|
|
Renault D., Ouisse T., Laparie M. (2015). Metabolomic responses to thermal acclimation in a subpolar carabid beetle currently invading sub-Antarctic islands. 6th International Symposium on the Environmental Physiology of Ectotherms and Plant, Aahrus, Denmark, 03-06/08/2015.
|
|
|
|
Domine F, Barrere M, Sarrazin D, Morin S, Arnaud L, . (2015). Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra
. TC, 9(3), 1265–1276.
Abstract: The effective thermal conductivity of snow, keff, is a critical variable which determines the temperature gradient in the snowpack and heat exchanges between the ground and the atmosphere through the snow. Its accurate knowledge is therefore required to simulate snow metamorphism, the ground thermal regime, permafrost stability, nutrient recycling and vegetation growth. Yet, few data are available on the seasonal evolution of snow thermal conductivity in the Arctic. We have deployed heated needle probes on low-Arctic shrub tundra near Umiujaq, Quebec, (N56340; W76290) and monitored automatically the evolution of keff for two consecutive winters, 2012–2013 and 2013–2014, at four heights in the snowpack. Shrubs are 20 cm high dwarf birch. Here, we develop an algorithm for the automatic determination of keff from the heating curves and obtain 404 keff values. We evaluate possible errors and biases associated with the use of the heated needles. The time evolution of keff is very different for both winters. This is explained by comparing the meteorological conditions in both winters, which induced different conditions for snow metamorphism. In particular, important melting events in the second year increased snow hardness, impeding subsequent densification and increase in thermal conductivity.We conclude that shrubs have very important impacts on snow physical evolution: (1) shrubs absorb light and facilitate snow melt under intense radiation; (2) the dense twig network of dwarf birch prevent snow compaction, and therefore keff increase; (3) the low density depth hoar that forms within shrubs collapsed in late winter, leaving a void that was not filled by snow.
Programme: 1042
|
|
|
|
Labarrere B., Prinzing A., Chesneau E. & Hennion F. (2015). Polyamine variation across natural gradients and influence on plant development in subantarctic plant species.
2015 Society for Experimental Biology Annual Meeting, Prague, Czech Republic, 30th June- 03rd July..
Abstract: Metabolites are involved in plant development and hence play an important role in adjustment to climate change. Polyamines are a class of metabolites at the interface between environment and growth control in plants. However, there is still much uncertainty to what extent polyamines influence plant development in nature. Also, there is evidence that polyamines help plants to sustain stressful environmental conditions. However, the roles of polyamines for plants to sustain stress have been studied in model species or under single stresses and we don’t know whether results are extensible to other species and combined stresses found in the field.
Plants in Iles Kerguelen are adapted to conditions including low temperatures and abundant rainfall. However, Iles Kerguelen are subject to rapid and intense climate change such as enhanced temperature and decreased rainfall. These changes are expected to increase stress in plants, especially in wetlands.
We study three Ranunculus species from Kerguelen wetlands across natural environmental gradients and ask: (i) is polyamine composition determined by environment in the field? (ii) is polyamine response to a given environmental gradient consistent across species? (iii) how is polyamine composition related to plant development ? (iv) do these field observations match with known polyamine roles in response to stress and growth control?
Results show that polyamine composition varies across environmental gradients. However, relationship between polyamine composition and environment depends on both species and type of gradient. We show a relationship between polyamines and plant development. However, polyamines are related with different morphological characteristics depending on species.
Programme: 1116
|
|
|
|
Pansu Johan, Winkworth Richard C, Hennion Françoise, Gielly Ludovic, Taberlet Pierre, Choler Philippe, . (2015). Long-lasting modification of soil fungal diversity associated with the introduction of rabbits to a remote sub-Antarctic archipelago.
. Biol. Lett., 11(9), 20150408.
