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Author Manuele Bazzichetto, François Massol, Marta Carboni, Jonathan Lenoir, Jonas J. Lembrechts, Rémi Joly, David Renault
Title Once upon a time in the far south: Influence of local drivers and functional traits on plant invasion in the harsh sub-Antarctic islands Type Journal
Year 2021 Publication Journal of Vegetation Science Abbreviated Journal
Volume 32 Issue (down) 4 Pages e13057
Keywords alien plants anthropogenic propagule pressure cold environments human disturbances plant invasiveness species distribution models topoclimate
Abstract Aim Here, we aim to: (a) investigate the local effect of environmental and anthropogenic factors on alien plant invasion in sub-Antarctic islands; and (b) explore whether and how functional traits affect alien species dependence on anthropogenic factors in these environments. Location Possession Island, Crozet archipelago (French sub-Antarctic islands). Methods Single-species distribution models were used to explore the effect of high-resolution topoclimatic and human-related variables on the occurrence of six alien plants colonizing French sub-Antarctic islands. Furthermore, plant responses to human-related variables and the effect of those variables in interaction with plant traits were analysed by means of a multi-species distribution model. This allowed identifying functional features mediating the influence of human activities on the occurrence probability of alien plant species. Results We observed two main invasion patterns: (a) species predicted to occur close to the introduction sites, whose occurrence probability appeared to be strongly affected by anthropogenic factors; and (b) species predicted to occur nearly everywhere on Possession Island, except in areas featuring particularly harsh climatic conditions. Differences in the influence of human-related variables on the occurrence of the alien species were mostly related to their life history, plant height and residence time, with perennial and low-statured species introduced earlier appearing less dependent on human-induced dispersal and disturbance. Conclusions We conclude that both topoclimatic and anthropogenic factors affect plant invasion on sub-Antarctic islands. Specifically, species predicted to occur close to their introduction sites appear much more dependent on human presence and activity, potentially due to the lack of key functional traits allowing them to spread successfully across Possession Island under the harsh sub-Antarctic climate. Yet, particularly severe abiotic conditions are a major constraint which equally limits the occurrence of all alien plants, irrespective of their dependence on anthropogenic factors.
Programme 136
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1654-1103 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8298
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Author Laurel Kaye, Shreyas Vissapragada, Maximilian N Günther, Suzanne Aigrain, Thomas Mikal-Evans, Eric L N Jensen, Hannu Parviainen, Francisco J Pozuelos, Lyu Abe, Jack S Acton, Abdelkrim Agabi, Douglas R Alves, David R Anderson, David J Armstrong, Khalid Barkaoui, Oscar Barragán, Björn Benneke, Patricia T Boyd, Rafael Brahm, Ivan Bruni, Edward M Bryant, Matthew R Burleigh, Sarah L Casewell, David Ciardi, Ryan Cloutier, Karen A Collins, Kevin I Collins, Dennis M Conti, Ian J M Crossfield, Nicolas Crouzet, Tansu Daylan, Diana Dragomir, Georgina Dransfield, Daniel Fabrycky, Michael Fausnaugh, Gábor Fuűrész, Tianjun Gan, Samuel Gill, Michaël Gillon, Michael R Goad, Varoujan Gorjian, Michael Greklek-McKeon, Natalia Guerrero, Tristan Guillot, Emmanuël Jehin, J S Jenkins, Monika Lendl, Jacob Kamler, Stephen R Kane, John F Kielkopf, Michelle Kunimoto, Wenceslas Marie-Sainte, James McCormac, Djamel Mékarnia, Farisa Y Morales, Maximiliano Moyano, Enric Palle, Vivien Parmentier, Howard M Relles, François-Xavier Schmider, Richard P Schwarz, S Seager, Alexis M S Smith, Thiam-Guan Tan, Jake Taylor, Amaury H M J Triaud, Joseph D Twicken, Stephane Udry, J I Vines, Gavin Wang, Peter J Wheatley, Joshua N Winn
Title Transit timings variations in the three-planet system: TOI-270 Type Journal
Year 2021 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 510 Issue (down) 4 Pages 5464-5485
Keywords
Abstract We present ground- and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered by TESS around a bright (K-mag = 8.25) M3V dwarf. The planets orbit near low-order mean-motion resonances (5:3 and 2:1) and are thus expected to exhibit large transit timing variations (TTVs). Following an extensive observing campaign using eight different observatories between 2018 and 2020, we now report a clear detection of TTVs for planets c and d, with amplitudes of ∼10 min and a super-period of ∼3 yr, as well as significantly refined estimates of the radii and mean orbital periods of all three planets. Dynamical modelling of the TTVs alone puts strong constraints on the mass ratio of planets c and d and on their eccentricities. When incorporating recently published constraints from radial velocity observations, we obtain masses of $M{\mathrm{b}}=1.48\pm 0.18\, M\oplus$, $M{\mathrm{c}}=6.20\pm 0.31\, M\oplus$, and $M{\mathrm{d}}=4.20\pm 0.16\, M\oplus$ for planets b, c, and d, respectively. We also detect small but significant eccentricities for all three planets : eb = 0.0167 ± 0.0084, ec = 0.0044 ± 0.0006, and ed = 0.0066 ± 0.0020. Our findings imply an Earth-like rocky composition for the inner planet, and Earth-like cores with an additional He/H2O atmosphere for the outer two. TOI-270 is now one of the best constrained systems of small transiting planets, and it remains an excellent target for atmospheric characterization.
