The eastern boreal old-growth balsam fir forest: a distinct ecosystem

2004 ◽  
Vol 82 (6) ◽  
pp. 830-849 ◽  
Author(s):  
Mireille Desponts ◽  
Geneviève Brunet ◽  
Louis Bélanger ◽  
Mathieu Bouchard

The objective of this project was to assess the importance of pristine forests in maintaining the botanical biodiversity of the humid boreal balsam fir forest of eastern Canada. The study was based on a comparative analysis of silviculturally mature second-growth stands and pristine forest stands at two stages of development (senescent and old growth) in the Gaspé Peninsula. The structure and composition of the stands was described, and the abundance of structural attributes evaluated. The communities of nonvascular plant species (mosses, liverworts), lichens, and saprophytic fungi were compared. The study demonstrated that the pristine forest landscape studied was composed largely of old-growth and senescent stands. Old-growth forests are differentiated by their irregular structure. The results regarding nonvascular plant species, lichens, and saprophytic fungi show higher species diversity in old-growth forests, corresponding to higher habitat diversity. Species assemblages were comparable between the pristine forests, but different from those of second-growth stands. Rare species are found more frequently in the old-growth forests. The results indicate that the old-growth balsam fir stands of the Gaspé Peninsula constitute critical habitats for maintaining a large number of species threatened by the gradual disappearance of primeval stands.Key words: forest management, biodiversity, old-growth forest, humid boreal fir forest, nonvascular plants.

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 304-326 ◽  
Author(s):  
John G. Blake ◽  
Bette A. Loiselle

Abstract Second growth has replaced lowland forest in many parts of the Neotropics, providing valuable habitat for many resident and migrant bird species. Given the prevalence of such habitats and the potential benefit for conservation of biodiversity, it is important to understand patterns of diversity in second growth and old growth. Descriptions of species-distribution patterns may depend, however, on method(s) used to sample birds. We used data from mist nets and point counts to (1) describe species diversity and community composition in second-growth (young and old) and old-growth forests at La Selva Biological Station, Costa Rica; and (2) to evaluate perspectives on community composition provided by the two methods. We recorded 249 species from 39 families, including 196 species captured in mist nets (10,019 captures) and 215 recorded during point counts (15,577 observations), which represents ∼78% of the terrestrial avifauna known from La Selva (excluding accidentals and birds characteristic of aquatic or aerial habitats). There were 32 threatened species, 22 elevational migrants, and 40 latitudinal migrants. Species richness (based on rarefaction analyses of capture and count data) was greatest in the youngest site. Latitudinal migrants were particularly common in second growth; elevational migrants were present in both young and old forest, but were more important in old-growth forest. Several threatened species common in second growth were not found in old-growth forests. Trophic composition varied less among sites than did species composition. Mist nets and point counts differed in numbers and types of species detected. Counts detected more species than nets in old-growth forest, but not in young second growth. Mist nets detected 62% of the terrestrial avifauna, and point counts detected 68%. Fifty-three species were observed but not captured, and 34 species were captured but not observed. Six families were not represented by mist-net captures. Data from mist nets and point counts both support the conclusion that second-growth vegetation provides habitat for many species.


1993 ◽  
Vol 71 (5) ◽  
pp. 977-984 ◽  
Author(s):  
Michael S. Rodway ◽  
Heidi M. Regehr ◽  
Jean-Pierre L. Savard

We compared Marbled Murrelet (Brachyramphus marmoratus) activity levels in May, June, and July 1990 in four habitats in the Queen Charlotte Islands, British Columbia: alpine, old-growth forest at high elevation, old-growth forest at low elevation, and second-growth forest. The number of Marbled Murrelet detections was highest in old-growth forests. In alpine areas, small numbers of murrelet detections were mostly of distant birds flying over low-elevation forest. Numbers of detections were higher in low-elevation than in high-elevation old-growth forests in May and July, but not in June. Proportions of detections within smaller radii of survey stations were higher in low elevation forest in all months. The highest activity levels were associated with old-growth forest stands of large Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla). The few detections that occurred in second-growth forests were mostly of distant birds. Stations in second-growth forest close to stands of old-growth forest had more frequent detections than stations with no old-growth forest nearby. Our results support the association of Marbled Murrelets with old-growth forests. Limitations of the survey methodology are discussed.


The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 132-148 ◽  
Author(s):  
John G. Blake ◽  
Bette A. Loiselle

AbstractWe used capture and recapture data (1985 to 1994) to examine seasonal variation in habitat use, movements within and among habitats, and survival rates of manakins (Manacus candei, Corapipo altera, Pipra mentalis, P. pipra) in northeastern Costa Rica. Manakins were captured in young and old second-growth woodlands in the lowlands and in old-growth forest at approximately 50, 500, and 1,000 m. Manakin species differed in their use of habitats, with old-growth forest species showing large and predictable seasonal variation in capture rates. Corapipo capture rates in lowland (nonbreeding) habitats were greater during the wet season than during the dry season and were greater in old-growth forest than in second growth. Capture rates at 500 m were higher in the dry season. Pipra mentalis capture rates were high in second growth and old growth. Capture rates were higher in the wet season and were correlated with capture rates of Corapipo, indicating that at least some individual P. mentalis migrate along the elevational gradient. P. pipra capture rates were highest at 1,000 m; few individuals descended to lowlands in the wet season. Manacus capture rates were highest in young second growth and did not vary between wet and dry seasons. Use of second-growth habitats by species typically associated with old-growth forests illustrates the value of maintaining a mosaic of habitats to accommodate seasonal changes in use of habitats. Contrary to expectations based on lek mating systems, there was little evidence that movements within habitats (i.e. recapture distances) varied between sexes. Yet, recapture percentages were higher in all species for adult females than males. Adult survival rates were ∼0.75 for Manacus in young second growth, 0.62 for Corapipo in old-growth forest at 50 m and 0.66 at 500 m, and 0.70 for Pipra mentalis in lowland old-growth forest. Results support the suggestion that geographic variation in survival rates may be common in the tropics and illustrate the need for examining survival rates separately by age and sex.


