Seasonal change and microhabitat association of Arctic spider assemblages (Arachnida: Araneae) on Victoria Island (Nunavut, Canada)

2017 ◽  
Vol 149 (3) ◽  
pp. 357-371 ◽  
Author(s):  
Elyssa R. Cameron ◽  
Christopher M. Buddle
Keyword(s):  
Seasonal Change ◽  
Ecological Monitoring ◽  
High Arctic ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Active Season ◽  
The North ◽  
Arthropod Predators ◽  
Abundance And Diversity ◽  
Victoria Island

AbstractArctic ecosystems are characterised by a mosaic of distinct microhabitats, which play a key role in structuring biodiversity. Understanding species diversity in relation to these microhabitats, and how communities are structured seasonally, is imperative to properly conserve, monitor, and manage northern biodiversity. Spiders (Arachnida: Araneae) are dominant arthropod predators in the Arctic, yet the seasonal change in their communities in relation to microhabitat variation is relatively unknown. This research quantified how spider assemblages are structured seasonally and by microhabitat, near Cambridge Bay, Nunavut, Canada. In 2014, spiders were collected in 240 pan and pitfall traps placed in common microhabitat types (two wet and two dry) from 3 July to 11 August, the active season in the high Arctic. In total, 10 353 spiders from 22 species and four families were collected. Non-metric multidimensional scaling ordinations revealed that spider assemblages from wet habitats were distinct from those occurring in drier habitats, but that differences within each of those habitats were not evident. Abundance and diversity was highest in wet habitats and differed significantly from dry habitats; both these variables decreased seasonally. Spider assemblages in the north are structured strongly along moisture gradients, and such data informs planning for future ecological monitoring in the Arctic.

scholarly journals Dynamics of Ice-Island Motion Near the Coast of Axel Heiberg Island, Canadian High Arctic

1989 ◽  
Vol 12 ◽  
pp. 152-156 ◽  
Author(s):  
W.M. Sackinger ◽  
M.O. Jeffries ◽  
H. Tippens ◽  
F. Li ◽  
M. Lu
Keyword(s):  
Surface Wind ◽  
High Arctic ◽  
The Arctic ◽  
Movement Direction ◽  
Canadian High Arctic ◽  
North West ◽  
The North ◽  
Pack Ice ◽  
Axel Heiberg Island ◽  
Ice Force

The largest ice island presently known to exist in the Arctic Ocean has a mass of about 700 × 106 tonnes, an area of about 26 km2, and a mean thickness of 42.5 m. Known as Hobson’s Ice Island, this large ice feature has been tracked almost continuously since August 1983 with a succession of Argos buoys. In this paper, two particular ice-island movement episodes near the north-west coast of Axel Heiberg Island are described: 6–16 May 1986 and 14–21 June 1986. Each movement episode is analyzed in terms of the forces acting on the ice island, including wind shear, water drag, water shear, Coriolis force, sea-surface tilt, and pack-ice force. Ice-island movement is generally preceded by an offshore surface wind, and a threshold wind speed of 6 m s°1 appears to be necessary to initiate ice-island motion. An angle of 50° between surface wind and ice-island movement direction is noted during one episode. The pack-ice force, which appears to be the dominant arresting factor of ice-island motion for these two episodes, varies from 100° to 180° to the left of the ice-island velocity direction, depending upon whether the ice island is accelerating or decelerating.

scholarly journals Status and trends of terrestrial arthropod abundance and diversity in the North Atlantic region of the Arctic

AMBIO ◽  
2019 ◽  
Vol 49 (3) ◽  
pp. 718-731 ◽  
Author(s):  
Mark A. K. Gillespie ◽  
Matthias Alfredsson ◽  
Isabel C. Barrio ◽  
Joseph J. Bowden ◽  
Peter Convey ◽  
...  
Keyword(s):  
North Atlantic ◽  
The Arctic ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
The North ◽  
Status And Trends ◽  
The North Atlantic ◽  
Abundance And Diversity ◽  
Arthropod Abundance

scholarly journals Towards High-Resolution Land-Cover Classification of Greenland: A Case Study Covering Kobbefjord, Disko and Zackenberg

2021 ◽  
Vol 13 (18) ◽  
pp. 3559
Author(s):  
Daniel Alexander Rudd ◽  
Mojtaba Karami ◽  
Rasmus Fensholt
Keyword(s):  
Land Cover ◽  
Arctic Region ◽  
Ecological Monitoring ◽  
Land Cover Classification ◽  
Temporal Analysis ◽  
Google Earth ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Land Cover Maps ◽  
Sentinel 2