Programme 1066
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8413
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Author Christophe Sauser, Karine Delord, Christophe Barbraud
Title Sea ice and local weather affect reproductive phenology of a polar seabird with breeding consequences Type Journal
Year 2021 Publication Ornithological Applications Abbreviated Journal
Volume 123 Issue (down) 4 Pages duab032
Keywords
Abstract Breeding at the right time is essential for animals living in seasonal environments to ensure that energy requirements for reproduction, especially the nutritional needs for rearing offspring, coincide with peak food availability. Climate change is likely to cause modifications in the timing of maximum food availability, and organisms living in polar environments where the breeding period is heavily contracted may be particularly affected. Here we used a 26-year dataset to study the phenological response of a pagophilic species, the Snow Petrel (Pagodroma nivea), to climate change and its demographic impact. First, we investigated the trends and relationships between climate variables and hatching dates measured in three neighboring colonies. In a second step, we examined the impact of the hatching date and environmental covariates on the fledging probability. Our results showed that sea ice, a climate-related variable, showed a positive temporal trend. We found that hatching date was delayed when sea ice concentration was greater and local weather conditions were worse (i.e., increase in the number of windy days or the number of snow days). Hatching date had a negative effect on fledging probability, and fledging probability showed a bell-shaped temporal trend. We suggest that Snow Petrels can delay breeding phenology in response to environmental conditions. However, this plasticity may be limited as fledging success decreased with delayed hatching, potentially making the Snow Petrel vulnerable to a mismatch between resource availability and nutritional needs.• Timing of reproduction is essential for wild animals to ensure that reproductive requirements, including nutritional requirements for rearing offspring, coincide with peak food availability.• Climate change can affect the timing of food availability, and organisms living in polar environments, where the timing of reproduction is highly contracted, may be particularly affected. We analyzed whether a sea ice dependent species, the Snow Petrel (Pagodroma nivea), would breed earlier or later in response to climate change, as measured by changes in sea ice and weather conditions. Then, we looked at the impact that a shift in reproduction might have on breeding success.• Our results showed that hatching date was delayed when sea ice increased and local weather conditions worsened. Secondly, we showed that the shift in hatching date had a negative effect on breeding success.• Snow Petrels adjusted the onset of reproduction in response to environmental changes. However, this adjustment had limits since late reproduction likely leads to a mismatch between the availability of resources and nutritional needs, and thus to a decrease the breeding success.
Programme 109
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0010-5422 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8431
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Author Samuel Veilleux, Armelle Decaulne, Najat Bhiry
Title Snow cornice and snow avalanche monitoring using automatic time lapse cameras in Tasiapik Valley, Nunavik (Québec) during the winter of 2017–2018 Type Journal
Year 2021 Publication Arctic Science Abbreviated Journal
Volume 7 Issue (down) 4 Pages 798-812
Keywords
Abstract A series of automatic time-lapse cameras installed along the southwestern side of Tasiapik Valley, near the village of Umiujaq, Nunavik (northern Québec) documented several departure modes and types of snow involved in snow avalanches during winter 2017–2018. These included cornice–avalanche dynamics, slab and loose snow avalanches, and clean and dirty snow avalanches. At the top of the selected slope, a camera monitored the development of a snow cornice beginning in November 2017, detecting multiple cornice failures over the winter and spring. The track and deposition area of the runout paths were monitored from two cameras downslope, revealing the concomitance of snow–cornice fall and snow avalanche triggering. Snow avalanche activity remained relatively infrequent until the end of May 2018. Spring snow avalanche activity is characterized by wet and dirty snow avalanches carrying debris to the foot of the slope and by runout zones located near the road along the slope.