Abstract: During the late nineteenth century, Europeans introduced rabbits to many of the sub-Antarctic islands, environments that prior to this had been devoid of mammalian herbivores. The impacts of rabbits on indigenous ecosystems are well studied; notably, they cause dramatic changes in plant communities and promote soil erosion. However, the responses of fungal communities to such biotic disturbances remain unexplored. We used metabarcoding of soil extracellular DNA to assess the diversity of plant and fungal communities at sites on the sub-Antarctic Kerguelen Islands with contrasting histories of disturbance by rabbits. Our results suggest that on these islands, the simplification of plant communities and increased erosion resulting from the introduction of rabbits have driven compositional changes, including diversity reductions, in indigenous soil fungal communities. Moreover, there is no indication of recovery at sites from which rabbits were removed 20 years ago. These results imply that introduced herbivores have long-lasting and multifaceted effects on fungal biodiversity as well as highlight the low resiliency of sub-Antarctic ecosystems.
Programme: 136,1116
|
|
|
|
A. Stier, Q. Schull, V. Viblanc, D. Roussel, J.-P. Robin, P. Bize & F. Criscuolo . (2015). Thermogenesis, Fasting and Oxidative Stress: new insights from model and non-model animals. Conférence invitée au 9th International Congress of Comparative Physiology and Biochemistry, August 2015 (Krakow, Poland)..
|
|
|
|
V. A. Viblanc, Q. Schull, F. Stephen Dobson P. Bize & J-P. Robin. (2015). Advertising quality: condition-dependent signals in a monomorphic seabird, the king penguin (Aptenodytes patagonicus). 10th Conference of the European Ornithological Union, 24-28 August 2015, Badajoz (Spain), Conférence invitée au Symposium S11 : Mediators of individual quality in birds organisé par P. Bize & J-P. Robin dans le cadre de ce congrès.
|
|
|
|
Q. Schull, V. A. Viblanc, A. Stier, L. Durand, E. Lefol, P. Bize & J-P. Robin. (2015). Sexual selection and individual quality: do parental colour ornaments predict chick growth in monogamous King Penguins Aptenodytes patagonicus? 10th Conference of the European Ornithological Union, 24-28 August 2015, Badajoz (Spain).
|
|
|
|
Q. Schull., F. S. Dobson, A. Stier, F. Criscuolo, E. Lefol, H. Saadaoui, J-P. Robin, P. Bize, V. A. Viblanc. (2015). Sexual selection and individual quality: condition-dependent signals in a monomorphic seabird, the king penguin (Aptenodytes patagonicus). 11éme meeting « ECOLOGY AND BEHAVIOUR » : 18-21 Mai, Toulouse, FRANCE.
|
|
|
|
K.-L. Klein, N. Agueda, R. Bütikofer. (2015). On the origin of relativistic solar particle events: interplanetary transport modelling and radio emission (34th Internat Cosmic Ray Conference, The Hague).
Abstract: The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how these particles are accelerated is still controversial. The candidate processes are related to magnetic reconnection in a flare or a coronal mass ejection (CME), and to the shock wave driven by a fast CME. We search for observational indications on the acceleration site, using the relative timing of radio emissions in the corona and of relativistic protons at the Earth. We model the particle transport under the effects of focussing by an average Archimedean magnetic field and of scattering by its fluctuations, and use radio time profiles as injection functions. The predicted time profiles of the intensity and anisotropy of relativistic protons at 1 AU during the 20 Jan 2005 event are compared with neutron monitor observations. We compare the results with other events and discuss the nature of the prompt and delayed proton releases that have been identified in neutron monitor recordings of relativistic solar particle events.
Programme: 227
|
|
|
|
Q. Schull., V. A. Viblanc., F. S. Dobson., A. Stier., F. Criscuolo., E. Lefol., H. Saadaoui., P. Bize.4, J.-P. Robin. (2015). Sexual selection and individual quality in the king penguin (Aptenodytes patagonicus). Colloque des 11 èmes journées du CNFRA, Rennes (France).
|
|