Mapping of the Arctic region is increasingly important in light of global warming as land cover maps can provide the foundation for upscaling of ecosystem properties and processes. To this end, satellite images provide an invaluable source of Earth observations to monitor land cover in areas that are otherwise difficult to access. With the continuous development of new satellites, it is important to optimize the existing maps for further monitoring of Arctic ecosystems. This study presents a scalable classification framework, producing novel 10 m resolution land cover maps for Kobbefjord, Disko, and Zackenberg in Greenland. Based on Sentinel-2, a digital elevation model, and Google Earth Engine (GEE), this framework classifies the areas into nine classes. A vegetation land cover classification for 2019 is achieved through a multi-temporal analysis based on 41 layers comprising phenology, spectral indices, and topographical features. Reference data (1164 field observations) were used to train a random forest classifier, achieving a cross-validation accuracy of 91.8%. The red-edge bands of Sentinel-2 data proved to be particularly well suited for mapping the fen vegetation class. The study presents land cover mapping in the three study areas with an unprecedented spatial resolution and can be extended via GEE for further ecological monitoring in Greenland.

The Early Exploration of Greenland

1991 ◽  
Vol 10 (2) ◽  
pp. 247-258
Author(s):  
Jørgen Taagholt
Keyword(s):  
Scientific Knowledge ◽  
Scientific Research ◽  
High Arctic ◽  
North Pole ◽  
The Arctic ◽  
Northwest Passage ◽  
The North ◽  
New Information ◽  
Early Exploration ◽  
Southwest Greenland

About 4000 years ago the first immigration of Inuit tribes explorated Greenland, and about 1000 years ago the Norsemen explorated southwest Greenland; and Icelandic sagas describe every-day life. The early search for the Northwest Passage years ago was followed by intensive whaling during 17th and 18th centuries. The connection between Greenland and Scandinavia was re-established by Hans Egede, who started his missionary and explorationary activity in 1721, whereafter polymaths from Denmark and other countries contributed to our scientific knowledge. Several attempts to reach the North Pole resulted in new information about the High Arctic Greenland, while local Inuit, such as Hans Hendrik, played an important role in several expeditions in the Arctic. The growing Danish and foreign scientific expeditions led to the Danish government establishing in 1878 established the Commission for Scientific Research in Greenland, whose mandate was to coordinate such research.

scholarly journals Tracking of Arctic terns Sterna paradisaea reveals longest animal migration

2010 ◽  
Vol 107 (5) ◽  
pp. 2078-2081 ◽  
Author(s):  
Carsten Egevang ◽  
Iain J. Stenhouse ◽  
Richard A. Phillips ◽  
Aevar Petersen ◽  
James W. Fox ◽  
...  
Keyword(s):  
High Arctic ◽  
The Arctic ◽  
Migration Routes ◽  
Long Distance ◽  
Seasonal Movement ◽  
The North ◽  
Breeding Populations ◽  
Flight Costs ◽  
Sterna Paradisaea ◽  
And Performance

The study of long-distance migration provides insights into the habits and performance of organisms at the limit of their physical abilities. The Arctic tern Sterna paradisaea is the epitome of such behavior; despite its small size (<125 g), banding recoveries and at-sea surveys suggest that its annual migration from boreal and high Arctic breeding grounds to the Southern Ocean may be the longest seasonal movement of any animal. Our tracking of 11 Arctic terns fitted with miniature (1.4-g) geolocators revealed that these birds do indeed travel huge distances (more than 80,000 km annually for some individuals). As well as confirming the location of the main wintering region, we also identified a previously unknown oceanic stopover area in the North Atlantic used by birds from at least two breeding populations (from Greenland and Iceland). Although birds from the same colony took one of two alternative southbound migration routes following the African or South American coast, all returned on a broadly similar, sigmoidal trajectory, crossing from east to west in the Atlantic in the region of the equatorial Intertropical Convergence Zone. Arctic terns clearly target regions of high marine productivity both as stopover and wintering areas, and exploit prevailing global wind systems to reduce flight costs on long-distance commutes.