Programme 1148
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Area Expedition Conference
Notes Approved yes
Call Number Serial 8461
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Author Christian Zdanowicz, Jean-Charles Gallet, Mats P. Björkman, Catherine Larose, Thomas Schuler, Bartłomiej Luks, Krystyna Koziol, Andrea Spolaor, Elena Barbaro, Tõnu Martma, Ward van Pelt, Ulla Wideqvist, Johan Ström
Title Elemental and water-insoluble organic carbon in Svalbard snow: a synthesis of observations during 2007–2018 Type Journal
Year 2021 Publication Atmospheric Chemistry and Physics Abbreviated Journal
Volume 21 Issue (down) 4 Pages 3035-3057
Keywords
Abstract Light-absorbing carbonaceous aerosols emitted by biomass or fossil fuel combustion can contribute to amplifying Arctic climate warming by lowering the albedo of snow. The Svalbard archipelago, being near to Europe and Russia, is particularly affected by these pollutants, and improved knowledge of their distribution in snow is needed to assess their impact. Here we present and synthesize new data obtained on Svalbard between 2007 and 2018, comprising measurements of elemental (EC) and water-insoluble organic carbon (WIOC) in snow from 37 separate sites. We used these data, combined with meteorological data and snowpack modeling, to investigate the variability of EC and WIOC deposition in Svalbard snow across latitude, longitude, elevation and time. Overall, EC concentrations (CsnowEC) ranged from <1.0 to 266.6 ng g−1, while WIOC concentrations (CsnowWIOC) ranged from <1 to 9426 ng g−1, with the highest values observed near Ny-Ålesund. Calculated snowpack loadings (LsnowEC, LsnowWIOC) on glaciers surveyed in spring 2016 were 0.1 to 2.6 mg m−2 and 2 to 173 mg m−2, respectively. The median CsnowEC and the LsnowEC on those glaciers were close to or lower than those found in earlier (2007–2009), comparable surveys. Both LsnowEC and LsnowWIOC increased with elevation and snow accumulation, with dry deposition likely playing a minor role. Estimated area-averaged snowpack loads across Svalbard were 1.1 mg EC m−2 and 38.3 mg WIOC m−2 for the 2015–2016 winter. An ∼11-year long dataset of spring surface snow measurements from the central Brøgger Peninsula was used to quantify the interannual variability of EC and WIOC deposition in snow. In most years, CsnowEC and CsnowWIOC at Ny-Ålesund (50 m a.s.l.) were 2–5 times higher than on the nearby Austre Brøggerbreen glacier (456 m a.s.l.), and the median EC/WIOC in Ny-Ålesund was 6 times higher, suggesting a possible influence of local EC emission from Ny-Ålesund. While no long-term trends between 2011 and 2018 were found, CsnowEC and CsnowWIOC showed synchronous variations at Ny-Ålesund and Austre Brøggerbreen. When compared with data from other circum-Arctic sites obtained by comparable methods, the median CsnowEC on Svalbard falls between that found in central Greenland (lowest) and those in continental sectors of European Arctic (northern Scandinavia, Russia and Siberia; highest), which is consistent with large-scale patterns of BC in snow reported by surveys based on other methods.
