Chronoséquence après feu de la diversité de mammifères et d'oiseaux au nord de la forêt boréale québécoise

1995 ◽  
Vol 25 (9) ◽  
pp. 1509-1518 ◽  
Author(s):  
Michel Crête ◽  
Michel Crête ◽  
Bruno Drolet ◽  
Jean Huot ◽  
Marie-Josée Fortin ◽  
...  
Keyword(s):  
Fire Regime ◽  
Bird Species ◽  
Stand Age ◽  
Deer Mice ◽  
Forest Stands ◽  
Natural Fire ◽  
Forest Exploitation ◽  
The North ◽  
Dead Trees ◽  
Young Forests

Diversity of passerine birds and mammals was estimated in well-drained areas located at proximity of the hydroelectric reservoir La Grande-3, where natural fire regime still prevails in the absence of forest exploitation. Forest stands were divided up into four post-fire stages: (i) recent burns (4 years old), (ii) shrubs (25 years old), (iii) young forests (50 years old), and (iv) mature forests (≥71 years old). Richness and species diversity were highest in middle stages, in shrubs and young forests. The degree of opening seems to have affected more the composition of bird communities than stand age. Some bird species, typical of shrub stands, in particular white-crowned sparrow (Zonotrichialeucophrys Forster), Lincoln's sparrow (Melospizalincolnii Audubon), and alder flycatcher (Empidonaxalnorum Brewster), appeared after the falling of dead trees, ≈15 years after fire, and disappeared progressively as forests matured. Deer mice (Peromyscusmaniculatus Wagner), moose (Alcesalces L.), and black bears (Ursusamericanus Pallas) were more common at the beginning of succession, whereas northern red-backed voles (Clethrionomysgapperi Vigors) and caribou (Rangifertarandus L.) were typical of late stages. Mammal presence was mostly associated to their feeding requirements. Fire creates a mosaic of forest stands through periodic killing of trees in the north of the boreal forest, which contributes to maintain regional wildlife diversity; its suppression would reduce biodiversity.

Differences in bird species richness and abundance among three successional stages of aspen-dominated boreal forests

1995 ◽  
Vol 73 (8) ◽  
pp. 1417-1431 ◽  
Author(s):  
Jim Schieck ◽  
Marie Nietfeid ◽  
J. Brad Stelfox
Keyword(s):  
Species Richness ◽  
Boreal Forests ◽  
Bird Species ◽  
Bird Species Richness ◽  
Tree Cavities ◽  
Dead Trees ◽  
Large Trees ◽  
Successional Stages ◽  
Young Forests ◽  
Species Richness And Abundance

Birds and vegetation were surveyed in young, mature, and old aspen-dominated boreal forests in Alberta. Height and size of live trees, density of large dead trees, and volume of downed woody material increased during succession, whereas density of live trees decreased. Canopy heterogeneity had a bimodal relationship with succession: old forests had the highest, mature forests the lowest, and young forests an intermediate canopy heterogeneity. Old forests had greater bird species richness than young forests, which in turn had greater richness than mature forests. Twenty-seven, 3, and 10 bird species had their highest abundances in old, mature, and young forests, respectively. Seven bird species that nest and forage in canopy gaps and three bird species that nest and forage in large trees and snags were more abundant in young and old forests than in mature forests. Contrary to our predictions, patterns of richness and abundance for bird species that nest and forage in the canopy or in tree cavities were similar to those for bird species that nest or forage in the lower strata. Bird species preferring coniferous forests tended to be more abundant in old than in young or mature aspen-dominated forests, possibly because old aspen forests had more conifers than younger aspen forests.

scholarly journals SARS-CoV-2 infection and transmission in the North American deer mouse

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bryan D. Griffin ◽  
Mable Chan ◽  
Nikesh Tailor ◽  
Emelissa J. Mendoza ◽  
Anders Leung ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
North American ◽  
Direct Contact ◽  
Lower Respiratory Tract ◽  
Infectious Virus ◽  
Deer Mouse ◽  
Deer Mice ◽  
The North ◽  
Wild Deer ◽  
Theoretical Risk

