Old growth in the boreal forest: A dynamic perspective at the stand and landscape level

2003 ◽  
Vol 11 (S1) ◽  
pp. S99-S114 ◽  
Author(s):  
Daniel Kneeshaw ◽  
Sylvie Gauthier
Keyword(s):  
Boreal Forest ◽  
Old Growth ◽  
Dynamic Perspective ◽  
Landscape Level

scholarly journals Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances?

2007 ◽  
Vol 363 (1501) ◽  
pp. 2259-2268 ◽  
Author(s):  
Werner A Kurz ◽  
Graham Stinson ◽  
Greg Rampley
Keyword(s):  
Boreal Forest ◽  
Net Primary Production ◽  
Natural Disturbance ◽  
Climatic Changes ◽  
Forest Sector ◽  
Carbon Budget Model ◽  
C Stocks ◽  
Carbon Losses ◽  
Forest C ◽  
Landscape Level

To understand how boreal forest carbon (C) dynamics might respond to anticipated climatic changes, we must consider two important processes. First, projected climatic changes are expected to increase the frequency of fire and other natural disturbances that would change the forest age-class structure and reduce forest C stocks at the landscape level. Second, global change may result in increased net primary production (NPP). Could higher NPP offset anticipated C losses resulting from increased disturbances? We used the Carbon Budget Model of the Canadian Forest Sector to simulate rate changes in disturbance, growth and decomposition on a hypothetical boreal forest landscape and to explore the impacts of these changes on landscape-level forest C budgets. We found that significant increases in net ecosystem production (NEP) would be required to balance C losses from increased natural disturbance rates. Moreover, increases in NEP would have to be sustained over several decades and be widespread across the landscape. Increased NEP can only be realized when NPP is enhanced relative to heterotrophic respiration. This study indicates that boreal forest C stocks may decline as a result of climate change because it would be difficult for enhanced growth to offset C losses resulting from anticipated increases in disturbances.

Landscape-level variability in the age underestimation of understory black spruce in the northern boreal forest of Quebec

2005 ◽  
Vol 35 (3) ◽  
pp. 633-642 ◽  
Author(s):  
Marc-André Parisien ◽  
Luc Sirois ◽  
Sylvain Parent
Keyword(s):  
Boreal Forest ◽  
Mixed Models ◽  
Black Spruce ◽  
Ground Level ◽  
Simple Linear Regression ◽  
Linear Regression Models ◽  
Growth Rings ◽  
Age Correction ◽  
The Relationship ◽  
Landscape Level

This study examines the variability of the potential aging error for saplings (height ≤1.5 m) of black spruce (Picea mariana (Mill.) B.S.P.) in mature fire-dominated stands (n = 14 stands) of the northern boreal forest of northwestern Quebec. Age underestimation was determined by counting the number of underground bud scars of saplings. The magnitude and variability of age underestimation was compared within and among stands. The relationship between corrected ages (the sum of age underestimation and the number of growth rings at ground level) and ground-level ages was strongly linear and was therefore described with simple linear regression models. To evaluate landscape-level variability in this relationship, the regressions were compared among stands using mixed models. Despite high variability in age underestimation at the stand level, the relationship between corrected and ground-level age was highly significant (p < 0.0001) for all stands except one. However, there were many significant statistical differences between these regressions, indicating high landscape-level variability. The magnitude of age underestimation was found to be highly site specific (means of 7–26 years), the phenomenon being more marked and variable in older stands. Given high landscape-level variability, age underestimation of understory black spruce saplings in northern boreal stands must be documented for every sampled stand to apply a valid age correction in studies that involve multiple stands.

Beetle diversity in a matrix of old-growth boreal forest: influence of habitat heterogeneity at multiple scales

Ecography ◽  
2009 ◽  
Vol 32 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Philippe Janssen ◽  
Daniel Fortin ◽  
Christian Hébert
Keyword(s):  
Boreal Forest ◽  
Habitat Heterogeneity ◽  
Multiple Scales ◽  
Old Growth

Partial harvests in the boreal forest: response of the understory vegetation five years after harvest

2011 ◽  
Vol 87 (1) ◽  
pp. 86-98 ◽  
Author(s):  
Hervé Bescond ◽  
Nicole J Fenton ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Sustainable Forest Management ◽  
Forest Type ◽  
Mineral Soil ◽  
Community Change ◽  
Management Technique ◽  
Pioneer Species ◽  
Old Growth ◽  
Organic Layers ◽  
Canopy Opening

