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119 records – page 1 of 12.

[A case of the tick (Ixodidae) hiperinvasion of the tundra vole in magadan environs].

https://arctichealth.org/en/permalink/ahliterature289887
Source
Parazitologiia. 2017 Jan-Feb; 51(1):45-50
Publication Type
Case Reports
Journal Article
Author
N E Dokuchaev
Source
Parazitologiia. 2017 Jan-Feb; 51(1):45-50
Language
Russian
Publication Type
Case Reports
Journal Article
Keywords
Animals
Arvicolinae - parasitology
Fatal Outcome
Ixodes - pathogenicity - physiology
Male
Siberia
Tick Infestations - parasitology - pathology
Tundra
Abstract
A case of tundra vole death as a result its hyperinvasion by ticks Ixodes angustus on the northern periphery of the Asiatic range of the parasite is given.
PubMed ID
29401575 View in PubMed
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Alpine soil microbial ecology in a changing world.

https://arctichealth.org/en/permalink/ahliterature301151
Source
FEMS Microbiol Ecol. 2018 09 01; 94(9):
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Review
Date
09-01-2018
Author
Johanna Donhauser
Beat Frey
Author Affiliation
Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
Source
FEMS Microbiol Ecol. 2018 09 01; 94(9):
Date
09-01-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Review
Keywords
Arctic Regions
Biodiversity
Climate change
Ice Cover
Permafrost - chemistry - microbiology
Soil Microbiology
Tundra
Abstract
Climate change has a disproportionally large impact on alpine soil ecosystems, leading to pronounced changes in soil microbial diversity and function associated with effects on biogeochemical processes at the local and supraregional scales. However, due to restricted accessibility, high-altitude soils remain largely understudied and a considerable heterogeneity hampers the comparability of different alpine studies. Here, we highlight differences and similarities between alpine and arctic ecosystems, and we discuss the impact of climatic variables and associated vegetation and soil properties on microbial ecology. We consider how microbial alpha-diversity, community structures and function change along altitudinal gradients and with other topographic features such as slope aspect. In addition, we focus on alpine permafrost soils, harboring a surprisingly large unknown microbial diversity and on microbial succession along glacier forefield chronosequences constituting the most thoroughly studied alpine habitat. Finally, highlighting experimental approaches, we present climate change studies showing shifts in microbial community structures and function in response to warming and altered moisture, interestingly with some contradiction. Collectively, despite harsh environmental conditions, many specially adapted microorganisms are able to thrive in alpine environments. Their community structures strongly correlate with climatic, vegetation and soil properties and thus closely mirror the complexity and small-scale heterogeneity of alpine soils.
PubMed ID
30032189 View in PubMed
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Amplification of plant volatile defence against insect herbivory in a warming Arctic tundra.

https://arctichealth.org/en/permalink/ahliterature302856
Source
Nat Plants. 2019 06; 5(6):568-574
Publication Type
Letter
Research Support, Non-U.S. Gov't
Date
06-2019
Author
Tao Li
Thomas Holst
Anders Michelsen
Riikka Rinnan
Author Affiliation
Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark. tao.li@bio.ku.dk.
Source
Nat Plants. 2019 06; 5(6):568-574
Date
06-2019
Language
English
Publication Type
Letter
Research Support, Non-U.S. Gov't
Keywords
Animals
Betula - immunology - parasitology
Ecosystem
Global warming
Herbivory
Insecta - physiology
Tundra
Volatile Organic Compounds - metabolism
Abstract
Plant-emitted volatile organic compounds (VOCs) play fundamental roles in atmospheric chemistry and ecological processes by contributing to aerosol formation1 and mediating species interactions2. Rising temperatures and the associated shifts in vegetation composition have been shown to be the primary drivers of plant VOC emissions in Arctic ecosystems3. Although herbivorous insects also strongly alter plant VOC emissions2, no studies have addressed the impact of herbivory on plant VOC emissions in the Arctic. Here we show that warming dramatically increases the amount, and alters the blend, of VOCs released in response to herbivory. We observed that a tundra ecosystem subjected to warming, by open-top chambers, for 8 or 18 years showed a fourfold increase in leaf area eaten by insect herbivores. Herbivory by autumnal moth (Epirrita autumnata) larvae, and herbivory-mimicking methyl jasmonate application, on the widespread circumpolar dwarf birch (Betula nana) both substantially increased emissions of terpenoids. The long-term warming treatments and mimicked herbivory caused, on average, a two- and fourfold increase in monoterpene emissions, respectively. When combined, emissions increased 11-fold, revealing a strong synergy between warming and herbivory. The synergistic effect was even more pronounced for homoterpene emissions. These findings suggest that, in the rapidly warming Arctic, insect herbivory may be a primary determinant of VOC emissions during periods of active herbivore feeding.
PubMed ID
31182843 View in PubMed
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The annual, temporal and spatial pattern of Setaria tundra outbreaks in Finnish reindeer: a mechanistic transmission model approach.