AbstractWidespread circulation of SARS-CoV-2 in humans raises the theoretical risk of reverse zoonosis events with wildlife, reintroductions of SARS-CoV-2 into permissive nondomesticated animals. Here we report that North American deer mice (Peromyscus maniculatus) are susceptible to SARS-CoV-2 infection following intranasal exposure to a human isolate, resulting in viral replication in the upper and lower respiratory tract with little or no signs of disease. Further, shed infectious virus is detectable in nasal washes, oropharyngeal and rectal swabs, and viral RNA is detectable in feces and occasionally urine. We further show that deer mice are capable of transmitting SARS-CoV-2 to naïve deer mice through direct contact. The extent to which these observations may translate to wild deer mouse populations remains unclear, and the risk of reverse zoonosis and/or the potential for the establishment of Peromyscus rodents as a North American reservoir for SARS-CoV-2 remains unknown.

Influence of cliffs on bird community diversity

1998 ◽  
Vol 76 (2) ◽  
pp. 278-287 ◽  
Author(s):  
J D Matheson ◽  
D W Larson
Keyword(s):  
Bird Species ◽  
Bird Community ◽  
Community Diversity ◽  
Bird Species Richness ◽  
Narrow Component ◽  
Habitat Features ◽  
Habitat Mosaic ◽  
The North ◽  
Talus Slope ◽  
Additive Influence

Cliffs along the Niagara Escarpment in Ontario, Canada, support a long, narrow presettlement forest that includes three distinct geomorphic and vegetation zones: cliff edge, cliff face, and talus slope. This unique landform provides an opportunity to evaluate differences in bird communities between the escarpment and adjacent forest relative to habitat features. We sampled forest birds 12 times during the summer of 1994 in plots located in plateau forests, on talus slope, at cliff edges, and on cliff faces. Eleven habitat variables considered important to birds were also sampled in the plots. We arranged plots along six randomly spaced transects at a south site and a north site. Both sites had the consistent habitat heterogeneity considered important to birds. Bird species richness and composition responded to this heterogeneity, but differently at each site: plateau deciduous forests always had the lowest richness and the simplest species composition, whereas both cliff edges and talus slopes had a higher diversity of birds. Cliff faces had large numbers of species in the south but smaller numbers in the north. Escarpment zones form a habitat mosaic that supports many species not found in the adjacent forest and is consistent with the effect of habitat edge. The results suggest that cliffs represent a significant additive influence on avian biodiversity, even when the cliff is a very narrow component of the landscape.

scholarly journals SANITARY CONDITION OF PICEA ABIES (L. ) KARST. YOUNG FOREST STANDS DEPENDING ON THE SPATIAL SPECIFICITY

AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Jelena RUBA ◽  
Olga MIEZITE ◽  
Imants LIEPA
Keyword(s):  
Risk Factors ◽  
Picea Abies ◽  
Tree Height ◽  
Impact Factors ◽  
Forest Stands ◽  
Sanitary Condition ◽  
Young Forest ◽  
Young Forests ◽  
Spatial Specificity ◽  
Sanitary State

As a result of nature resources intensive use, most of ecosystems have beenconverted. Anthropogenic impact includes changes of forest stands structure andtheir spatial specificity in the forest area. Accordingly the sanitary state of Norwayspruce young forest stands can be affected by different risk impact factors ofmanagement. The aim of the research was to analyze the spruce Picea abies (L. )Karst. young forest stands sanitary condition depending on forest plots spatialspecificity and location in the forest areas. The data were collected in 4 regions ofLatvia in spruce young forest stands (1 - 40 years old). The research was conductedin young natural and artificial stands (pure – 44, mixed – 42). In total 502 sampleplots with a total area of 28250 mwere installed. The particular plot size (25, 50,100 and 200 m) were selected depending on the stand average tree height, whiletheir number depended on the forest stand area. A total area of investigated foreststands were 127. 5 hectares. Results showed that the expression of spatial specificsdepended on risk factors and their intensity, as well as the environmentalcharacteristics. Damages caused by abiotic risk factors at different forest standswere not the same regarding intensity, nature and volume, but more or less closelywere related to all site conditions. Spatial specificity of forest stands area (regularand irregular), as well as their location in the forest massif significantly affects thespruce young forests sanitary status (respectively p=0. 027 and p=0. 002). Differentrisk factors damage to forests, bordering with spruce or pine young growths,cutovers and various types of infrastructure, were identified as much moreimportant.

scholarly journals Evolutionary and Ecological Explanations for the Elevational Flexibility of Several East African Bird Species Complexes

