The Winnipeg River Drainage Basin (WRDB), located in the boreal forest region of Canada, is a pivotal region of focus for the assessment of water availability to determine susceptibility to drought in the past. To date, there have been relatively few paleolimnological studies focusing on how lake levels have changed in the past and whether these changes have been synchronous in the WRDB. This study investigates temporal patterns in effective moisture from Little Raleigh Lake over the last two millennia. Analyses are based on diatoms from two near-shore sediment cores from different locations and water depth in Little Raleigh Lake. Changes in diatom assemblages are used to reconstruct quantitative estimates of effective moisture in the past through the calibration of a diatom-inferred depth model developed from diatom assemblages in surficial sediments along a depth transect in Little Raleigh Lake. Declines of ~1-3m occurred during the late Holocene, with prolonged periods of aridity consistent with the timing of the Medieval Climate Anamoly (~950-1250AD) and the Little Ice Age (~1650-1750AD). The nearshore core retrieved closer to the present-day ecotone between the benthic and planktonic diatom assemblages was more sensitive to tracking water level changes in the lake than the deeper core. Conditions during the last two millennia can be used for the assessment of water availability in the past, and may offer insight on future conditions under increasing temperatures. / Thesis (Master, Biology) -- Queen's University, 2011-07-29 17:09:49.155
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/6627 |
| Date | 10 August 2011 |
| Creators | Ma, Susan |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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