Activity levels of Marbled Murrelets in different inland habitats in the Queen Charlotte Islands, British Columbia

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 Condor ◽  
1993 ◽  
Vol 95 (4) ◽  
pp. 831-848 ◽  
Author(s):  
Michael S. Rodway ◽  
Heidi M. Regehr ◽  
Jean-Pierre L. Savard

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.


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.


1975 ◽  
Vol 53 (4) ◽  
pp. 418-433 ◽  
Author(s):  
Spencer G. Sealy

Two field seasons (1970 and 1971) were spent studying the feeding ecology of the ancient murrelet (Synthliboramphus antiquus) and the marbled murrelet (Brachyramphus marmoratus) near Langara Island, Queen Charlotte Islands, British Columbia. The relatively offshore-feeding ancient murrelet nests in colonies, lays two-egg clutches, and has truly precocial young. The inshore-feeding marbled murrelet is apparently a solitary nester, has one-egg clutches, and semiprecocial young. The ancient murrelet feeds predominantly on two species of euphausiid crustaceans, Euphausia pacifica and Thysanöessa spinifera, during the early portion of the terrestrial phase of its breeding cycle (early April to late May), but takes a fish, Ammodytes hexapterus, toward the end of the cycle. It is believed that this change in diet as the season progresses reflects a change in prey availability. The apparent patchy distribution of the prey of the ancient murrelet, which requires more time to locate the food source, has probably promoted the evolution of the 72-h incubation shifts found in this species.During the terrestrial phase of the marbled murrelet's breeding cycle (early May to late August), the fish Ammodytes hexapterus and Cymatogaster aggregata are predominantly taken. During the very early part of its breeding season, Thysanöessa spinifera constitutes a considerable part of its diet.


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.


Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 139 ◽  
Author(s):  
Susan K. Stevenson

Habitat management for woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia has generally focussed on protecting old-growth forests from logging. As that strategy becomes more difficult to maintain, biologists are beginning to explore opportunities to manage second-growth stands to provide arboreal lichens and other habitat resources important to caribou. Special harvesting and stand management practices are being developed and formulated into strategies for maintaining caribou populations in managed stands.


2008 ◽  
Vol 38 (12) ◽  
pp. 3098-3111 ◽  
Author(s):  
Allen Banner ◽  
Philip LePage

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.


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.


2005 ◽  
Vol 35 (6) ◽  
pp. 1411-1421 ◽  
Author(s):  
Arthur L Fredeen ◽  
Claudette H Bois ◽  
Darren T Janzen ◽  
Paul T Sanborn

Carbon (C) stocks were assessed for hybrid interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.)-dominated upland forests within the Aleza Lake Research Forest in central British Columbia, Canada. Four old-growth (141–250 years old) and four young second-growth (<20 years old) forest plots were established on the two dominant soil texture types, coarse and fine, for a total of 16 plots. Mean total C stocks for old-growth stands ranged from 423 Mg C·ha–1 (coarse) to 324 Mg C·ha–1 (fine), intermediate between Pacific Northwest temperate forests and upland boreal forests. Total C was lower in second-growth stands because of lower tree (mostly large tree stem), forest floor, and woody debris C stocks. In contrast, old-growth forest-floor C stocks ranged from 78 Mg C·ha–1 (coarse) to 35 Mg C·ha–1 (fine), 2.9- and 1.2-fold higher than in corresponding second-growth stands, respectively. Woody debris C stocks in old-growth stands totaled 35 Mg C·ha–1 (coarse) and 31 Mg C·ha–1 (fine), 2.7- and 3.4-fold higher than in second-growth stands, respectively. Mineral soil C to 1.07 m depth was similar across soil type and age-class, with totals ranging from 115 to 106 Mg C·ha–1. Harvesting of old-growth forests in sub-boreal British Columbia lowers total C stocks by 54%–41%.


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.


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