2021 ◽  
Vol 9 ◽  
Author(s):  
Jon Fjeldså ◽  
Rauri C. K. Bowie
Keyword(s):  
Bird Species ◽  
Sky Islands ◽  
Coastal Forests ◽  
East African ◽  
The North ◽  
Breeding Populations ◽  
Species Complexes ◽  
Or Groups ◽  
Forest Mosaic ◽  
Distributional Dynamics

Africa’s montane areas are broken up into several large and small units, each isolated as forest-capped “sky islands” in a “sea” of dry lowland savanna. Many elements of their biota, including montane forest birds, are shared across several disjunct mountains, yet it has been difficult to rigorously define an Afromontane forest avifauna, or determine its evolutionary relationships with the birds of the surrounding lowland forests. In order to trace the historical relationship between lowland and highland avifaunas, we review cases of species or groups of closely related species with breeding populations at different elevations, and use phylogeographic methods to explore the historical connections between such populations within the biodiversity hotspot of East Africa. The study reveals several idiosyncratic patterns, but also a prominent number of cases of gene flow between populations in southern areas, mainly around the Malawi Rift, and mountains and coastal forests to the north, close to the equator. This may reflect more continuous past distributions through northern Mozambique and coastal Tanzania, or seasonal migrations between areas with different rainfall regimes. Over time, these distributional dynamics have resulted in a higher persistence of lineages, and an accumulation of forest-dependent lineages within the Eastern Arc Mountains of Tanzania and the northern part of the coastal forest mosaic.

scholarly journals The structure of forest stands in the Tatra National Park: The results of 2016–2017 inventory

2019 ◽  
Vol 80 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Jan Bodziarczyk ◽  
Jerzy Szwagrzyk ◽  
Tomasz Zwijacz-Kozica ◽  
Antoni Zięba ◽  
Janusz Szewczyk ◽  
...  
Keyword(s):  
Picea Abies ◽  
Fagus Sylvatica ◽  
National Park ◽  
Forest Stands ◽  
Protection Zone ◽  
Dead Trees ◽  
Standing Dead ◽  
Elevation Zone ◽  
Standing Dead Trees ◽  
Tatra National Park

Abstract The composition and structure of forest stands in the Tatra National Park were examined using data gathered in 2016 and 2017 from 617 circular sample plots (0.05 ha each). The diameter at breast height of all living trees, standing dead trees, snags, and wind throws was measured along with diameters and lengths of fallen logs within the plot boundaries. Tree height was measured for all living trees within the core (0.01 ha) of the sample plots. Using the obtained data, height-diameter curves were calculated for all major tree species and in the case of spruce, the height-diameter relationships were also calculated separately for each of the three elevation zones (up to 1200 m, between 1200 and 1400 m, above 1400 m). For each elevation zone and park protection zone, we also determined the volumes of live and dead trees. The volume of living trees in the Tatra National Park amounted to 259 m3/ha, which was higher than the volume of dead trees (176 m3/ha). Snags constituted the largest part of the dead wood whilst over 97% of the standing dead trees were spruce Picea abies. Among living trees, the share of spruce ranged from 81% in the low elevation zone to 98% in the middle zone. Other significant species in the lower zone were Abies alba (11%) and Fagus sylvatica (4.5%), while in the middle and upper elevation zones only Sorbus aucuparia occurred in significant numbers. Furthermore, in the lower elevation zone, Fagus sylvatica was the only species displaying significantly higher volumes in the ‘strict protection’ zone compared to the other park areas. In the ‘landscape protection’ zone, Picea abies was the most dominant species and the share of other species in the lowest elevation zones calculated based on tree density was smaller than calculated based on tree volume, indicating problems with stand conversion from spruce monoculture to mixed forest.

scholarly journals Repressive Policy of the Ussr Towards Certain Peoples in the Years of the Great Patriotic War (in Particular, the Bulgarians in the Urals)

TECHNOLOGOS ◽  
2021 ◽  
pp. 79-90
Author(s):  
Kamenskikh Mikhail
Keyword(s):  
Traditional Culture ◽  
Field Trip ◽  
The Urals ◽  
Forest Exploitation ◽  
Legal Documents ◽  
The North ◽  
Great Patriotic War ◽  
The Crimea ◽  
Perm Krai ◽  
History Of