Programme 1192
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1680-7316 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8604
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Author Elena Barbaro, Krystyna Koziol, Mats P. Björkman, Carmen P. Vega, Christian Zdanowicz, Tonu Martma, Jean-Charles Gallet, Daniel Kępski, Catherine Larose, Bartłomiej Luks, Florian Tolle, Thomas V. Schuler, Aleksander Uszczyk, Andrea Spolaor
Title Measurement report: Spatial variations in ionic chemistry and water-stable isotopes in the snowpack on glaciers across Svalbard during the 2015–2016 snow accumulation season Type Journal
Year 2021 Publication Atmospheric Chemistry and Physics Abbreviated Journal
Volume 21 Issue (down) 4 Pages 3163-3180
Keywords
Abstract The Svalbard archipelago, located at the Arctic sea-ice edge between 74 and 81∘ N, is ∼60 % covered by glaciers. The region experiences rapid variations in atmospheric flow during the snow season (from late September to May) and can be affected by air advected from both lower and higher latitudes, which likely impact the chemical composition of snowfall. While long-term changes in Svalbard snow chemistry have been documented in ice cores drilled from two high-elevation glaciers, the spatial variability of the snowpack composition across Svalbard is comparatively poorly understood. Here, we report the results of the most comprehensive seasonal snow chemistry survey to date, carried out in April 2016 across 22 sites on seven glaciers across the archipelago. At each glacier, three snowpits were sampled along the altitudinal profiles and the collected samples were analysed for major ions (Ca2+, K+, Na+, Mg2+, NH4+, SO42-, Br−, Cl−, and NO3-) and stable water isotopes (δ18O, δ2H). The main aims were to investigate the natural and anthropogenic processes influencing the snowpack and to better understand the influence of atmospheric aerosol transport and deposition patterns on the snow chemical composition. The snow deposited in the southern region of Svalbard is characterized by the highest total ionic loads, mainly attributed to sea-salt particles. Both NO3- and NH4+ in the seasonal snowpack reflect secondary aerosol formation and post-depositional changes, resulting in very different spatial deposition patterns: NO3- has its highest loading in north-western Spitsbergen and NH4+ in the south-west. The Br− enrichment in snow is highest in north-eastern glacier sites closest to areas of extensive sea-ice coverage. Spatial correlation patterns between Na+ and δ18O suggest that the influence of long-range transport of aerosols on snow chemistry is proportionally greater above 600–700 m a.s.l.
Programme 1192
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1680-7316 ISBN 1680-7316 Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8608
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Author Natasha Roy, James Woollett, Najat Bhiry, Isabel Lemus-Lauzon, Ann Delwaide, Dominique Marguerie
Title Anthropogenic and climate impacts on subarctic forests in the Nain region, Nunatsiavut: Dendroecological and historical approaches Type Journal
Year 2021 Publication Écoscience Abbreviated Journal
Volume 28 Issue (down) 3-4 Pages 361-376
Keywords approches historiques croissance démographique Dendrochronologie Dendrochronology détente de croissance radiale growth release historical approaches Nain Nunatsiavut population growth
Abstract Several recent dendrochronological, macrofossil and palynological studies have surveyed modern spruce forests at multiple locations in the Nain region of coastal Nunatsiavut (north-central Labrador) in order to reconstruct past forest composition, growth rates, species diversity and harvesting patterns. The present paper synthesizes original and previously collected data to evaluate the extent to which the dynamics of the region’s spruce forests over the past five centuries have been related to anthropogenic impacts. In three key case studies, Picea growth release events demonstrate multiple isolated forest disturbances prior to the late 19th century. In general, these events correspond to the local human settlement history rather than to regional climatic trends, suggesting that ongoing human impacts on the forest extend as far back as the 17th century. Disturbance regimes accelerated by ca 1875 and afterward in all of the study sites. This increase in forest disturbance corresponds to increased demands for wood triggered by socio-economic changes experienced by the region’s Inuit and Settler communities. Ongoing surveys demonstrate the presence of markers of human exploitation of forests throughout the study region, and especially in coastal locations, suggesting that anthropogenic impacts are in fact generalised and not limited to specific areas of recent settlement.
Programme 1080
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1195-6860 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8251
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Author Charlène Gémard, Thierry Aubin, Eliette L. Reboud, Francesco Bonadonna
Title Call rate, fundamental frequency, and syntax determine male-call attractiveness in blue petrels Halobaena caerulea Type Journal
Year 2021 Publication Behavioral Ecology and Sociobiology Abbreviated Journal
Volume 75 Issue (down) 3 Pages 55
Keywords
Abstract In blue petrels (Halobaena caerulea), females are supposed to be particularly choosy and mate choice can take a couple of years. In these lifelong monogamous seabirds, choosing a good mate is crucial and has a strong influence on their fitness. Due to their nocturnal habits, the absence of sexual dimorphism, and the physical barrier between males calling from their burrow and females flying above the colony, vocal signals seem to be one of the main channels for males to communicate with potential mates. In a previous study, we investigated whether acoustic parameters of male calls carry information about morphological characteristics that might be indicators of males’ qualities. Here, we experimentally test whether these acoustic parameters linked to male characteristics are actually attractive to females. To do so, we played back modified calls of males to females in a colony of blue petrels of the Kerguelen archipelago. We found that flying females were more attracted by high-pitched calls, and by calls broadcasted at a high call rate. Previous studies showed a relationship between pitch and bill depth and length. In filter-feeding birds, such as blue petrels, bill morphology influences feeding efficiency. A high call rate is an indicator of sexual motivation and makes the caller easier to locate by potential mates and predators in the hubbub of the colony. We thus hypothesized that producing frequent high-pitched calls appeared to be preferable for a conspicuous sexual signaling although it may increase predation risks.
