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Niels M. Schmidt, Olivier Gilg, Jon Aars, Rolf A. Ims. (2021). Fat, Furry, Flexible, and Functionally Important: Characteristics of Mammals Living in the Arctic.
Abstract: Mammals constitute a group of vertebrates that share a number of unique characteristics,such as nursing their young with milk, and having hair. The pattern of low mammal species diversity in the Arctic probably reflects a combination of mainly two driving factors: first, being homeotherms, mammals require a substantial amount of energy to sustain the various life processes, and the arctic regions are characterized by a very low availability of energy due to short seasons for primary production. Secondly, the occurrence of arctic mammals today reflects the reinvasion of the mammal species into the Arctic as the ecosystems were re-established following the deglaciation. This chapter discusses the characteristics of the arctic mammals, including their unique adaptations to life, and their role as both consumer and food base in the arctic ecosystems. Climate change in the Arctic may also alter the interactions within food webs.
Keywords: arctic ecosystems Arctic mammals climate change deglaciation food webs homeotherms low mammal species diversity primary production
Programme: 1036
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. (2021). Incisor microwear of Arctic rodents as a proxy for microhabitat preference (Vol. 101).
Abstract: Changing environmental conditions in the Arctic make it important to document and understand habitat preferences and flexibility of vulnerable high-latitude mammals. Indirect proxies are especially useful for elusive species, such as rodents. This study explores incisor microwear as an indicator of variation in behavior and microhabitat use in Siberian lemmings (Lemmus sibiricus) and narrow-headed voles (Lasiopodomys gregalis) from the Yamal Peninsula, Russia. Fifty-nine individuals were sampled at four sites along a latitudinal gradient from forest-tundra ecotone to high-Arctic tundra. Lemmings are present at the northernmost site, voles at the southernmost site, and both species at the middle two. Lemmus sibiricus prefers wet, mossy lowland, whereas La. gregalis favors drier thickets and more open microhabitats and burrows underground. Feature-based analyses indicate higher densities of features and more uniformly oriented striations for voles than lemmings at sites with both species. The species also differ significantly in microwear texture attributes suggesting larger features for lemmings, and smaller ones, but more of them, for voles. While no texture differences were found between sites within species, voles from sites with open tundra have higher striation densities than those from the forest-tundra ecotone. Furthermore, lemmings from open tundra sites have higher striation densities than those from the water-saturated, moss-covered northernmost site. While microhabitat preferences and burrowing by voles likely contribute to differences between species, variation within seems to reflect habitat variation given differences in abrasive loads between sites. This suggests that incisor microwear patterning can be used to track microhabitat differences among Arctic rodent populations.
Keywords: Arctic Environment Habitats Narrow-headed vole Russia Siberian lemming Tooth wear Tundra Yamal Peninsula
Programme: 1036
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. (2021). Multispecies tracking reveals a major seabird hotspot in the North Atlantic (Vol. 14). Bachelor's thesis, , .
Keywords: area beyond national jurisdiction Atlantic biologging conservation high seas marine protected area regional seas convention
Programme: 330,333,388,1036
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Guillaume Hubert. (2021). Analyses of the Secondary Cosmic Ray using CCD camera in high-altitude observatories and Antarctica stations (Vol. 395).
Abstract: Charge-Coupled Device (CCD) and Array Pixel Sensors (APS) can be used to image radiation-induced energy deposition. The high sensitivity of depleted silicon to ionizing radiation constitutes an opportunity to investigate radiation effects while it is a nuisance to astronomer activities. CCD and APS provide a better combination of spatial and intensity resolution for radiation events than other available types of detector. This paper proposes to analyze radiation events observed in the CCD camera and more specifically analyses of charge deposition spectra and spatially extensive events. Measurements were performed in the Pic du Midi from 2011 to 2015 and in the Concordia Antarctica station since 2018. Coupled transport models (i.e. particle transport and charge transport in semiconductors) allow investigating contributions to charge collection spectra as a function of the particle nature, i.e. neutron, proton and muon. Coupled measurements and simulations allow to access to the detected secondary CR flux and the charge deposition pattern. Results showed that high charge level events seen on atmospheric sites can be considered as hadronic component (mainly neutrons and protons) while low charge levels and punctual events are induced by muons which are able to generate up to 3 fC in the CCD camera. Hence, thanks to double level of measurement sites, muon discrimination from other secondary particles has been investigated. Cross-comparison analyses based on CCD and neutron spectrometers operated in both station/observatory investigate secondary CR dynamic.
