Holocene climate change and landscape development from a low-Arctic tundra lake in the western Hudson Bay region of Manitoba, Canada

• Published in: Journal of paleolimnology 2012-06, Vol.48 (1), p.175-192
• Main Authors: Camill, Philip, Umbanhowar, Charles E., Jr, Geiss, Christoph, Hobbs, William O, Edlund, Mark B, Shinneman, Avery Cook, Dorale, Jeffrey A, Lynch, Jason
• Format: Article
• Language: English
• Subjects: Aquatic ecosystems; Arctic zone; Bacillariophyceae; bulk density; calcium; Charcoal; Climate Change; data collection; Earth and Environmental Science; Earth Sciences; Ecosystem dynamics; ecosystems; fossils; Freshwater; Freshwater & Marine Ecology; Geochemistry; Geology; Holocene; Lake sediments; Lakes; landscapes; magnesium; Magnetic properties; organic matter; Original Paper; Paleoclimate science; Paleolimnology; Paleontology; Peat; Physical Geography; Pollen; potassium; Sedimentology; Sediments; Silica; Stable isotopes; temperature; Tundra
• ISSN: 0921-2728; 1573-0417
• DOI: 10.1007/s10933-012-9619-0

The low-Arctic region of western Hudson Bay in interior Canada is one of the most poorly described areas of North America in terms of Holocene climate history. Here, we present new data from a well-dated lake sediment core from northern Manitoba, Canada. We assemble one of the richest multi-proxy datasets to date for a low-Arctic lake and characterize terrestrial and lake processes and exchanges between them. These proxies include fossil pollen and diatom assemblages, charcoal, magnetic properties (susceptibility and remanance), mineral grain size, bulk density, organic-matter content, elemental geochemistry, sediment cation (K+, Mg2+, Ca2+, Fe2+/Fe3+) and macronutrient (P, N, C) contents, biogenic-silica content, basal peat dates (wetland initiation), and stable isotopes (δ13C, δ15N). The sediment proxies record both broad- and fine-scale (millennial and sub-millennial) climate change. We find indirect evidence for a cool and dry post-glacial period from 9,000 to 6,500 cal yr BP, a warm and moist mid-Holocene period from 6,500 to 2,500 cal yr BP, and a cool and moist late-Holocene period from 2,500 cal yr BP to present. High-resolution geochemical data suggests 300- to 500-year-long dry periods at ~6,500–6,100, 5,300–5,000, 3,300–2,800, and 400–0 cal yr BP. These results suggest that terrestrial and aquatic ecosystem dynamics in the western Hudson Bay region are sensitive to past climate change and are likely to respond to future changes in temperature and precipitation.