Holocene Climate Based on Pollen Transfer Functions, Eastern Canadian Arctic

Abstract

Transfer functions are developed for a north-south transect in the eastern Canadian Arctic (from Clyde River to Fort Chimo) based on surface pollen samples. The Imbrie/Kipp and multiple stepwise linear regression models are used to show the statistical association between percentages of 19 pollen taxa and climatic variables (January, June, July, and summer temperatures, Young's index of summer warmth, and summer [JJA] precipitation). Multiple correlation coefficients are high and standard deviations of temperature estimates are less than ± 1°C and 2.5 cm. The problem of the local variability of pollen in surface mosses is considered through an analysis of the results of the transfer functions on 69 additional modern surface samples from around Fort Chimo, Frobisher Bay, Pangnirtung, Broughton Island, and Clyde River. Good agreement exists between the predicted July temperatures based on the transfer functions and adjacent weather station records. The transfer functions are applied to four fossil peat pollen sequences on Cumberland Peninsula. These spectra provide a nearly continuous record that covers the last 6000 yr. Analysis of the fossil materials provides estimates of July T°C and summer precipitation (cm). A period of warmer and wetter conditions generally prevailed between 6000 and 4000 BP although this climate was punctuated by cooler conditions circa 4800 yr ago. Over the last 3600 yr the pollen record from Windy Lake shows a progressive decline in July temperature. Superimposed on this trend are a number of temperature oscillations which show correspondence with other regional proxy climatic records.