Ellef Ringnes Research Articles

Critical loads of acidity and exceedances for 1138 lakes and ponds in the Canadian Arctic

Sulphur emissions associated with increased anthropogenic activity, such as resource extraction and marine shipping, may lead to the acidification of aquatic freshwater systems in the Arctic. In the current study, acid sensitivity (based on a critical load (CL(Ac)) approach) of 1138 lakes and ponds in the Canadian Arctic was quantified using the Steady-State Water Chemistry (SSWC) model. Ecosystem protection was based on an Acid Neutralising Capacity limit (ANClimit) for Arctic Char. Acidification risk was estimated under modelled sulphur deposition for the year 2010 (two scenarios). Overall, surface water CL(Ac) values for the Canadian Arctic were low (median = 35.8 meq·m−2·yr−1, mean = 96.3 meq·m−2·yr−1), with approximately 40% (n = 455) of sites estimated to be sensitive to acidification (CL(Ac) < 20 meq·m−2·yr−1). Higher CL(Ac) values were found in Yukon (434.5 meq·m−2·yr−1, n = 40), Ellesmere Is. (262.2 meq·m−2·yr−1, n = 143), and Southampton Is. (251.5 meq·m−2·yr−1, n = 35), while lower CL(Ac) values were found in Melville Is. (5.5 meq·m−2·yr−1, n = 48), Banks Is. (18.4 meq·m−2·yr−1, n = 45), and Bylot Is. (20.4 meq·m−2·yr−1, n = 36). Under modelled deposition for 2010, 12–12.5% (n = 136–142) of all sites were exceeded. The highest proportion of exceeded sites were observed in Ellef Ringnes Is. (48–60%; n = 12–15), Melville Is. (38–44%; n = 18–21), and Northwest Territories (24–26%; n = 23–26).

The Indefatigable Mary R. Dawson: Arctic Pioneer

Abstract Between 1973 and 2002, Mary Dawson and team spent 11 field seasons searching for vertebrate fossils on Ellesmere, Axel Heiberg, Devon, Ellef Ringnes, Bylot, and Banks Islands in Canada's Arctic Archipelago. Their pioneering efforts resulted in one of the greatest discoveries in vertebrate paleontology of the twentieth century—the first, and best, record of Paleogene terrestrial vertebrates from within the Arctic Circle. Here we provide a history of the field research and discoveries by Dawson and collaborators in the Canadian High Arctic. Discovery of Eocene vertebrate faunas in the Eureka Sound Group on Ellesmere and Axel Heiberg Islands supports the former existence of a high-latitude land connection between Europe and North America, provides insight into the origin of certain mammalian taxa such as microparamyine rodents, and yields evidence for a warm, temperate High Arctic climate at that time. Moving up in the section, Dawson's discoveries in Haughton Astrobleme on Devon Island include the ...

Plant communities and plant production in the western Queen Elizabeth Islands

A study of soils, plant communities, and net annual plant production was conducted with 41 stands at 3 sites on 3 arctic islands. Twelve additional sites were studied in less detail on Ellef Ringnes, King Christian and Melville islands and on four other islands. Through polar ordination five groupings were recognized. Alopecurus and Puccinellia barrens on sand to silty soils and on silty soils, high in sodium salts respectively. Species richness averaged 2.6 ± 2.0 and total plant cover 6.8 ± 2.7%. The Phippsia barrens occur on sheet eroded surfaces and in gulleys with deep winter snow. Species richness was 9.8 ± 5.0 and total plant cover 14.8 ± 9.6%. The graminoid steppes on sandy soils averaged 7.6 ± 2.4 species and total plant cover 40.0 ± 2.8%. Eight stands were dominated by moss‐graminoids, mostly on loam soils. Species richness was 24.9 ± 3.4 and total plant cover 77.7 ± 16.1%. Plant producion was 8.0 g m−2 in a Puccinellia barren and 9.4 g m−2 in a Luzula confusa graminoid steppe. Net annual production ranged from 18.8 to 58.7 in 6 other stands. The 13 stands within the cryptogam‐herb community complex occur on sandy loam to clay‐loam soils. Species richness averaged 26.3 ± 6.2 and total plant cover 61.2 ± 24.7%.Mosses and lichens play a significant role in the establishment and maintenance of communities with a greater species richness and plant production of vascular plant species. The ability of mosses to hold moisture and the presence of limited bluegreen algae that fix nitrogen appear essential to the maintenance of greater species richness, plant cover and plant production compared with the barren polar deserts that are often nearby.

PARASITIC FUNGI OF THE QUEEN ELIZABETH ISLANDS

Fifty-six species, subspecies, and varieties of parasites are recorded from 23 locations, most from Isachsen in Ellef Ringnes I., Jacobsen-McGill Base in western Axel Heiberg I., and Hazen Camp in northern Ellesmere I. Previously published reports are assembled. Climatology and biogeography, as they relate to the fungi, are briefly discussed. Puccinia poae-nemoralis ssp. hyparctica Savile, Ustilentyloma pleuropogonis Savile (sp. et gen. nov., Ustilaginaceae), and Mycosphaerella oxyriae Savile are named. Clasterosporium caricinum and Columnophora rhytismatis are newly reported from the arctic.