71–110 years old) and old-growth (121–150 years old) birch stands on fertile mineral soils. The marginal mean deadwood volume was 43.5 ± 6.4 m3 ha−1 in all mature stands, 51.3 ± 7.1 m3 ha−1 in recently unmanaged mature stands, and 54.4 ± 4.4 m3 ha−1 in old-growth stands; the marginal mean deadwood carbon pool for each stand type was 5.4 ± 0.8 t·ha−1, 6.3 ± 0.9 t·ha−1, and 7.9 ± 0.6 t·ha−1, respectively. Deadwood volume was not related to stand productivity in terms of stand basal area, stand height, or stand age. The difference between mature and old-growth stands remained non-significant (p < 0.05). A high volume of deadwood was almost continuously present throughout the landscape in assessed unmanaged sites; moreover, 88% of sample plots in old-growth stands and 63% of sample plots in mature stands had a deadwood volume higher than 20 m3·ha−1. Old-growth stands had a slightly greater volume of large deadwood than unmanaged mature stands; in both, almost half of the deadwood was more than 30 cm in diameter and approximately one-fifth had a diameter greater than 40 cm. Both groups of stands had similar proportions of coniferous and deciduous deadwood and lying and standing deadwood. Old-growth stands had a higher volume of recently and weakly decayed wood, indicating increased dieback during recent years.

Bioenergy yield of Eucalyptus urophylla clones and its relationship with the mean annual increment of wood volume

2021 ◽  
Author(s):  
Bruna Isabele Pinheiro da Silva ◽  
Alyne Chaveiro Santos ◽  
Macksuel Fernandes da Silva ◽  
Mariana Dianese Alves de Moraes ◽  
Carlos Roberto Sette Jr
Keyword(s):  
Energy Density ◽  
Basic Density ◽  
Dry Mass ◽  
Energy Yield ◽  
Eucalyptus Urophylla ◽  
Annual Increment ◽  
Wood Volume ◽  
Wood Basic Density ◽  
The Difference ◽  
Mean Annual Increment

This study aimed to evaluate the energy yield and wood characteristics of Eucalyptus urophylla clones with different mean annual increment of wood volume (MAI). The clones presented MAIs of 39.2, 54.1 and 70.0 m3 ha-1 yr-1 in the field experiment at six years after planting when the trees were cut down to evaluate the wood basic density and higher heating values. The energy density, dry mass and energy yield were estimated. The MAI of E. urophylla clones influenced the wood basic density, dry mass, and energy yield, but did not influence the higher heating value and energy density. Clone 3 had the highest MAI, and also had higher energy yield and dry mass, but lower wood basic density. The difference between the most and the least productive clones was 242,648 MJ ha-1 yr-1. The results reinforce the importance of evaluating the wood quantity production (MAI) to select Eucalyptus clones for energy purposes.

scholarly journals L'état actuel des vieilles sapinières à Hylocomium à la forêt Montmorency de l'Université Laval

1969 ◽  
Vol 45 (1) ◽  
pp. 18-21
Author(s):  
Gilbert Paille
Keyword(s):  
Quality Index ◽  
Basal Area ◽  
Balsam Fir ◽  
Natural Mortality ◽  
Annual Increment ◽  
Site Class ◽  
Site Type ◽  
The Mean ◽  
Mean Annual Increment ◽  
Final Cutting

The present status of old balsam fir stands (Hylocomium-Oxalis site-type) has been studied on sites of second quality (index of 40 feet at 50 years) by means of 1/5-acre random sample plots. Comparisons with normal yield tables indicate that, between the age of 70 and 90 years, these stands show 1) too many stems per acre, mainly due to abundant ingrowth, 2) a constant average stand, d.b.h., 3) a loss of 30 sq.ft. per acre of basal area, and 4) a reduction of the mean annual increment in merchantable volume from 33 to 22 cu.ft. per acre.It is concluded that these site class II balsam fir stands are already mature, rapidly deteriorating, and failing to occupy the station fully. Consequently, they should be managed on rotations shorter than 70 years. Thinnings might be conducted 15 years before the final cutting to salvage otherwise heavy losses by natural mortality.

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.

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