Programme 354
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ISSN 1432-0762 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7055
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Author Steven Franke, Daniela Jansen, Sebastian Beyer, Niklas Neckel, Tobias Binder, John Paden, Olaf Eisen
Title Complex Basal Conditions and Their Influence on Ice Flow at the Onset of the Northeast Greenland Ice Stream Type Journal
Year 2021 Publication Journal of Geophysical Research: Earth Surface Abbreviated Journal
Volume 126 Issue (down) 3 Pages e2020JF005689
Keywords basal roughness bed conditions Greenland Ice Sheet ice stream Northeast Greenland Ice Stream radio-echo sounding
Abstract Abstract The ice stream geometry and large ice surface velocities at the onset region of the Northeast Greenland Ice Stream (NEGIS) are not yet well reproduced by ice sheet models. The quantification of basal sliding and a parametrization of basal conditions remains a major gap. In this study, we assess the basal conditions of the onset region of the NEGIS in a systematic analysis of airborne ultra-wideband radar data. We evaluate basal roughness and basal return echoes in the context of the current ice stream geometry and ice surface velocity. We observe a change from a smooth to a rougher bed where the ice stream widens, and a distinct roughness anisotropy, indicating a preferred orientation of subglacial structures. In the upstream region, the excess ice mass flux through the shear margins is evacuated by ice flow acceleration and along-flow stretching of the ice. At the downstream part, the generally rougher bed topography correlates with a decrease in flow acceleration and lateral variations in ice surface velocity. Together with basal water routing pathways, this hints to two different zones in this part of the NEGIS: the upstream region collecting water, with a reduced basal traction, and downstream, where the ice stream is slowing down and is widening on a rougher bed, with a distribution of basal water toward the shear margins. Our findings support the hypothesis that the NEGIS is strongly interconnected to the subglacial water system in its onset region, but also to the subglacial substrate and morphology.
Programme 1180
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ISSN 2169-9003 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7272
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Author Karine Delord, Cédric Cotté, Pascal Terray, Charles-André Bost, Henri Weimerskirch, Christophe Barbraud
Title Factors affecting adult body condition in the endangered northern rockhopper penguin Type Journal
Year 2021 Publication Marine Biology Abbreviated Journal
Volume 168 Issue (down) 3 Pages 27
Keywords
Abstract Understanding the factors that drive the dynamics of populations of long‐lived species presents a unique challenge for conservation management. Here, we investigated long-term change in the body condition of adult northern rockhopper penguins Eudyptes moseleyi at Amsterdam Island, southern Indian Ocean, which hosts 5–10% of the global population of this endangered species. Analysis of a long‐term dataset (1994–2016), concurrent to the population's rapid decline, revealed no trend in adult northern rockhopper penguin body condition over time at the stages considered in this study, i.e. breeding and moulting. However, body condition varied between years and sexes and part of this variation was explained by environmental factors. Males were on average in better condition than females whatever the stage and individuals on average were in better condition during the moulting compared to the breeding period. The environmental conditions [sea surface temperature anomaly (SSTa), Subtropical Indian Ocean Dipole (SIOD) and Southern Annular Mode (SAM)] appeared to impact non-linearly the body condition. Overall, females were in better condition for negative values of SAM, SIOD and SSTa. The body condition of males exhibited similar but less complex and more significant patterns, with decreasing body condition for increasing SAM, SIOD and SSTa. The absence of long-term trends in male and female body condition suggests that the very low reproductive output and declining population since 1997 is probably not the result of environmental conditions during pre-breeding and pre-moult and necessitates further research into possible drivers during the breeding season.
Programme 109,394
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Corporate Author Thesis Bachelor's thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-1793 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7792
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