scholarly journals Broad-Scale Classification and Mapping of Tree Size and Density Attributes in Productive Old-Growth Forests in Southeast Alaska's Tongass National Forest

2008 ◽  
Vol 23 (2) ◽  
pp. 106-112 ◽  
Author(s):  
John P. Caouette ◽  
Eugene J. DeGayner

Abstract The forest classification and mapping system currently used in managing the Tongass National Forest (NF) is based largely on an economic forest measure, net board foot volume per acre. Although useful for timber economic modeling, this forest measure poorly differentiates old-growth forest types in a way that is meaningful to ecological and social concerns. In 2005, we published an article presenting a proposed tree size and tree density mapping model for the Tongass NF. We claimed the model would provide better information on the structural patterns in old-growth forests than did the current mapping models based on net board foot volume per acre. We also stated that further testing of our proposed model is required before it can be fully integrated into forest management plans and landscape analysis. In this article, we used independent field data to evaluate our proposed tree size and density model and better define its accuracy. Results showed differences among mapping classes similar to differences observed in the development stages of the model. Results also showed mapping accuracy estimates between 60 and 80%. We used the model in a forest management application by comparing the representation of old-growth forest types within a landscape to the representation within a management-defined subset of that landscape.

2007 ◽  
Vol 139 (1) ◽  
pp. 118-130 ◽  
Author(s):  
Rebecca M. Zeran ◽  
Robert S. Anderson ◽  
Terry A. Wheeler

AbstractFungivorous Coleoptera were sampled from old-growth and managed (selectively logged in 1999) hemlock–hardwood forests in southeastern Ontario to examine the effect of small-scale forest management on fungivore diversity in forest fragments. Sampling using flight-intercept traps and trunk-window traps for 22 weeks in 2003 yielded 11 888 beetles representing 73 species in 11 target families (Anthribidae, Cerylonidae, Endomychidae, Erotylidae, Leiodidae, Mycetophagidae, Scaphidiidae, Sphindidae, Tenebrionidae, Trogossitidae, and Zopheridae). The leiodid subfamily Leiodinae was the dominant taxon (10 386 individuals, 38 species). While old-growth stands had no recent logging and had higher volumes of coarse woody debris, species diversity and composition of fungivorous Coleoptera were similar between forest types, suggesting that the stand differences measured (recent logging history, volume of coarse woody debris) did not have a significant effect on beetle diversity in this study. Indicator species analysis showed that Triplax macra LeConte (Erotylidae) was strongly associated with old-growth stands, while Anisotoma blanchardi (Horn), Anogdus obsoletus (Melsheimer), Agathidium sp. 1 (Leiodidae), and Mycetina perpulchra (Newman) (Endomychidae) were associated with managed stands. The lack of difference observed between stand types may be related to the small size of the forest fragments or the relatively small scale of the disturbance.


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 252 ◽  
Author(s):  
Maxence Martin ◽  
Cornélia Krause ◽  
Nicole J. Fenton ◽  
Hubert Morin

Research Highlights: Radial growth patterns of trees growing in old-growth boreal forests in eastern Canada can be grouped into a small number of simple patterns that are specific to different old-growth forest types or successional stages. Background and Objectives: Identifying the main radial growth trends in old-growth forests could help to develop silvicultural treatments that mimic the complex dynamics of old-growth forests. Therefore, this study aimed to identify the main radial growth patterns and determine how their frequencies change during forest succession in old-growth forests, focusing on boreal landscapes in eastern Canada. Materials and Methods: We used dendrochronological data sampled from 21 old-growth stands in the province of Quebec, Canada. Tree-ring chronologies were simplified into chronologies of equal length to retain only primary growth trends. We used k-means clustering to identify individual growth patterns and the difference in growth-pattern frequency within the studied stands. We then used non-parametric analyses of variance to compare tree or stand characteristics among the clusters. Results: We identified six different growth patterns corresponding to four old-growth forest types, from stands at the canopy breakup stage to true old-growth stands (i.e., when all the pioneer cohort had disappeared). Secondary disturbances of low or moderate severity drove these growth patterns. Overall, the growth patterns were relatively simple and could be generally separated into two main phases (e.g., a phase of limited radial increment size due to juvenile suppression and a phase of increased radial increment size following a growth release). Conclusions: The complexity of old-growth forest dynamics was observed mainly at the stand level, not at the tree level. The growth patterns observed in true old-growth forests were similar to those observed following partial or stem-selection cuts in boreal stands; thus, these silvicultural treatments may be effective in mimicking old-growth dynamics.


2003 ◽  
Vol 79 (3) ◽  
pp. 441-454 ◽  
Author(s):  
André Arsenault

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


2003 ◽  
Vol 11 (S1) ◽  
pp. S1-S7 ◽  
Author(s):  
A Mosseler ◽  
I Thompson ◽  
B A Pendrel

