Limnology and diatom paleoecology of lakes and ponds on Banks Island, N.W.T. and Devon Island, Nunavut, Canadian Arctic.
Published: 2004
Language: eng
Number of pages: 350
Description: The Canadian Arctic Archipelago is an important reference region for climate change studies, however a paucity of environmental data exists for this area. With the aim to document and characterize the effects of climate change in this high-latitude region, this thesis establishes baseline environmental conditions and investigates long-term climate trends on Banks Island, NWT. and Devon Island, Nunavut through the use of limnological and paleolimnological techniques. Both islands were previously unsurveyed limnologically, and in the case of Banks Island, no previous paleolimnological study had been conducted on this island.A diatom-based TN transfer function for Banks Island was developed for application to three recovered sediment cores. A general increase in species diversity was documented in all stratigraphies, although to a lesser degree in the lake than in the ponds. Meteorological data for Banks Island from the last 50 years also showed an increase in both total annual precipitation and annual mean July temperatures.Mean total nitrogen (TN) and total phosphorus (TP) concentrations on Banks Island were demonstrably higher than those reported by previous Arctic island limnological surveys. Furthermore, Banks Island provided an opportunity to observe limnological trends across three ecozones (Low, Mid and High Arctic), as each study site could each be classified into one of these three ecozonal designations based on their nutrient and dissolved organic carbon concentrations. The limnological characterization of Devon Island revealed that its inland water bodies are generally homogeneous, being ultra-oligotrophic and dilute. The exceptions were those water bodies associated with the impact-generated carbonate melt sheets found within the boundaries of Haughton Crater in the northwestern region of Devon Island.The diatom autecology of the inland lakes and ponds on Devon Island was also characterized, resulting in the development of a diatom-based soluble reactive phosphorus transfer function, and its application to a lake sediment core. This study demonstrated both the homogeneity of the inland water bodies on this island, and their differences from the coastal lakes and ponds. Interestingly, the diatom stratigraphy did not reflect the species assemblage shifts seen in other Arctic Island paleolimnological and ice core reconstructions.
Notes: Adviser:  Marianne Douglas.

Thesis (Ph.D.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2312.