CGRG Bibliography of Canadian Geomorphology
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Author : Antoniades, D.; Douglas, M.S.V.; and Smol, J.P.
Date : 2000.
Title : Diatom autecology and paleolimnology of Ellesmere, Ellef Ringnes and Prince Patrick Islands, Canadian High Arctic.
Publication : 8th International Paleolimnology Symposium, August 20 to August 24, 2000. Queen's University, Kingston, Ontario
Issue :
Page(s) :
Abstract
The High Arctic is thought to be a bellwether of environmental change, since it is a region more sensitive to changing environments than lower latitude systems. In assessing the significance of modern environmental change, knowledge of baseline conditions and the natural variability of systems is necessary in order to understand if current changes are within normal ranges for the High Arctic. Proxy reconstruction methods such as paleolimnology are invaluable due to their ability to reliably infer past conditions. Paleolimnological models using diatom-based transfer functions are now being developed and used in an attempt to provide these missing High Arctic data sets. This study is part of a larger database documenting the distribution of diatoms in the High Arctic. We are developing regional calibrations of diatoms from three high arctic sites in order to quantify the autecology of diatoms from extreme environments. Samples have been collected from Alert, northern Ellesmere Island (80°30'N, 60°20'W), Isachsen, Ellef Ringnes Island (78°47'N, 103°32'W) and Mould Bay, Prince Patrick Island (76°14'N, 119°20'W). The annual daily mean temperature ranges from -17.7 to -19.0°C, and annual precipitation ranges from 104 to 162 mm/ year. As is the case across much of the High Arctic, the sampled lakes and ponds were oligotrophic in nature. pH was affected by local geology and ranged from 5.2 to 9.1. Among most trace metals and ions, values were typical compared with those found in other arctic and high arctic studies. However, nutrients were generally at lower levels in the Alert region than at other arctic sites, including dissolved organic carbon (DOC), particulate nitrogen, and phosphorus. Higher DOC values were observed at the Mould Bay sites, likely due to much lusher vegetation here compared to our other regions. Nutrient levels were also highest at Mould Bay, partially reflecting the vegetation, but also the high abundance of animals and associated droppings. temporal and spatial A benthic diatom assemblage comprising over 400 diatom taxa has been identified across all three sites. Achnanthes minutissima, Nitzschia perminuta, and Navicula cryptotenella were the most common diatoms in the Alert area. In the Isachsen region, enumeration is ongoing, but qualitatively, Stauroneis anceps and Fragilaria capucina are the most common diatoms. Mould Bay has a varied diatom assemblage comprising over 200 species, and has no clear dominant taxa. Multivariate ordination of Alert data (by Canonical Correspondence Analysis) shows that diatom communities are most closely related to pH, conductivity and a nitrogen gradient. These autecological data will be used to interpret paleolimnological changes in sediment cores collected from these sites.
Bibliography of Canadian Geomorphology