Holocene climate change and landscape development from a low-Arctic tundra lake in the western Hudson Bay region of Manitoba, Canada
Holocene climate change and landscape development from a low-Arctic tundra lake in the western Hudson Bay region of Manitoba, Canada
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加拿大马尼托巴省哈德逊湾西部地区低北极苔原湖的全新世气候变化和景观发展
DOI：
10.1007/s10933-012-9619-0
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发表时间：
2012
影响因子：
2.1
通讯作者：
Lynch, Jason
中科院分区：
文献类型：
--
作者：
Camill, Philip;Umbanhowar, Charles E.;Geiss, Christoph;Hobbs, William O.;Edlund, Mark B.;Shinneman, Avery Cook;Dorale, Jeffrey A.;Lynch, Jason
加拿大内陆哈德逊湾西部的低北极地区是北美全新世气候历史中描述最少的地区之一。在这里，我们提出了新的数据，从北方马尼托巴，加拿大的一个很好的湖泊沉积物的核心。我们组装一个最丰富的多代理数据集，以低北极湖和表征陆地和湖泊的过程和它们之间的交流。这些代用指标包括化石花粉和硅藻组合、木炭、磁性（磁化率和剩磁）、矿物粒度、体积密度、有机质含量、元素地球化学、沉积物阳离子（K+、Mg 2+、Ca 2+、Fe 2 +/Fe 3+）和常量营养素（P、N、C）含量、生源硅含量、基底泥炭日期（湿地形成）和稳定同位素（δ 13 C、δ 15 N）。沉积物代用指标记录了大尺度和小尺度（千年和亚千年）的气候变化。我们发现了间接的证据，从9,000至6,500卡年BP，温暖和潮湿的中全新世时期从6,500至2,500卡年BP，和凉爽和潮湿的晚全新世时期从2,500卡年BP到现在的凉爽和干燥的冰后期。高分辨率地球化学数据表明，在距今约6，500 - 6，100、5，300 - 5，000、3，300 - 2，800和400-0 cal/yr BP的干旱期长达300- 500年。这些结果表明，在西部哈德逊湾地区的陆地和水生生态系统动态是敏感的过去的气候变化，并有可能响应未来的温度和降水的变化。
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.