Movement tactics of a mobile predator in a meta-ecosystem with fluctuating resources: the arctic fox in the High Arctic

Oikos ◽  
2016 ◽  
Vol 126 (7) ◽  
pp. 937-947 ◽  
Author(s):  
Sandra Lai ◽  
Joël Bêty ◽  
Dominique Berteaux
2019 ◽  
Author(s):  
Audrey Simon ◽  
Olivia Tardy ◽  
Amy Hurford ◽  
Nicolas Lecomte ◽  
Denise Bélanger ◽  
...  

Rabies is a major issue for human and animal health in the Arctic, yet little is known about its epidemiology. In particular, there is an ongoing debate regarding how Arctic rabies persists in its primary reservoir host, the Arctic fox (Vulpes lagopus), which exists in the ecosystem at very low population densities. To shed light on the mechanisms of rabies persistence in the Arctic, we built a susceptible–exposed–infectious–recovered (SEIR) epidemiological model of rabies virus transmission in an Arctic fox population interacting with red foxes (Vulpes vulpes), a rabies host that is increasingly present in the Arctic. The model suggests that rabies cannot be maintained in resource-poor areas of the Arctic, characterized by low Arctic fox density, even in the presence of continuous reintroduction of the virus by infected Arctic foxes from neighbouring regions. However, in populations of relatively high Arctic fox density, rabies persists under conditions of higher transmission rate, prolonged infectious period and for a broad range of incubation periods. Introducing the strong cyclical dynamics of Arctic prey availability makes simulated rabies outbreaks less regular but more intense, with an onset that does not neatly track peaks in Arctic fox density. Finally, interaction between Arctic and red foxes increases the frequency and/or the intensity of rabies outbreaks in the Arctic fox population. Our work suggests that disruption of prey cycles and increasing interactions between Arctic and red foxes due to climate change and northern development may significantly change the epidemiology of rabies across the Arctic.


Oikos ◽  
1998 ◽  
Vol 83 (3) ◽  
pp. 545 ◽  
Author(s):  
Magnus Tannerfeldt ◽  
Anders Angerbjörn ◽  
Anders Angerbjorn

Author(s):  
Larisa A. Pautova ◽  
Vladimir A. Silkin ◽  
Marina D. Kravchishina ◽  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova

The structure of the summer planktonic communities of the Northern part of the Barents sea in the first half of August 2017 were studied. In the sea-ice melting area, the average phytoplankton biomass producing upper 50-meter layer of water reached values levels of eutrophic waters (up to 2.1 g/m3). Phytoplankton was presented by diatoms of the genera Thalassiosira and Eucampia. Maximum biomass recorded at depths of 22–52 m, the absolute maximum biomass community (5,0 g/m3) marked on the horizon of 45 m (station 5558), located at the outlet of the deep trench Franz Victoria near the West coast of the archipelago Franz Josef Land. In ice-free waters, phytoplankton abundance was low, and the weighted average biomass (8.0 mg/m3 – 123.1 mg/m3) corresponded to oligotrophic waters and lower mesotrophic waters. In the upper layers of the water population abundance was dominated by small flagellates and picoplankton from, biomass – Arctic dinoflagellates (Gymnodinium spp.) and cold Atlantic complexes (Gyrodinium lachryma, Alexandrium tamarense, Dinophysis norvegica). The proportion of Atlantic species in phytoplankton reached 75%. The representatives of warm-water Atlantic complex (Emiliania huxleyi, Rhizosolenia hebetata f. semispina, Ceratium horridum) were recorded up to 80º N, as indicators of the penetration of warm Atlantic waters into the Arctic basin. The presence of oceanic Atlantic species as warm-water and cold systems in the high Arctic indicates the strengthening of processes of “atlantificacion” in the region.


2019 ◽  
Author(s):  
Heiko Bozem ◽  
Peter Hoor ◽  
Daniel Kunkel ◽  
Franziska Köllner ◽  
Johannes Schneider ◽  
...  

