Holocene climate and vegetation change on Victoria Island, western Canadian Arctic

A detailed pollen record from Victoria Island provides the first quantitative Holocene climate reconstruction from the western Canadian Arctic. The pollen percentage data indicate that Arctic herbs increased over the Holocene in response to long-term cooling. The influx of locally and regionally derived pollen grains varies throughout the core and tracks several major changes observed in the biogenic silica record from Arolik Lake, Alaska, and the GISP2 ice-core, suggesting that climate change closely controlled Arctic plant productivity. Using modern analogue and transfer function techniques, we generated quantitative reconstructions of mean July temperature and total annual precipitation for the past 10 000 years, to place recent climate changes within the context of Holocene climate variability. The quantitative reconstructions indicate that July temperature cooled by 1-1.5 degrees C during the Holocene. The pollen-based reconstructions record an increase in temperature of similar to 0.5 degrees C over the last 100 years, and the pollen percentage and influx data indicate impacts of recent warming on the regional vegetation. (C) 2007 Elsevier Ltd. All rights reserved.