Développement d’un outil de classification de la structure des peuplements et comparaison de deux territoires de la pessière à mousses du Québec

2003 ◽  
Vol 79 (2) ◽  
pp. 318-328 ◽  
Author(s):  
D Boucher ◽  
L De Grandpré ◽  
S Gauthier

Forest stand structure is an important element for biodiversity and, from a sustainable forest management perspective, uneven-sized stands should be managed in order to maintain the structural diversity over the landscape. The first objective of this study is to develop a statistical tool to characterize stand structure that can be used in forest management planning. The second objective is to classify the stand structure of two regions to illustrate a possible use for the tool. The statistical tool for characterizing stand structure has been developed from forest inventory data gathered by the ministère des Ressources naturelles du Québec, using discriminant analysis. The analysis makes it possible to classify the stands into three types of structure, even-sized, uneven-sized and inverse J-shaped, with an error rate estimated at only 7%. Proportions of different structure types in Quebec’s eastern black spruce forest region have been compared with those found in the western black spruce forest region. Nearly 90% of the western black spruce forest region is composed of pure black spruce stands, contrary to the eastern black spruce region, where there are more pure fir and mixed spruce-fir stands. Most of the western black spruce forest stands are even-sized (62%), while almost 70% of the eastern black spruce forest stands are uneven-sized or inverse J-shaped. Pure black spruce stands are more even-sized than pure fir stands, but regional differences are also found within pure black spruce stands. Our results show that it is possible to develop a robust tool that makes it possible to classify thousands of stands rapidly. Such tools are required if we want to consider stand structure for appropriate management prescriptions in the boreal forest. Key words: Even- and uneven-sized structure, fire regime, Picea mariana, Abies balsamea, boreal forest, structural diversity

2003 ◽  
Vol 11 (S1) ◽  
pp. S79-S98 ◽  
Author(s):  
Karen Harper ◽  
Catherine Boudreault ◽  
Louis DeGrandpré ◽  
Pierre Drapeau ◽  
Sylvie Gauthier ◽  
...  

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.


Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1199
Author(s):  
Louiza Moussaoui ◽  
Alain Leduc ◽  
Miguel Montoro Girona ◽  
Annie Claude Bélisle ◽  
Benoit Lafleur ◽  
...  

Over the past two decades, partial harvesting has been increasingly used in boreal forests as an alternative to clearcutting to promote irregular stand structures and maintain a balance between biodiversity preservation and continued timber production. However, relatively little is still known about the silvicultural potential of partial harvesting in Canada’s boreal forest, especially in areas prone to organic matter accumulation (paludification), and most prior research has focused on biodiversity responses. In this study, we assess the effects of partial harvesting on stand development (recruitment, growth, and mortality) ten years after harvesting in previously unmanaged black spruce stands and quantify its effectiveness in reducing the impacts on ecosystem structures. Our analyses revealed that pre-harvest stand structure and site characteristics, especially initial basal area, sapling density, tree diameter, and organic layer thickness (OLT) were major factors involved in stand development ten years following these partial harvesting treatments. Depending on pre-harvest structure and site characteristics, partial harvesting can result in either an increase in post-harvest tree recruitment and growth or a loss of stand volume because of standing tree mortality. To increase the chances of partial harvesting success in ensuring an increase in decennial stand yield after harvest in black spruce forest stands, sites prone to paludification (i.e., where OLT >17 cm) should be left unharvested. This study illustrates the importance of taking into account pre-existing structure and site characteristics in the selection of management strategies to maximize the potential of partial harvesting to achieve sustainable forest management in black spruce stands.


1990 ◽  
Vol 20 (9) ◽  
pp. 1471-1478 ◽  
Author(s):  
Chhun-Huor Ung

The mean ratio of height to diameter at breast height of dominant trees in a stand resulted in more accurate one-entry volume tables than general two-entry volume tables. These parametrical one-entry volume tables were established with the allometric model and Hummel's line. The values of their coefficients were estimated from stem analysis data of felled trees in black spruce stands at Lebel-sur-Quévillon. In the search for simple and effective methods to increase the reliability of standing stock estimation for managing a relatively homogeneous forest region, parametrical one-entry volume tables reduce the cost of estimating standing volume and increase the accuracy of volume estimation compared with general two-entry volume tables.


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 333 ◽  
Author(s):  
Stephanie A. Jean ◽  
Bradley D. Pinno ◽  
Scott E. Nielsen

Research Highlights: Black spruce (Picea mariana Mill.) and trembling aspen (Populus tremuloides Michx.) both regenerated vigorously after wildfire. However, pure semi-upland black spruce stands are at increasing risk of changing successional trajectories, due to greater aspen recruitment. Background and Objectives: Black spruce and aspen are found across the boreal forest with black spruce dominating lowlands and aspen being common in uplands. Both species are well adapted to wildfire with black spruce holding an aerial seedbank while aspen reproduce rapidly via root suckering. In the summer of 2016, the Horse River wildfire burned 589,617 hectares of northern Alberta’s boreal forest. Methods: We assessed early regeneration dynamics of both pure aspen and pure black spruce forests. For black spruce, 12 plots were established in both bog and semi-upland habitats to assess seedling regeneration and seedbed availability. For aspen, 12 plots were established in each of the low, moderate, and high burn severities, as well as 5 unburned plots. Results: Post-fire black spruce regeneration densities did not differ between bog and semi-upland habitats, but were positively correlated with forb cover and charred organic matter seedbeds. Aspen regeneration within pure black sprue stands was substantial, particularly in semi-upland habitats, indicating a potential shift in successional trajectory. Fire severity did not significantly affect aspen regeneration in pure aspen stands, but regeneration density in all severity types was >90,000 stems ha−1. Aspen regeneration densities were negatively related to post-fire forb and shrub cover, likely due to competition and cooler soil temperature.