Abstract. The springtime composition of the Arctic lower troposphere is to a large extent controlled by transport of mid-latitude air masses into the Arctic, whereas during the summer precipitation and natural sources play the most important role. Within the Arctic region, there exists a transport barrier, known as the polar dome, which results from sloping isentropes. The polar dome, which varies in space and time, exhibits a strong influence on the transport of air masses from mid-latitudes, enhancing it during winter and inhibiting it during summer. Furthermore, a definition for the location of the polar dome boundary itself is quite sparse in the literature. We analyzed aircraft based trace gas measurements in the Arctic during two NETCARE airborne field camapigns (July 2014 and April 2015) with the Polar 6 aircraft of Alfred Wegener Institute Helmholtz Center for Polar and Marine Research (AWI), Bremerhaven, Germany, covering an area from Spitsbergen to Alaska (134° W to 17° W and 68° N to 83° N). For the spring (April 2015) and summer (July 2014) season we analyzed transport regimes of mid-latitude air masses travelling to the high Arctic based on CO and CO2 measurements as well as kinematic 10-day back trajectories. The dynamical isolation of the high Arctic lower troposphere caused by the transport barrier leads to gradients of chemical tracers reflecting different local chemical life times and sources and sinks. Particularly gradients of CO and CO2 allowed for a trace gas based definition of the polar dome boundary for the two measurement periods with pronounced seasonal differences. For both campaigns a transition zone rather than a sharp boundary was derived. For July 2014 the polar dome boundary was determined to be 73.5° N latitude and 299–303.5 K potential temperature, respectively. During April 2015 the polar dome boundary was on average located at 66–68.5° N and 283.5–287.5 K. Tracer-tracer scatter plots and probability density functions confirm different air mass properties inside and outside of the polar dome for the July 2014 and April 2015 data set. Using the tracer derived polar dome boundaries the analysis of aerosol data indicates secondary aerosol formation events in the clean summertime polar dome. Synoptic-scale weather systems frequently disturb this transport barrier and foster exchange between air masses from midlatitudes and polar regions. During the second phase of the NETCARE 2014 measurements a pronounced low pressure system south of Resolute Bay brought inflow from southern latitudes that pushed the polar dome northward and significantly affected trace gas mixing ratios in the measurement region. Mean CO mixing ratios increased from 77.9 ± 2.5 ppbv to 84.9 ± 4.7 ppbv from the first period to the second period. At the same time CO2 mixing ratios significantly dropped from 398.16 ± 1.01 ppmv to 393.81 ± 2.25 ppmv. We further analysed processes controlling the recent transport history of air masses within and outside the polar dome. Air masses within the spring time polar dome mainly experienced diabatic cooling while travelling over cold surfaces. In contrast air masses in the summertime polar dome were diabatically heated due to insolation. During both seasons air masses outside the polar dome slowly descended into the Arctic lower troposphere from above caused by radiative cooling. The ascent to the middle and upper troposphere mainly took place outside the Arctic, followed by a northward motion. Our results demonstrate the successful application of a tracer based diagnostic to determine the location of the polar dome boundary.


1989 ◽  
Vol 49 (1) ◽  
pp. 67-81 ◽  
Author(s):  
Páll Hersteinsson ◽  
Anders Angerbjörn ◽  
Karl Frafjord ◽  
Asko Kaikusalo

2011 ◽  
Vol 78 (2) ◽  
pp. 549-559 ◽  
Author(s):  
Thibault Varin ◽  
Connie Lovejoy ◽  
Anne D. Jungblut ◽  
Warwick F. Vincent ◽  
Jacques Corbeil

ABSTRACTPolar and alpine microbial communities experience a variety of environmental stresses, including perennial cold and freezing; however, knowledge of genomic responses to such conditions is still rudimentary. We analyzed the metagenomes of cyanobacterial mats from Arctic and Antarctic ice shelves, using high-throughput pyrosequencing to test the hypotheses that consortia from these extreme polar habitats were similar in terms of major phyla and subphyla and consequently in their potential responses to environmental stresses. Statistical comparisons of the protein-coding genes showed similarities between the mats from the two poles, with the majority of genes derived fromProteobacteriaandCyanobacteria; however, the relative proportions differed, with cyanobacterial genes more prevalent in the Antarctic mat metagenome. Other differences included a higher representation ofActinobacteriaandAlphaproteobacteriain the Arctic metagenomes, which may reflect the greater access to diasporas from both adjacent ice-free lands and the open ocean. Genes coding for functional responses to environmental stress (exopolysaccharides, cold shock proteins, and membrane modifications) were found in all of the metagenomes. However, in keeping with the greater exposure of the Arctic to long-range pollutants, sequences assigned to copper homeostasis genes were statistically (30%) more abundant in the Arctic samples. In contrast, more reads matching the sigma B genes were identified in the Antarctic mat, likely reflecting the more severe osmotic stress during freeze-up of the Antarctic ponds. This study underscores the presence of diverse mechanisms of adaptation to cold and other stresses in polar mats, consistent with the proportional representation of major bacterial groups.


2015 ◽  
Vol 502 ◽  
pp. 510-516 ◽  
Author(s):  
Kathrine Eggers Pedersen ◽  
Bjarne Styrishave ◽  
Christian Sonne ◽  
Rune Dietz ◽  
Bjørn Munro Jenssen

Polar Biology ◽  
2021 ◽  
Author(s):  
Peter S. Ungar ◽  
Blaire Van Valkenburgh ◽  
Alexandria S. Peterson ◽  
Aleksandr A. Sokolov ◽  
Natalia A. Sokolova ◽  
...  

Ocean Science ◽  
2014 ◽  
Vol 10 (6) ◽  
pp. 967-975 ◽  
Author(s):  
A. J. G. Nurser ◽  
S. Bacon

Abstract. The first (and second) baroclinic deformation (or Rossby) radii are presented north of ~60° N, focusing on deep basins and shelf seas in the high Arctic Ocean, the Nordic seas, Baffin Bay, Hudson Bay and the Canadian Arctic Archipelago, derived from climatological ocean data. In the high Arctic Ocean, the first Rossby radius increases from ~5 km in the Nansen Basin to ~15 km in the central Canadian Basin. In the shelf seas and elsewhere, values are low (1–7 km), reflecting weak density stratification, shallow water, or both. Seasonality strongly impacts the Rossby radius only in shallow seas, where winter homogenization of the water column can reduce it to below 1 km. Greater detail is seen in the output from an ice–ocean general circulation model, of higher resolution than the climatology. To assess the impact of secular variability, 10 years (2003–2012) of hydrographic stations along 150° W in the Beaufort Gyre are also analysed. The first-mode Rossby radius increases over this period by ~20%. Finally, we review the observed scales of Arctic Ocean eddies.


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