https://arctichealth.org/en/permalink/ahliterature297847
Source
Parasit Vectors. 2018 Nov 12; 11(1):565
Publication Type
Journal Article
Date
Nov-12-2018
Author
Najmul Haider
Sauli Laaksonen
Lene Jung Kjær
Antti Oksanen
Rene Bødker
Author Affiliation
National Veterinary Institute, Technical University of Denmark, Kgs. Lyngby, Denmark. najha@vet.dtu.dk.
Source
Parasit Vectors. 2018 Nov 12; 11(1):565
Date
Nov-12-2018
Language
English
Publication Type
Journal Article
Keywords
Animals
Climate change
Culicidae - parasitology
Disease Outbreaks
Female
Finland - epidemiology
Larva
Microclimate
Models, Theoretical
Peritonitis
Reindeer - parasitology
Seasons
Setaria Nematode - isolation & purification
Setariasis - epidemiology - parasitology - transmission
Spatio-Temporal Analysis
Temperature
Tundra
Abstract
In northern Finland (Lapland), reindeer are reared as semi-domesticated animals. The region has a short summer season of 2-3 months, yet reindeer are infected with the mosquito-borne filarioid parasite Setaria tundra. The infection causes peritonitis and perihepatitis, which cause significant economic losses due to reduced body weight of infected animals. The objective of this study was to: (i) describe the spatial and temporal pattern of outbreaks in three different areas across Finnish Lapland; and (ii) construct a temperature-driven mechanistic transmission model to quantify the potential role of temperature on intensity of S. tundra transmission in reindeer.
We developed a temperature-driven transmission model able to predict the number of S. tundra potentially transmitted from an infectious reindeer. We applied the model to the years 2004-2015, and compared the predictions to the proportion of reindeer whose livers were condemned due to S. tundra infection at the time of slaughter.
The mean proportion of liver condemnation increased in reindeer slaughtered in late autumn/winter compared to earlier dates. The outbreaks were geographically clustered each year but there were no fixed foci where outbreaks occurred. Larger outbreaks were recorded in the southern regions of reindeer-herding areas compared to the central or northern parts of Lapland. Our model showed that temperatures never allowed for transmission of more than a single generation of S. tundra each season. In southern (Kuusamo) and central (Sodankylä) Lapland, our model predicted an increasing trend from 1979 to 2015 for both the duration of the effective transmission period of S. tundra (P
PubMed ID
30415639 View in PubMed
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Antechiniella septentrionalis n. sp. (Spirurida: Acuariidae), a new intestinal nematode parasite of the tundra vole Microtus oeconomus (Pallas) (Rodentia: Muridae) in the north-east of Russia.

https://arctichealth.org/en/permalink/ahliterature301622
Source
J Helminthol. 2019 Jul; 93(4):494-503
Publication Type
Journal Article
Date
Jul-2019
Author
E S Ivanova
N E Dokuchaev
S E Spiridonov
Author Affiliation
Centre of Parasitology of A.N. Severtsov Institute of Ecology and Evolution RAS,Leninskii prospect 33,119071, Moscow,Russia.
Source
J Helminthol. 2019 Jul; 93(4):494-503
Date
Jul-2019
Language
English
Publication Type
Journal Article
Keywords
Animals
Arvicolinae - parasitology
Female
Intestinal Diseases, Parasitic - parasitology - veterinary
Phylogeny
Russia
Spirurida - genetics - isolation & purification
Tundra
Abstract
Antechiniella septentrionalis n. sp. (Spirurida: Acuariidae) is described from the duodenum of a tundra vole, Microtus oeconomus (Pallas), collected in the Magadan region in the north-east part of Russia. It differs from A. suffodiax (Beveridge & Barker, 1975) and A. sertatum Smales, 1991 mainly in having a larger number of postcloacal papillae (5-6 pairs vs 4 pairs), a differently shaped left spicule, the disposition of precloacal papillae in two rows vs one, and oblong vs oval eggs. Other differences include the different disposition of ovaries in A. septentrionalis n. sp and A. suffodiax and the different structure of deirids in A. septentrionalis n. sp. and A. sertatum. The new species was characterized molecularly (partial sequences for 18S rRNA, 28S rRNA and cox1 mtDNA). The phylogenetic analyses performed showed the affinity of the new species to the members of the Acuariidae and other spirurid nematodes.
PubMed ID
29759087 View in PubMed
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Arctic shrub colonization lagged peak postglacial warmth: Molecular evidence in lake sediment from Arctic Canada.

