Breeding Bird Communities in Boreal Forest of Western Canada: Consequences of "Unmixing" the Mixedwoods

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 759-769 ◽  
Author(s):  
Keith A. Hobson ◽  
Erin Bayne
Keyword(s):  
Boreal Forest ◽  
Bird Communities ◽  
Western Canada ◽  
Breeding Bird

Erratum: Breeding bird communities of western and northern Canadian boreal forest: relationship to forest type

1997 ◽  
Vol 75 (1) ◽  
pp. 157-159
Author(s):  
David A. Kirk ◽  
Anthony W. Diamond ◽  
Keith A. Hobson ◽  
Alan R. Smith
Keyword(s):  
Boreal Forest ◽  
Forest Type ◽  
Bird Communities ◽  
Breeding Bird ◽  
Canadian Boreal Forest

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

scholarly journals Microbial Substrate Utilization and Vegetation Shifts in Boreal Forest Floors of Western Canada

2021 ◽  
Vol 4 ◽  
Author(s):  
Emily Lloret ◽  
Sylvie Quideau
Keyword(s):  
Boreal Forest ◽  
Microbial Communities ◽  
Forest Floor ◽  
Microbial Respiration ◽  
Substrate Utilization ◽  
Utilization Efficiency ◽  
Western Canada ◽  
Spruce Forest ◽  
Vegetation Shifts ◽  
Forest Floors

Boreal forest soils are highly susceptible to global warming, and in the next few decades, are expected to face large increases in temperature and transformative vegetation shifts. The entire boreal biome will migrate northward, and within the main boreal forest of Western Canada, deciduous trees will replace conifers. The main objective of our research was to assess how these vegetation shifts will affect functioning of soil microbial communities and ultimately the overall persistence of boreal soil carbon. In this study, aspen and spruce forest floors from the boreal mixedwood forest of Alberta were incubated in the laboratory for 67 days without (control) and with the addition of three distinct 13C labeled substrates (glucose, aspen leaves, and aspen roots). Our first objective was to compare aspen and spruce substrate utilization efficiency (SUE) in the case of a labile C source (13C-glucose). For our second objective, addition of aspen litter to spruce forest floor mimicked future vegetation shifts, and we tested how this would alter substrate use efficiency in the spruce forest floor compared to the aspen. Tracking of carbon utilization by microbial communities was accomplished using 13C-PLFA analysis, and 13C-CO2 measurements allowed quantification of the relative contribution of each added substrate to microbial respiration. Following glucose addition, the aspen community showed a greater 13C-PLFA enrichment than the spruce throughout the 67-day incubation. The spruce community respired a greater amount of 13C glucose, and it also had a much lower glucose utilization efficiency compared to the aspen. Following addition of aspen litter, in particular aspen leaves, the aspen community originally showed greater total 13C-PLFA enrichment, although gram positive phospholipid fatty acids (PLFAs) were significantly more enriched in the spruce community. While the spruce community respired a greater amount of the added 13C-leaves, both forest floor types showed comparable substrate utilization efficiencies by Day 67. These results indicate that a shift from spruce to aspen may lead to a greater loss of the aspen litter through microbial respiration, but that incorporation into microbial biomass and eventually into the more persistent soil carbon pool may not be affected.

scholarly journals A Possible Role for Red Squirrels in Structuring Breeding Bird Communities in Lodgepole Pine Forests

The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 232-238 ◽  
Author(s):  
Adam M. Siepielski
Keyword(s):  
Nest Predation ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Bird Communities ◽  
Pine Forests ◽  
Tamiasciurus Hudsonicus ◽  
Breeding Bird ◽  
Bird Abundance ◽  
Red Squirrels ◽  
Cavity Nesters

Abstract Nest predation is thought to play an important role in structuring certain breeding bird communities. One potential consequence of nest predation is lower recruitment in breeding birds, which may be manifested as lower breeding bird abundance. Lodgepole pine (Pinus contorta ssp. latifolia) forests east and west of the Rocky Mountains became isolated following glacial retreat 12 000 years ago and differ in whether or not red squirrels (Tamiasciurus hudsonicus), which are a key nest predator, are present. Breeding bird abundance in lodgepole pine forests was compared between four ranges with red squirrels and four ranges without red squirrels. Species grouped into canopy and understory nesting guilds were, on average, two and three times more abundant, respectively, in forest ranges without red squirrels than in ranges with red squirrels; no statistically significant differences were found for midstory, ground, or cavity nesters. These results suggest that geographic variation in the presence or absence of red squirrels is likely important in structuring breeding bird communities in lodgepole pine forests across the landscape.

scholarly journals Sea to sky: impacts of residual salmon-derived nutrients on estuarine breeding bird communities

2011 ◽  
Vol 278 (1721) ◽  
pp. 3081-3088 ◽  
Author(s):  
Rachel D. Field ◽  
John D. Reynolds
Keyword(s):  
Pacific Salmon ◽  
Bird Communities ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Breeding Bird ◽  
The North ◽  
Bird Density ◽  
Post Spawning ◽  
The North Pacific ◽  
Forest Habitats

Pacific salmon ( Oncorhynchus spp.) returning to streams around the North Pacific Rim provide a nutrient subsidy to these ecosystems. While many species of animals feed directly on salmon carcasses each autumn, salmon-derived nutrients can also be stored in coastal habitats throughout the year. The effects of this storage legacy on vertebrates in other seasons are not well understood, especially in estuaries, which can receive a large portion of post-spawning salmon nutrients. We examine the effects of residual salmon-derived nutrients, forest habitats and landscape features on summer breeding birds in estuary forests. We compared models containing environmental variables and combined chum ( Oncorhynchus keta ) and pink ( Oncorhynchus gorbuscha ) salmon biomass to test predictions concerning bird density and diversity. We discovered that total bird, insectivore, golden-crowned kinglet and Pacific wren densities and Shannon's diversity in the summer were strongly predicted by salmon biomass in the autumn. For most metrics, this relationship approaches an asymptote beyond 40 000 kg of salmon biomass. Foliage height diversity, watershed catchment area and estuary area were also important predictors of avian communities. Our study suggests that the legacy of salmon nutrients influences breeding bird density and diversity in estuaries that vary across a wide gradient of spawning salmon biomass.

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