Keywords: Array Pixel Sensors (APS) Charge-Coupled Device (CCD)
Programme: 1112
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Damien Ertz, Neil Sanderson, Marc Lebouvier. (2021). Thelopsis challenges the generic circumscription in the Gyalectaceae and brings new insights to the taxonomy of Ramonia (Vol. 53).
Abstract: The genus Thelopsis was classified in the family Stictidaceae but its systematic position has never been investigated by molecular methods. In order to determine its family placement and to test its monophyly, fungal DNA of recent collections of Thelopsis specimens was sequenced. Phylogenetic analyses using nuLSU, RPB2 and mtSSU sequences reveal that members of Thelopsis form a monophyletic group within the genus Gyalecta as currently accepted. The placement of Thelopsis, including the generic type T. rubella, within the genus Gyalecta challenges the generic circumscription of this group because Thelopsis is well recognized by the combination of morphological characters: perithecioid ascomata, well-developed periphysoids, polysporous asci and small, few-septate ellipsoid-oblong ascospores. The sterile sorediate Opegrapha corticola is also placed in the Gyalectaceae as sister species to Thelopsis byssoidea + T. rubella. Ascomata of O. corticola are illustrated for the first time and support its placement in the genus Thelopsis. The hypothesis that O. corticola might represent the sorediate fertile morph of T. rubella is not confirmed because the species is phylogenetically and morphologically distinct. Thelopsis is recovered as polyphyletic, with T. melathelia being placed as sister species to Ramonia. The new combinations Thelopsis corticola (Coppins & P. James) Sanderson & Ertz comb. nov. and Ramonia melathelia (Nyl.) Ertz comb. nov. are introduced and a new species of Gyalecta, G. amsterdamensis Ertz, is described from Amsterdam and Saint-Paul Islands, characterized by a sterile thallus with discrete soralia. Petractis luetkemuelleri and P. nodispora are accommodated in the new genus Neopetractis, differing from the generic type (P. clausa) by having a different phylogenetic position and a different photobiont. Francisrosea bicolor Ertz & Sanderson gen. & sp. nov. is described for a sterile sorediate lichen somewhat similar to Opegrapha corticola but having an isolated phylogenetic position as sister to a clade including Gyalidea praetermissa and the genera Neopetractis and Ramonia. Gyalecta farlowii, G. nidarosiensis and G. carneola are placed in a molecular phylogeny for the first time. The taxonomic significance of morphological characters in Gyalectaceae is discussed.
Keywords: Arthoniales Gyalectales lichen multispory phylogeny
Programme: 1167
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. (2021). North Atlantic winter cyclones starve seabirds (Vol. 31). Bachelor's thesis, , .
Keywords: at-sea distribution cyclones energy expenditure GLS tracking seabird migration seascape ecology
Programme: 330,388
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. (2021). (Vol. 169). Bachelor's thesis, , .
Keywords: At-sea survey Frontal system Garbage patch Plastic litter Southern Indian Ocean
Programme: 109
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. (2021). Mercury in precipitated and surface snow at Dome C and a first estimate of mercury depositional fluxes during the Austral summer on the high Antarctic plateau (Vol. 262).
Keywords: Atmospheric conditions High resolution sampling Snow scavenging factor Snow sublimation
Programme: 1028
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Benjamin Pohl, Vincent Favier, Jonathan Wille, Danielle G Udy, Tessa R Vance, Julien Pergaud, Niels Dutrievoz, Juliette Blanchet, Christoph Kittel, Charles Amory, Gerhard Krinner, Francis Codron. (2021). Relationship Between Weather Regimes and Atmospheric Rivers in East Antarctica (Vol. 126).
Keywords: atmospheric rivers East Antarctica snowfall amounts temperature anomalies weather regimes
Programme: 411
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. (2021). Surface ocean microbiota determine cloud precursors (Vol. 11).
Abstract: One pathway by which the oceans influence climate is via the emission of sea spray that may subsequently influence cloud properties. Sea spray emissions are known to be dependent on atmospheric and oceanic physicochemical parameters, but the potential role of ocean biology on sea spray fluxes remains poorly characterized. Here we show a consistent significant relationship between seawater nanophytoplankton cell abundances and sea-spray derived Cloud Condensation Nuclei (CCN) number fluxes, generated using water from three different oceanic regions. This sensitivity of CCN number fluxes to ocean biology is currently unaccounted for in climate models yet our measurements indicate that it influences fluxes by more than one order of magnitude over the range of phytoplankton investigated.
Keywords: Atmospheric science Marine biology
Programme: 1187
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