https://arctichealth.org/en/permalink/ahliterature308679
Source
Glob Chang Biol. 2019 Dec; 25(12):4244-4256
Publication Type
Journal Article
Date
Dec-2019
Author
Sarah E Crump
Gifford H Miller
Matthew Power
Julio Sepúlveda
Nadia Dildar
Megan Coghlan
Michael Bunce
Author Affiliation
Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA.
Source
Glob Chang Biol. 2019 Dec; 25(12):4244-4256
Date
Dec-2019
Language
English
Publication Type
Journal Article
Keywords
Arctic Regions
Canada
Climate change
Lakes
Tundra
Abstract
Arctic shrubification is an observable consequence of climate change, already resulting in ecological shifts and global-scale climate feedbacks including changes in land surface albedo and enhanced evapotranspiration. However, the rate at which shrubs can colonize previously glaciated terrain in a warming world is largely unknown. Reconstructions of past vegetation dynamics in conjunction with climate records can provide critical insights into shrubification rates and controls on plant migration, but paleoenvironmental reconstructions based on pollen may be biased by the influx of exotic pollen to tundra settings. Here, we reconstruct past plant communities using sedimentary ancient DNA (sedaDNA), which has a more local source area than pollen. We additionally reconstruct past temperature variability using bacterial cell membrane lipids (branched glycerol dialkyl glycerol tetraethers) and an aquatic productivity indicator (biogenic silica) to evaluate the relative timing of postglacial ecological and climate changes at a lake on southern Baffin Island, Arctic Canada. The sedaDNA record tightly constrains the colonization of dwarf birch (Betula, a thermophilous shrub) to 5.9 ± 0.1 ka, ~3 ka after local deglaciation as determined by cosmogenic 10 Be moraine dating and >2 ka later than Betula pollen is recorded in nearby lake sediment. We then assess the paleovegetation history within the context of summer temperature and find that paleotemperatures were highest prior to 6.3 ka, followed by cooling in the centuries preceding Betula establishment. Together, these molecular proxies reveal that Betula colonization lagged peak summer temperatures, suggesting that inefficient dispersal, rather than climate, may have limited Arctic shrub migration in this region. In addition, these data suggest that pollen-based climate reconstructions from high latitudes, which rely heavily on the presence and abundance of pollen from thermophilous taxa like Betula, can be compromised by both exotic pollen fluxes and vegetation migration lags.
PubMed ID
31603617 View in PubMed
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Arctic tundra soil bacterial communities active at subzero temperatures detected by stable isotope probing.

https://arctichealth.org/en/permalink/ahliterature307949
Source
FEMS Microbiol Ecol. 2020 02 01; 96(2):
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
02-01-2020
Author
Preshita S Gadkari
Lora R McGuinness
Minna K Männistö
Lee J Kerkhof
Max M Häggblom
Author Affiliation
School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick NJ 08901, USA.
Source
FEMS Microbiol Ecol. 2020 02 01; 96(2):
Date
02-01-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Bacteria - genetics - isolation & purification
Carbon
Climate change
Finland
Microbiota
Permafrost - microbiology
Phylogeny
RNA, Ribosomal, 16S
Soil Microbiology
Temperature
Tundra
Abstract
Arctic soils store vast amounts of carbon and are subject to intense climate change. While the effects of thaw on the composition and activities of Arctic tundra microorganisms has been examined extensively, little is known about the consequences of temperature fluctuations within the subzero range in seasonally frozen or permafrost soils. This study identified tundra soil bacteria active at subzero temperatures using stable isotope probing (SIP). Soils from Kilpisjärvi, Finland, were amended with 13C-cellobiose and incubated at 0, -4 and -16°C for up to 40 weeks. 16S rRNA gene sequence analysis of 13C-labelled DNA revealed distinct subzero-active bacterial taxa. The SIP experiments demonstrated that diverse bacteria, including members of Candidatus Saccharibacteria, Melioribacteraceae, Verrucomicrobiaceae, Burkholderiaceae, Acetobacteraceae, Armatimonadaceae and Planctomycetaceae, were capable of synthesising 13C-DNA at subzero temperatures. Differences in subzero temperature optima were observed, for example, with members of Oxalobacteraceae and Rhizobiaceae found to be more active at 0°C than at -4°C or -16°C, whereas Melioribacteriaceae were active at all subzero temperatures tested. Phylogeny of 13C-labelled 16S rRNA genes from the Melioribacteriaceae, Verrucomicrobiaceae and Candidatus Saccharibacteria suggested that these taxa formed subzero-active clusters closely related to members from other cryo-environments. This study demonstrates that subzero temperatures impact active bacterial community composition and activity, which may influence biogeochemical cycles.
PubMed ID
31778159 View in PubMed
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Atmosphere-terrestrial exchange of gaseous elemental mercury: parameterization improvement through direct comparison with measured ecosystem fluxes.