Arctic Lower-Tropospheric Warm and Cold Extremes: Horizontal and Vertical Transport, Diabatic Processes, and Linkage to Synoptic Circulation Features

2020 ◽  
Vol 33 (3) ◽  
pp. 993-1016 ◽  
Author(s):  
Lukas Papritz
Keyword(s):  
North Atlantic ◽  
Temperature Anomaly ◽  
Storm Track ◽  
High Arctic ◽  
The Arctic ◽  
Air Masses ◽  
The North ◽  
Diabatic Processes ◽  
Synoptic Circulation ◽  
Cold Extremes

AbstractThe thermodynamic processes and synoptic circulation features driving lower-tropospheric temperature extremes in the high Arctic (>80°N) are investigated. Based on 10-day kinematic backward trajectories from the 5% most intense potential temperature anomalies, the contributions of horizontal and vertical transport, subsidence-induced warming, and diabatic processes to the generation of the Arctic temperature anomaly are quantified. Cold extremes are mainly the result of sustained radiative cooling due to a sheltering of the Arctic from meridional airmass exchanges. This is linked to a strengthening of the tropospheric polar vortex, a reduced frequency of high-latitude blocking, and in winter also a southward shift of the North Atlantic storm track. The temperature anomaly of 60% of wintertime extremely warm air masses (90% in summer) is due to transport from a potentially warmer region. Subsidence from the Arctic midtroposphere in blocking anticyclones is the most important warming process with the largest contribution in summer (70% of extremely warm air masses). In both seasons, poleward transport of already warm air masses contributes around 20% and is favored by a poleward shift of the North Atlantic storm track. Finally, about 40% of the air masses in winter are of an Arctic origin and experience diabatic heating by surface heat fluxes in marine cold air outbreaks. Our study emphasizes the importance of processes in the Arctic and the relevance of anomalous blocking—in winter in the Barents, Kara, and Laptev Seas and in summer in the high Arctic—for the formation of warm extremes.

The Grenville–Sveconorwegian orogen in the high Arctic

2012 ◽  
Vol 149 (5) ◽  
pp. 875-891 ◽  
Author(s):  
HENNING LORENZ ◽  
DAVID G. GEE ◽  
ALEXANDER N. LARIONOV ◽  
JAROSLAW MAJKA
Keyword(s):  
High Arctic ◽  
Detrital Zircons ◽  
The Arctic ◽  
Long Distance ◽  
Novaya Zemlya ◽  
The North ◽  
Long Distance Transport ◽  
Continental Shelves ◽  
Mountain Belts ◽  
Sveconorwegian Orogen

AbstractThroughout the high Arctic, from northern Canada (Pearya) to eastern Greenland, Svalbard, Franz Josef Land, Novaya Zemlya, Taimyr and Severnaya Zemlya and, at lower Arctic latitudes, in the Urals and the Scandinavian Caledonides, there is evidence of the Grenville–Sveconorwegian Orogen. The latest orogenic phase (c. 950 Ma) is well exposed in the Arctic, but only minor Mesoproterozoic fragments of this orogen occur on land. However, detrital zircons in Neoproterozoic and Palaeozoic successions provide unambiguous Mesoproterozoic to earliest Neoproterozoic (c. 950 Ma) signatures. This evidence strongly suggests that the Grenville–Sveconorwegian Orogen continues northwards from type areas in southeastern Canada and southwestern Scandinavia, via the North Atlantic margins to the high Arctic continental shelves. The widespread distribution of late Mesoproterozoic detrital zircons far to the north of the Grenville–Sveconorwegian type areas is usually explained in terms of long-distance transport (thousands of kilometres) of either sediments by river systems from source to sink, or of slices of lithosphere (terranes) moved on major transcurrent faults. Both of these interpretations involve much greater complexity than the hypothesis favoured here, the former involving recycling of the zircons from the strata of initial deposition into those of their final residence and the latter requiring a diversity of microcontinents. Neither explains either the fragmentary evidence for the presence of Grenville–Sveconorwegian terranes in the high Arctic, or the composition of the basement of the continental shelves. The presence of the Grenville–Sveconorwegian Orogen in the Arctic, mainly within the hinterland and margins of the Caledonides and Timanides, has profound implications not only for the reconstructions of the Rodinia supercontinent in early Neoproterozoic time, but also the origin of these Neoproterozoic and Palaeozoic mountain belts.

scholarly journals Abundance, habitat use and food consumption of seabirds in the high-Arctic fjord ecosystem

Polar Biology ◽  
2021 ◽  
Vol 44 (4) ◽  
pp. 739-750
Author(s):  
Lech Stempniewicz ◽  
Michał Goc ◽  
Marta Głuchowska ◽  
Dorota Kidawa ◽  
Jan Marcin Węsławski
Keyword(s):  
High Arctic ◽  
Pelagic Zone ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Rissa Tridactyla ◽  
Arctic Fjord ◽  
Main Components ◽  
And Function ◽  
Arctic Food Web ◽  
Induced Changes