2010 ◽  
Vol 114 (7) ◽  
pp. 1494-1503 ◽  
Author(s):  
K. Barrett ◽  
E.S. Kasischke ◽  
A.D. McGuire ◽  
M.R. Turetsky ◽  
E.S. Kane

1965 ◽  
Vol 43 (3) ◽  
pp. 393-404 ◽  
Author(s):  
J. Terasmae ◽  
R. J. Mott

Modern pollen content has been examined in 10 surface samples from the Nichicun Lake area, southwest of Schefferville, Quebec, and from three other localities in the same region. The pollen assemblages obtained reflect with fair reliability the regional characteristics of the northern boreal forest. Long-distance wind transport over several hundred miles is indicated by the presence of occasional ragweed and hardwood pollen grains from south of the boreal forest region. A morphological study of the black spruce pollen found indicates a rather wide range of variability, greater than that found in the pollen of black spruce south of this region.


2007 ◽  
Vol 245 (1-3) ◽  
pp. 137-147 ◽  
Author(s):  
Glen S. Brown ◽  
W. James Rettie ◽  
Ronald J. Brooks ◽  
Frank F. Mallory

2006 ◽  
Vol 86 (1) ◽  
pp. 1-9 ◽  
Author(s):  
N. Fenton ◽  
S. Légaré ◽  
Y. Bergeron ◽  
D. Paré

Globally, soil anoxia and water table rise play a role in the development of peatlands from forests. Cited causes have included a diversity of internal and external mechanisms, including Sphagnum and feather mosses, hardpan development, and peatland expansion. The objectives of this study were to examine water table depth in black spruce stands of the Clay Belt of Quebec and Ontario, and to associate changes with potential stand scale causal factors (primarily biological). A methodological issue, the link between oxygen zone and water table, was also addressed. Within stands less than 100 yr post-fire, oxygen zone and water table position were only loosely related, and no other potential factors were significantly correlated. Across a chronosequence of stands, while oxygen zone thickness in the soil profile was relatively constant, its position relative to the mineral soil changed, as it rose from the mineral soil into the forest floor. Forest floor thickness was the dominant explanatory factor in oxygen zone position, suggesting that in these forests other postulated mechanisms are less important. At the landscape level, the movement of the oxygen zone into the forest floor has important consequences for the long-term productivity of this intensively exploited forest region. Key words: Water table, black spruce, paludification, forest floor, Clay Belt, Sphagnum


2021 ◽  
Author(s):  
ZHONGHUA ZHAO ◽  
Gongqiao Zhang ◽  
Wenzhen Liu ◽  
Gangying Hui ◽  
Ganggang Zhang ◽  
...  

Abstract Background Improving the diversity and complexity of stand structure is the basis for maintaining and increasing forest ecosystem biodiversity. Measures of stand structural diversity is important for predicting stand growth and evaluating forest management activities. Based on the relationship of adjacent trees, we present a new method for the quantitative analysis of stand structure diversity that allows comparison of stand structural heterogeneity between different stands and forest types and to quantify the impact of forest management on structural diversity. Method: The diversity of structural unit types was defined and then we derive a new index of forest structural diversity () according to the additivity principle of Shannon-Weiner index. The effectiveness and sensitivity to management were verified by sixteen field survey samples in different locations and six different simulated management datasets based on Pinus koraiensis broad-leaved forest survey sample. Results (1) The mountain rainforest in Hainan had the highest \({{S}^{\text{'}}}_{D}\) value at 5.287, followed by broad-leaved Korean pine forest in Jiaohe (2), Jiaohe (1) and oak broadleaved mixed natural forest in Xiaolongshan (2), with values of 5.144, 5.014 and 5.006, respectively. The \({{S}^{\text{'}}}_{D}\) values of plantations and natural pure forest were lower. (2) Different thinning methods and intensities reduced \({{S}^{\text{'}}}_{D}\) compared with no treatment and magnitude of the with the differences were greater as thinning intensity increased. The \({{S}^{\text{'}}}_{D}\) value of thinning from above decreased more than thinning from below at the same thinning intensity. Conclusion The\({{S}^{\text{'}}}_{D}\) well describes differences in stand structural diversity of different forest types and allows comparison of stand structural heterogeneity. It is also sensitive to forest management activities and to quantify the impact of forest management on structural diversity. The application of this new index \({{S}^{\text{'}}}_{D}\) could greatly facilitate forest management and monitoring.


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