https://arctichealth.org/en/permalink/ahliterature308888
Source
Environ Sci Process Impacts. 2019 Oct 16; 21(10):1699-1712
Publication Type
Journal Article
Date
Oct-16-2019
Author
T R Khan
D Obrist
Y Agnan
N E Selin
J A Perlinger
Author Affiliation
Department of Civil and Environmental Engineering, Michigan Technological University, Houghton, MI 49931, USA. trkhan@mtu.edu.
Source
Environ Sci Process Impacts. 2019 Oct 16; 21(10):1699-1712
Date
Oct-16-2019
Language
English
Publication Type
Journal Article
Keywords
Air Pollutants - analysis - chemistry
Alaska
Atmosphere - chemistry
Ecosystem
Environmental Monitoring - methods
Grassland
Mercury - analysis - chemistry
Seasons
Soil - chemistry
Switzerland
Tundra
Abstract
To simulate global mercury (Hg) dynamics in chemical transport models (CTMs), surface-atmosphere exchange of gaseous elemental mercury, Hg0, is often parameterized based on resistance-based dry deposition schemes coupled with a re-emission function, mainly from soils. Despite extensive use of this approach, direct evaluations of this implementation against field observations of net Hg0 exchange are lacking. In this study, we evaluate an existing net exchange parameterization (referred to here as the base model) by comparing modeled fluxes of Hg0 to fluxes measured in the field using micrometeorological techniques. Comparisons were performed in two terrestrial ecosystems: a grassland site in Switzerland and an Arctic tundra site in Alaska, U.S., each including summer and winter seasons. The base model included the dry deposition and soil re-emission parameterizations from Zhang et al. (2003) and the global CTM GEOS-Chem, respectively. Comparisons of modeled and measured Hg0 fluxes showed large discrepancies, particularly in the summer months when the base model overestimated daytime net deposition by approximately 9 and 2 ng m-2 h-1 at the grassland and tundra sites, respectively. In addition, the base model was unable to capture a measured nighttime net Hg0 deposition and wintertime deposition. We conducted a series of sensitivity analyses and recommend that Hg simulations using CTMs: (i) reduce stomatal uptake of Hg0 over grassland and tundra in models by a factor 5-7; (ii) increase nighttime net Hg0 deposition, e.g., by increasing ground and cuticular uptake by reducing the respective resistance terms by factors of 3-4 and 2-4, respectively; and (iii) implement a new soil re-emission parameterization to produce larger daytime emissions and lower nighttime emissions. We also compared leaf Hg0 uptake over the growing season estimated by the dry deposition model against foliar Hg measurements, which revealed good agreement with the measured leaf Hg concentrations after adjusting the base model as suggested above. We conclude that the use of resistance-based models combined with the new soil re-emission flux parameterization is able to reproduce observed diel and seasonal patterns of Hg0 exchange in these ecosystems. This approach can be used to improve model parameterizations for other ecosystems if flux measurements become available.
PubMed ID
31549133 View in PubMed
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Bioavailable soil phosphorus decreases with increasing elevation in a subarctic tundra landscape.