AbstractTo monitor the rapid changes occurring in Arctic ecosystems and predict their direction, basic information about the current number and structure of the main components of these systems is necessary. Using boat-based surveys, we studied the numbers and distribution of seabirds foraging in Hornsund (SW Spitsbergen) during three summer seasons. The average number of seabirds foraging concurrently in the whole fjord was estimated at 28,000. Little Auks Alle alle were the most numerous, followed by Northern Fulmars Fulmarus glacialis, Brünnich’s Guillemots Uria lomvia and Black-legged Kittiwakes Rissa tridactyla. The pelagic zone was exploited by some 75% of the birds. Their density was the highest (> 400 ind. km−2) in the tidewater glacier bays, where kittiwakes were predominant, and the lowest in the coastal glacier bays. The seabirds in Hornsund daily consumed c. 12.7 tons of food, i.e. c. 0.2% of the summer mesozooplankton and fish standing stocks available in the fjord. This food consisted primarily of copepods, amphipods and molluscs (c. 70%), whereas fish made up < 15%. More than 50% of this biomass was ingested by pursuit divers, while surface feeders took c. 29% and benthophages c. 13%. About three-quarters of the food biomass was taken from the pelagic zone. This paper describes, for the first time in quantitative terms, the structure and function of a seabird community foraging in an Arctic fjord. It also provides a baseline for future studies on climate-induced changes in the importance of seabirds in the Arctic food web.

scholarly journals Snowfall and Oxygen-Isotope Variations off the North Coast of Ellesmere Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 195-199 ◽  
Author(s):  
Martin O. Jeffries ◽  
H. Roy Krouse
Keyword(s):  
Arctic Ocean ◽  
High Arctic ◽  
Geographic Region ◽  
Ellesmere Island ◽  
The Arctic ◽  
North Coast ◽  
Snow Pack ◽  
The North ◽  
Winter Snow ◽  
The Mean

AbstractSnow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean δ18O value of the snow-pack was -31.3˚/00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of δ18O variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The δ18O profiles show seasonal variations, with winter snow being more depleted in 18O than fall and spring snow. However, the δ18O profiles are dominated by a trend to higher δ18O values with increasing depth. This is attributed to a decrease in δ18O values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on δ values gives rise to a sharp discontinuity in the δ18O profiles and a bi-modal δ18O frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider δ18O range but does not significantly alter the mean δ18O value.

scholarly journals Birds of three worlds: moult migration to high Arctic expands a boreal-temperate flyway to a third biome

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Antti Piironen ◽  
Antti Paasivaara ◽  
Toni Laaksonen
Keyword(s):  
Bird Migration ◽  
High Arctic ◽  
The Arctic ◽  
Migratory Connectivity ◽  
Migration Routes ◽  
Arctic Ecosystems ◽  
Long Distance ◽  
Novaya Zemlya ◽  
Bean Goose ◽  
Moult Migration

Abstract Background Knowledge on migration patterns and flyways is a key for understanding the dynamics of migratory populations and evolution of migratory behaviour. Bird migration is usually considered to be movements between breeding and wintering areas, while less attention has been paid to other long-distance movements such as moult migration. Methods We use high-resolution satellite-tracking data from 58 taiga bean geese Anser fabalis fabalis from the years 2019–2020, to study their moult migration during breeding season. We show the moulting sites, estimate the migratory connectivity between the breeding and the moulting sites, and estimate the utilization distributions during moult. We reveal migration routes and compare the length and timing of migration between moult migrants and successful breeders. Results All satellite-tracked non-breeding and unsuccessfully breeding taiga bean geese migrated annually to the island of Novaya Zemlya in the high Arctic for wing moult, meaning that a large part of the population gathers at the moulting sites outside the breeding range annually for approximately three months. Migratory connectivity between breeding and moulting sites was very low (rm =  − 0.001, 95% CI − 0.1562–0.2897), indicating that individuals from different breeding grounds mix with each other on the moulting sites. Moult migrants began fall migration later in autumn than successful breeders, and their overall annual migration distance was over twofold compared to the successful breeders. Conclusions Regular moult migration makes the Arctic an equally relevant habitat for the taiga bean goose population as their boreal breeding and temperate wintering grounds, and links ecological communities in these biomes. Moult migration plays an important role in the movement patterns and spatio-temporal distribution of the population. Low migratory connectivity between breeding and moulting sites can potentially contribute to the gene flow within the population. Moult migration to the high Arctic exposes the population to the rapid impacts of global warming to Arctic ecosystems. Additionally, Novaya Zemlya holds radioactive contaminants from various sources, which might still pose a threat to moult migrants. Generally, these results show that moult migration may essentially contribute to the way we should consider bird migration and migratory flyways.

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