In response to a broad public concern about the rapidly diminishing area of old-growth forests and their intrinsic biological value, the Canadian Forest Service organized a national symposium in 2001 to discuss the old-growth issue from a science perspective. The objectives were: (i) to bring together Canadian expertise on old-growth forests, (ii) to define old growth within the main forest regions of Canada, (iii) to understand its biological complexities and ecological roles, and (iv) to discuss management and restoration experiences and options. Some forest regions of Canada still contain significant old-growth forest (e.g., some boreal forest regions), although other regions contain very little primary, relatively undisturbed, older forest (e.g., eastern temperate-zone forest regions). One of the difficulties in managing and conserving old-growth forests is defining them in a scientifically meaningful, yet operational and policy-relevant manner. This difficulty may be overcome by developing an index of "old-growthness" (Spies and Franklin 1988) related to specific forest regions or forest types. Such an old-growth index would allow for the inclusion of specific attributes, composition, functions, and processes seen as relevant to different ecological regions or specific forest types and could serve as a basis for prioritizing local or regional conservation and management activities. Thus, such an index approach has worldwide applicability. Traditionally, old-growth forests have been valued primarily as habitat for forest-dependent, specifically old-growth-dependent, wildlife. Recent results from research on old-growth forests in eastern Canada suggest that as tree populations age they tend to increase in genetic diversity and reproductive fitness, suggesting that old-growth forests may serve as natural reservoirs of genetic diversity and reproductive fitness for the constituent tree species. This has important implications for the dispersal and adaptation of trees across increasingly fragmented forest landscapes subject to the anticipated rapid climatic changes and the introduction of new pest and disease problems. Old-growth conservation goes well beyond the more traditional areas of watershed (including water quality) and habitat protection and includes emerging issues such as the conservation of genetic resources and carbon sequestration. It is very much a cross-sectoral issue with many interdisciplinary linkages. Therefore, conservation and protection of old-growth forests should be of wide general interest to the forest sector. Key words: biodiversity conservation, Canada's forests, genetic diversity, late-successional temperate forests, old-growth index, reproductive fitness.


2021 ◽  
Vol 4 ◽  
Author(s):  
Maxence Martin ◽  
Pierre Grondin ◽  
Marie-Claude Lambert ◽  
Yves Bergeron ◽  
Hubert Morin

Large primary forest residuals can still be found in boreal landscapes. Their areas are however shrinking rapidly due to anthropogenic activities, in particular industrial-scale forestry. The impacts of logging activities on primary boreal forests may also strongly differ from those of wildfires, the dominant stand-replacing natural disturbance in these forests. Since industrial-scale forestry is driven by economic motives, there is a risk that stands of higher economic value will be primarily harvested, thus threatening habitats, and functions related to these forests. Hence, the objective of this study was to identify the main attributes differentiating burned and logged stands prior to disturbance in boreal forests. The study territory lies in the coniferous and closed-canopy boreal forest in Québec, Canada, where industrial-scale logging and wildfire are the two main stand-replacing disturbances. Based on Québec government inventories of primary forests, we identified 427 transects containing about 5.5 circular field plots/transect that were burned or logged shortly after being surveyed, between 1985 and 2016. Comparative analysis of the main structural and environmental attributes of these transects highlighted the strong divergence in the impact of fire and harvesting on primary boreal forests. Overall, logging activities mainly harvested forests with the highest economic value, while most burned stands were low to moderately productive or recently disturbed. These results raise concerns about the resistance and resilience of remnant primary forests within managed areas, particularly in a context of disturbance amplification due to climate change. Moreover, the majority of the stands studied were old-growth forests, characterized by a high ecological value but also highly threatened by anthropogenic disturbances. A loss in the diversity and functionality of primary forests, and particularly the old-growth forests, therefore adds to the current issues related to these ecosystems. Since 2013, the study area is under ecosystem-based management, which implies that there have been marked changes in forestry practices. Complementary research will be necessary to assess the capacity of ecosystem-based management to address the challenges identified in our study.


2020 ◽  
Vol 50 (2) ◽  
pp. 155-169 ◽  
Author(s):  
Maxence Martin ◽  
Nicole J. Fenton ◽  
Hubert Morin

The erosion of old-growth forests in boreal managed landscapes is a major issue currently faced by forest managers; however, resolving this problem requires accurate surveys. The intention of our study was to determine if historic operational aerial forest surveys accurately identified boreal old-growth forests in Quebec, Canada. We first compared stand successional stages (even-aged vs. old-growth) in two aerial surveys performed in 1968 (preindustrial aerial survey) and 2007 (modern aerial survey) on the same 2200 km2 territory. Second, we evaluated the accuracy of the modern aerial survey by comparing its results with those of 74 field plots sampled in the study territory between 2014 and 2016. The two aerial surveys differed significantly; 80.8% of the undisturbed stands that were identified as “old-growth” in the preindustrial survey were classified as “even-aged” in the modern survey, and 60% of the stands identified as “old-growth” by field sampling were also erroneously identified as “even-aged” by the modern aerial survey. The scarcity of obvious old-growth attributes in boreal old-growth forests, as well as poorly adapted modern aerial survey criteria (i.e., criteria requiring high vertical stratification and significant changes in tree species composition along forest succession), were the main factors explaining these errors. It is therefore likely that most of Quebec’s boreal old-growth forests are currently not recognized as such in forest inventories, challenging the efficacy of sustainable forest management policies.


2020 ◽  
Vol 458 ◽  
pp. 117765 ◽  
Author(s):  
Maxence Martin ◽  
Yan Boucher ◽  
Nicole J. Fenton ◽  
Philippe Marchand ◽  
Hubert Morin

2010 ◽  
Vol 86 (2) ◽  
pp. 256-262 ◽  
Author(s):  
Joanne M Moyer ◽  
Peter N Duinker ◽  
Fay G Cohen

Old-growth forest is the subject of widespread conflict. Understanding associated values and attitudes in society is necessary for its sustainable management. We investigated old-growth values through a narrative study employing in-depth interviews with six leaders in Canada’s forest sector. Old-growth forest was valued for its natural ecological systems, biotic components, and experiential aspects. The study highlights the importance of value discourse within the forest sector. Key words: old-growth forest, values, Canada, forest management


2004 ◽  
Vol 80 (4) ◽  
pp. 458-462 ◽  
Author(s):  
Yves Bergeron

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


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