https://arctichealth.org/en/permalink/ahliterature268853
Source
PLoS One. 2014;9(3):e92942
Publication Type
Article
Date
2014
Author
Andrea G Vincent
Maja K Sundqvist
David A Wardle
Reiner Giesler
Source
PLoS One. 2014;9(3):e92942
Date
2014
Language
English
Publication Type
Article
Keywords
Ecosystem
Geography
Phosphorus - chemistry
Soil - chemistry
Sweden
Tundra
Abstract
Phosphorus (P) is an important macronutrient in arctic and subarctic tundra and its bioavailability is regulated by the mineralization of organic P. Temperature is likely to be an important control on P bioavailability, although effects may differ across contrasting plant communities with different soil properties. We used an elevational gradient in northern Sweden that included both heath and meadow vegetation types at all elevations to study the effects of temperature, soil P sorption capacity and oxalate-extractable aluminium (Alox) and iron (Feox) on the concentration of different soil P fractions. We hypothesized that the concentration of labile P fractions would decrease with increasing elevation (and thus declining temperature), but would be lower in meadow than in heath, given that N to P ratios in meadow foliage are higher. As expected, labile P in the form of Resin-P declined sharply with elevation for both vegetation types. Meadow soils did not have lower concentrations of Resin-P than heath soils, but they did have 2-fold and 1.5-fold higher concentrations of NaOH-extractable organic P and Residual P, respectively. Further, meadow soils had 3-fold higher concentrations of Alox + Feox and a 20% higher P sorption index than did heath soils. Additionally, Resin-P expressed as a proportion of total soil P for the meadow was on average half that in the heath. Declining Resin-P concentrations with elevation were best explained by an associated 2.5-3.0 °C decline in temperature. In contrast, the lower P availability in meadow relative to heath soils may be associated with impaired organic P mineralization, as indicated by a higher accumulation of organic P and P sorption capacity. Our results indicate that predicted temperature increases in the arctic over the next century may influence P availability and biogeochemistry, with consequences for key ecosystem processes limited by P, such as primary productivity.
Notes
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PubMed ID
24676035 View in PubMed
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Biotic responses buffer warming-induced soil organic carbon loss in Arctic tundra.

https://arctichealth.org/en/permalink/ahliterature297735
Source
Glob Chang Biol. 2018 10; 24(10):4946-4959
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
10-2018
Author
Junyi Liang
Jiangyang Xia
Zheng Shi
Lifen Jiang
Shuang Ma
Xingjie Lu
Marguerite Mauritz
Susan M Natali
Elaine Pegoraro
Christopher Ryan Penton
César Plaza
Verity G Salmon
Gerardo Celis
James R Cole
Konstantinos T Konstantinidis
James M Tiedje
Jizhong Zhou
Edward A G Schuur
Yiqi Luo
Author Affiliation
Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma.
Source
Glob Chang Biol. 2018 10; 24(10):4946-4959
Date
10-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Alaska
Carbon - analysis - metabolism
Climate change
Models, Theoretical
Permafrost - chemistry - microbiology
Photosynthesis
Plants - metabolism
Soil - chemistry
Soil Microbiology
Tundra
Abstract
Climate warming can result in both abiotic (e.g., permafrost thaw) and biotic (e.g., microbial functional genes) changes in Arctic tundra. Recent research has incorporated dynamic permafrost thaw in Earth system models (ESMs) and indicates that Arctic tundra could be a significant future carbon (C) source due to the enhanced decomposition of thawed deep soil C. However, warming-induced biotic changes may influence biologically related parameters and the consequent projections in ESMs. How model parameters associated with biotic responses will change under warming and to what extent these changes affect projected C budgets have not been carefully examined. In this study, we synthesized six data sets over 5 years from a soil warming experiment at the Eight Mile Lake, Alaska, into the Terrestrial ECOsystem (TECO) model with a probabilistic inversion approach. The TECO model used multiple soil layers to track dynamics of thawed soil under different treatments. Our results show that warming increased light use efficiency of vegetation photosynthesis but decreased baseline (i.e., environment-corrected) turnover rates of SOC in both the fast and slow pools in comparison with those under control. Moreover, the parameter changes generally amplified over time, suggesting processes of gradual physiological acclimation and functional gene shifts of both plants and microbes. The TECO model predicted that field warming from 2009 to 2013 resulted in cumulative C losses of 224 or 87 g/m2 , respectively, without or with changes in those parameters. Thus, warming-induced parameter changes reduced predicted soil C loss by 61%. Our study suggests that it is critical to incorporate biotic changes in ESMs to improve the model performance in predicting C dynamics in permafrost regions.
PubMed ID
29802797 View in PubMed
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119 records – page 1 of 12.