The article is devoted to studying Russian Bulgarians living in the Urals in the 1940s with the help of archive materials of the Chelyabinsk and Sverdlovsk regions as well as Perm Krai. During the Great Patriotic War the USS Rcitizens of Bulgarian origin, like many other peoples, were subject to repressions which meant enrollment in labour army and deporting every single Bulgarian of the Crimea. As a result of the semeasures, a significant number of Bulgarians were moved to the territory of the modern Urals. The deported Bulgarians settled in areas of logging (forest exploitation) in the north of Molotov and Sverdlovsk regions, and members of the labour army were employed in the trust organization «Chelyabmetallurgstroi». The Bulgarians were deported along with other peoples of the Crimea. They did not form compact settlement in the new areas but managed to preserve their traditional culture. Some families were even able to organize permanent lodging in the Urals, pursue a career and contribute to the development of the region. The author is convinced that the judicial legal documents kept in archives as well as field trip research results may serve as a significant but not sufficiently appreciated source of investigating the history of deporting Russian Bulgarians. The topicality of the sources grew after the year 2020 when the 75-years’ period of storing documents of the year 1945 expired. Autobiographies, biographic information, interrogation protocols enable to obtain a detailed reconstruction of deportation circumstances and the process of enrollment into labour army, and to see these events through the prism of the repressed people themselves. Researching the history of repression, inparticular – repression of the Bulgarians – has revealed how complex and controversial the policy of the soviet state towards certain peoples during the Great Patriotic War was.

Mercury in lichens and reindeer hair from Alaska: 2005–2007 pilot survey

Polar Record ◽  
2009 ◽  
Vol 45 (4) ◽  
pp. 368-374 ◽  
Author(s):  
James A. Lokken ◽  
Gregory L. Finstad ◽  
Kriya L. Dunlap ◽  
Lawrence K. Duffy
Keyword(s):  
Industrial Development ◽  
Fire Regime ◽  
The Arctic ◽  
Metal Exposure ◽  
Non Invasive ◽  
The North ◽  
Invasive Method ◽  
Seward Peninsula ◽  
Arctic Food Web ◽  
Flooding Events

ABSTRACTReindeer and caribou are terrestrial herbivores, that feed on lichens and are used for commercial and subsistence food products. Caribou are a key component of the arctic food web and the bioaccumulation of toxic contaminants, such as mercury (Hg), needs to be monitored to establish a baseline as the arctic environment is impacted by both climate change and future industrial development. A changing climate in Alaska is influencing plant species composition, fire regime, melting and flooding events, and thus, impacting Hg bioavailability in the food chain. Industrial development in Asia is also projected to increase the atmospheric global pool of Hg from increased coal combustion. Reindeer, a domesticated representative of caribou, can be used as a terrestrial biomonitor for metal exposure. In this study total mercury concentrations were measured in lichens and in hair of grazing reindeer on defined ranges across Alaska to establish a baseline for future hypothesis development and testing regarding Hg deposition. The Hg mean level for Seward Peninsula lichens on the Davis Range was 37.4 ng g−1, on the Gray Range 47.1 ng g−1, on the Kakaruk Range 42.2 ng g−1, and 41.7 ng g−1 on the Noyakuk Range. Lichen Hg levels on St. Lawrence Island was 46.6 ng g−1. Methyl mercury levels in lichens were found to be below detection levels. Reindeer grazing on these ranges had mean Hg hair levels of 14.6 ng g−1 (Davis herd), 83.4 ng g−1 (Gray herd), and 40.3 ng g−1 (Noyakuk herd). Two reindeer on St. Lawrence Island had an average of Hg of 43.0 ng g−1. Sample sizes ranged from n = 2 to n = 11. Hg mean levels in lichen on Seward Peninsula were higher than Hg means of two ranges in northern Mongolia. The Hg levels observed in this study indicate that Hg levels in Alaska are low at this time and pose no risk to the health of reindeer or human subsistence harvesters. A significant relationship between Hg in lichens on the ranges and the Hg in reindeer on those ranges has not been established. There are insufficient data on Hg levels in many areas of the north and more information is needed on location specific and time trends in Hg concentrations. Lichens and reindeer hair provide a good, non-invasive method of monitoring metal exposure changes in Alaskan ecosystems.

Sign in / Sign up

Export Citation Format

Share Document