CGRG Bibliography of Canadian Geomorphology
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Author : Bunbury, J.; and Gajewski, K.
Date : 2009.
Title : Evidence of the Younger Dryas cold episode in lake sediments from the southwest Yukon.
Publication : 2009 Annual Meeting of the Canadian Association of Geographers. May 26-30, 2009. Carleton University, Ottawa, Ontario.
Issue :
Page(s) :
Abstract
White spruce trees from 28 sites in Old Crow Flats were sampled to explore the climatic sensitivity of tree growth and its potential to characterize climatic variability over the last several centuries. A subset of samples has been processed and aggregated into a regional ring-width index (1632-2006) to remove site-specific trends. During the early part of the record (1632-1780), the low-frequency growth trend was stable with little to no slope and was followed by a decline until roughly 1860. Subsequently, growth rates rebounded to higher levels until the mid-1900’s followed by a brief decline and then a pronounced rise to present levels which exceed those of any other period on record, a pattern that is highly reminiscent of northern hemisphere temperature trends. It is unknown why growth rates are so high today compared to the past, but it is assumed that modern climatic conditions are more favourable for growth. Correlation analysis between regional growth and local climate data indicates that growth is influenced by winter precipitation, perhaps reflecting a biological dependence on groundwater recharge from snowmelt. Summer temperatures also have a positive effect on growth which is consistent with climate-growth relations commonly observed at northern treeline.
Bibliography of Canadian Geomorphology