High-Resolution Late Holocene Climate Change and Human Impacts on a Hypermaritime Peatland on Haida Gwaii, BC, Canada
A peat core from Sphagnum-dominated Drizzle Bog on Graham Island was used to identify factors that have influenced peatland development during the past ∼1800 years. High-resolution paleoecological analysis included percentage and accumulation rate diagrams of pollen and other microfossils. 210Pb dat...
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| Format: | Dissertation |
| Language: | English |
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ProQuest Dissertations & Theses
01-01-2012
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| Online Access: | Get full text |
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| Summary: | A peat core from Sphagnum-dominated Drizzle Bog on Graham Island was used to identify factors that have influenced peatland development during the past ∼1800 years. High-resolution paleoecological analysis included percentage and accumulation rate diagrams of pollen and other microfossils. 210Pb dates back to AD 1892 and four AMS radiocarbon dates provide a chronology of peat and microfossil accumulation back to AD 195. Few changes are evident before AD 1400 but a period of warm dry conditions is suggested by high pollen concentrations that coincide with high fire activity throughout the Yukon and Alaska. Low pollen accumulation between ∼ 1600 and 1875 support cool growing seasons during the Little Ice Age (LIA). Dramatic increases in regional pollen productivity support rapid warming following the LIA after 1875. Construction of a gravel road through the bog in 1958 likely altered local hydrology as evidenced by changes in communities of rhizopoda and other organisms. Keywords: Sphagnum; Little Ice Age; Haida Gwaii; Peat accumulation; Pollen accumulation rate; Industrial Period warming. |
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| ISBN: | 9780499227553 0499227557 |