In the eastern boreal forest of Canada long fire cycles allow for a significant portion of stands to become old growth. Theseold-growth boreal forest stands are subjected to secondary disturbances that create uneven structure, which supports avariety of types of organisms. In order to maintain the proportion of stands with uneven structure on the landscape, partialcuts have been suggested as a management technique that could create or maintain these uneven structures. This studycompares the effects of partial and low-retention harvests and un-harvested control on understory plants in four sites fiveyears after harvest. The relative abundance of species was examined by a habitat group. While richness did not vary amongtreatments, increasing severity of harvest favoured pioneer species that prefer disturbed mineral soil and high light levels.Sites with thicker organic layers that were harvested in the winter were significantly less impacted by both partial and lowretentionharvest. Canopy opening alone had little impact in the three most northern sites. As old-growth black spruceforests are open by nature, this suggests that soil perturbation is a bigger driver of community change after harvest thanproportion of canopy removed for this forest type. Key words: Quebec, Picea mariana, harvest, variable retention, sustainable forest management, understory, structuralretention, vegetation

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 Old-Growth Southern Boreal Forest Stability and Response to a Stand-Replacing Wildfire

2017 ◽  
Vol 37 (4) ◽  
pp. 474-488
Author(s):  
Steven I. Apfelbaum ◽  
Alan Haney ◽  
Fugui Wang ◽  
John Burris ◽  
Jason Carlson
Keyword(s):  
Boreal Forest ◽  
Old Growth ◽  
Forest Stability

Structure, composition, and diversity of old-growth black spruce boreal forest of the Clay Belt region in Quebec and Ontario

2003 ◽  
Vol 11 (S1) ◽  
pp. S79-S98 ◽  
Author(s):  
Karen Harper ◽  
Catherine Boudreault ◽  
Louis DeGrandpré ◽  
Pierre Drapeau ◽  
Sylvie Gauthier ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Picea Mariana ◽  
Black Spruce ◽  
Small Scale ◽  
Structural Development ◽  
Spruce Forest ◽  
Forest Stands ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests

Old-growth black spruce (Picea mariana) boreal forest in the Clay Belt region of Ontario and Quebec is an open forest with a low canopy, quite different from what many consider to be "old growth". Here, we provide an overview of the characteristics of old-growth black spruce forest for three different site types on organic, clay, and coarse deposits. Our objectives were (1) to identify the extent of older forests; (2) to describe the structure, composition, and diversity in different age classes; and (3) to identify key processes in old-growth black spruce forest. We sampled canopy composition, deadwood abundance, understorey composition, and nonvascular plant species in 91 forest stands along a chronosequence that extended from 20 to more than 250 years after fire. We used a peak in tree basal area, which occurred at 100 years on clay and coarse sites and at 200 years on organic sites, as a process-based means of defining the start of old-growth forest. Old-growth forests are extensive in the Clay Belt, covering 30–50% of the forested landscape. Black spruce was dominant on all organic sites, and in all older stands. Although there were fewer understorey species and none exclusive to old-growth, these forests were structurally diverse and had greater abundance of Sphagnum, epiphytic lichens, and ericaceous species. Paludification, a process characteristic of old-growth forest stands on clay deposits in this region, causes decreases in tree and deadwood abundance. Old-growth black spruce forests, therefore, lack the large trees and snags that are characteristic of other old-growth forests. Small-scale disturbances such as spruce budworm and windthrow are common, creating numerous gaps. Landscape and stand level management strategies could minimize structural changes caused by harvesting, but unmanaged forest in all stages of development must be preserved in order to conserve all the attributes of old-growth black spruce forest. Key words: boreal forest, old growth, paludification, Picea mariana, structural development, succession.

Changes in relative abundance of snowshoe hares (Lepus americanus) across a 265-year gradient of boreal forest succession

2011 ◽  
Vol 89 (10) ◽  
pp. 908-920 ◽  
Author(s):  
James Hodson ◽  
Daniel Fortin ◽  
Louis Bélanger
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Forest Succession ◽  
Faecal Pellet ◽  
Canopy Gaps ◽  
Lepus Americanus ◽  
Stand Age ◽  
Suitable Habitat ◽  
Old Growth ◽  
Snowshoe Hares

Understory regeneration within canopy gaps in old-growth boreal forests may provide suitable habitat for wildlife typically associated with early-seral stages, leading to an increase in their abundance in late succession. We surveyed a chronosequence of postfire (17–265 years) and postharvest (3–63 years) stands in Canada’s eastern boreal forest to determine whether snowshoe hares ( Lepus americanus Erxleben, 1777) followed a bimodal abundance distribution with stand age that reflects changes in food and cover during postdisturbance succession. A strong peak in relative hare abundance occurred during the first 80 years of succession, with highest faecal pellet densities observed between 40 and 50 years after disturbance. Changes in hare abundance during this period were similar among fire- and clearcut-origin stands and closely tracked changes in lateral cover and vertical cover. Pellet density increased again in stands >180 years. Variation in hare abundance during late succession was partially mediated by gap dynamics, with highest pellet densities in stands occupied by an intermediate proportion of mortality-origin canopy gaps. Hares thus undergo rapid changes in abundance during early succession followed by a much longer period of subtle changes in density as stands develop old-growth structure. Shifting forest age-class distribution induced by forest management could therefore significantly alter regional spatiotemporal dynamics of snowshoe hares.

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