2020 ◽  
Author(s):  
Maxence Martin ◽  
Miguel Montoro Girona ◽  
Hubert Morin

AbstractOld-growth forests play a major role in conserving biodiversity, protecting water resources, sequestrating carbon, and these forests are indispensable resources for indigenous societies. To preserve the ecosystem services provided by these boreal ecosystems, it becomes necessary to develop novel silvicultural practices capable of emulating the natural dynamics and structural attributes of old-growth forests. The success of these forest management strategies depends on developing an accurate understanding of natural regeneration dynamics. Our goal was therefore to identify the main patterns and the drivers involved in the regeneration dynamics of old-growth forests, placing our focus on boreal stands dominated by black spruce (Picea mariana (L.) Mill.) and balsam fir (Balsam fir (L.) Mill.) in eastern Canada. We sampled 71 stands in a 2200 km2 study area located within Quebec’s boreal region. For each stand, we noted tree regeneration (seedlings and saplings), structural attributes (diameter distribution, deadwood volume, etc.), and abiotic (topography and soil) factors. We observed that secondary disturbance regimes and topographic constraints were the main drivers of balsam fir and black spruce regeneration. Furthermore, the regeneration dynamics of black spruce appeared more complex than those of balsam fir. We observed distinct phases of seedling production first developing within the understory, then seedling growth when gaps opened in the canopy, followed by progressive canopy closure. Seedling density, rather than the sapling density, had a major role in explaining the ability of black spruce to fill the canopy following a secondary disturbance. The density of balsam fir seedlings and saplings was also linked to the abundance of balsam fir trees at the stand level. This research helps explain the complexity of old-growth forest dynamics where many ecological factors interact at multiple temporal and spatial scales. This study also improves our understanding of ecological processes within native old-growth forests and identifies the key factors to consider when ensuring the sustainable management of old-growth boreal stands.


1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.


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.


1983 ◽  
Vol 7 (4) ◽  
pp. 208-212 ◽  
Author(s):  
Robert N. Muller

Abstract An old-growth forest and a 35-year-old, second-growth forest on the Cumberland Plateau were studied to compare species composition and structure. Species composition and total basal area of the two stands did not differ, although total stand density was 19 percent lower and basal area of commercial species was 25 percent higher in the old-growth than in the second-growth stand. Analysis of size-class distributions showed that both stands were best represented by an inverse J-shaped distribution, which best describes old-age stands. The rapid regeneration of the second-growth stand seems to be the result of minimal disturbance to accumulated nutrient pools in the soil. The importance of these accumulated nutrient pools and implications for forest management on the Cumberland Plateau are discussed.


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.


2006 ◽  
Vol 84 (1) ◽  
pp. 120-132 ◽  
Author(s):  
Rachel S. Botting ◽  
Arthur L. Fredeen

The diversity and abundance of terrestrial lichens, mosses, and liverworts were examined and compared between two ages of forest (old-growth and young second-growth) on two dominant soil types (fine- and coarse-textured soils) in subboreal spruce forests in central British Columbia. Major differences in species composition were found between forest ages, with 30% of species found only in old-growth forest and 21% found only in young second-growth forest. Liverworts were much more common in old-growth sites with half the liverwort species found exclusively in old-growth, and 90% of the recorded liverwort observations occurring there. Different moss species assemblages dominated old-growth and second-growth sites, with much of the terrestrial cover of second-growth sites composed of Polytrichum juniperinum Hedw. Young second-growth forest had higher cover of lichen species than old-growth forest. Lichens and bryophytes used different terrestrial substrates in each forest age, with higher cover of mosses and lichens occurring on woody substrates in old-growth, irrespective of substrate availability. Nonmetric multidimensional scaling ordination clearly separated plots by forest age and also showed soil texture to be a defining variable. Though not statistically significant, there was increased bryophyte diversity on coarse-textured soils and increased lichen cover on fine-textured soils.


1993 ◽  
Vol 69 (5) ◽  
pp. 569-578 ◽  
Author(s):  
Pierre Pominville

In 1985, an experiment was undertaken in the Gaspé peninsula, in Québec, in different stand types to assess the feasibility of preserving advance growth by changing logging methods. This article deals with manual felling combined with wheeled cable skidders in balsam fir stands. Regeneration was assessed before, immediately after, and 3 and 5 years after logging in five 2-ha pairs of blocks, in order to compare the effect of traditional harvesting (control) and a method using directional felling and spaced skidding trails (preserved).The use of directional felling and spaced skidding trails resulted in a decreased loss of advance growth. Five years after logging, this loss in softwood stocking for the preserved blocks was still lower in each of the five pairs; the difference averaged 25%. Moreover, the regeneration height in the preserved blocks was slightly greater, which seems to indicate a lower level of invasion by brush and herbaceous vegetation after logging as a result of this method.


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