Modern Pollen Deposition and Holocene Paleotemperature Reconstructions, Central Northern Canada

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. INSTAAR, University of Colorado andThe Regents of the University of Colorado, a body corporate, contracting on behalf of the University of Colorado at Boulder for the benefit of INSTAAR are collaborating with JSTOR to digitize, preserve and extend access to Arctic and Alpine Research.ABSTRACT The relative modern pollen spectra is reported for a transect from the edge of the boreal forest of Keewatin (ca. 600N), northeastward to the high arctic/polar desert environments of Clyde River, Baffin Island (ca. 710N). Two hundred and ninety-three surface moss polsters are analyzed from 29 sites. Thirteen modern pollen taxa (Alnus, Ericaceae, and Sphagnum) are used, in association with estimates of present temperature and precipitation, to construct transfer function equations from fossil pollen diagrams. Equations are derived using the Imbrie/Kipp (1971) approach and multiplex regression procedures. The resulting equations are all statistically significant with multiple correlation coefficients for summer temperatures of better than 0.9 with standard errors of + 1.00C or less. The transfer functions are used on four published pollen diagrams (Nichols, 1975) to predict July temperatures. The resulting time-series are presented as standardized departures from the mean July TOC at each of the four sites. A generalized reconstruction of the July temperature history of central northern Canada is then made by taking average departures for each of the four sites over the last 6000 yr. This shows (1) temperatures above average between 5500 and 4000 BP; (2) temperatures below average (or average) between 4000 and 3000 BP; (3) temperatures above average between 3000 and 2000 BP; and (4) temperatures below average between 2000 and the last few hundred years. In addition, on the basis of multivariate statistical analysis, we define four geographic pollen assemblage regions. Proceeding from south to north the pollen assemblages are Region I: Betula/Pinus/Picea/Ericaceae; Region II: Betula/Pinus/Ericaceae/Alnus; Region III: Ericaceae/Salix/Cyperaceae/Pinus; and Region IV: G rami ne ae/C ype raceae/Ericaceae/Salix. transect from the edge of the boreal forest of Keewatin (ca. 600N) to the high arctic-polar desert tundra of eastern Baffin Island (Figure 1). The modern pollen (i.e., pollen and spores) deposition which constitutes the basis for our paper was collected by Nichols in 1972 and 1973 as part of the Aerobiology Program for the U.S. International Biological Program.The concern with the future impact of rising CO2 levels in the atmosphere has prompted a considerable amount of research. 10 9 Bay EL 8 ' 6 !BAY ..f_ FIGURE 1. Location map of the 29 sites where surface moss polsters were collected. Th...

Quantitative analyses of modern pollen-climate relationships in New Zealand indigenous forests

“…Other studies (e.g., Andrews & Nichols 1981) have used this procedure. This reduced the data set from 161 sites to 94 sites.…”

Isopoll Maps and an Analysis of the Distribution of the Modern Pollen Rain, Eastern and Central Northern Canada

“…1B) were collected by: (1) Nichols in 1972-73 along a transect from southwestern Keewatin to Baffin Island (ANDREWS and NICHOLS, 1981); (2) Andrews, Mode, and assistants in the 1970's in Baffin Island (MODE, 1980), and (3) Elliott, Short, Stravers and Nichols in 1973, 1975-79 in Labrador-Ungava (ELLIOTT, 1979STRAVERS, 1981). Using these data, the surface pollen data for northwest Ungava reported by BARTLEY (1967), and the climatic data for selected variables (Table I).…”

“…Using these data, the surface pollen data for northwest Ungava reported by BARTLEY (1967), and the climatic data for selected variables (Table I). transfer function equations have been developed (ANDREWS and NICHOLS, 1981 ;Short, unpublished) for estimating the degree of climatic change for the region. NICHOLS (1975), SHORT (1978) andMODE (1980) described the preparation of pollen slides from surface moss and lichen polsters.…”

“…Counts inside the sum (with exclusions of spores and pollen from local peat producers) varied between 100 and 300 grains, but statistical analysis indicates that counts of 100 adequately represent the "true" proportion of pollen at a particular site (DAVIS, 1980;ANDREWS, et a/., 1980a). Because pollen from polsters may have a considerable "local" vegetational signal (BARTLEY, 1967;ADAM and MEHRINGER, 1975;WEBB, ef a/., 1978;ELLIOTT, 1979;ANDREWS and NICHOLS, 1981), we chose to extract the regional signal by computing means of the pollen percentages from several samples at each site (Table II). Eight taxa: Alnus Hill., Betula L., Picea Dietr., Pinus L, Salix L 1 Gramineae (Poaceae), Cyperaceae and Ericaeae 1 comprised 90 to 100% of the pollen counts in most samples.…”

Vegetation patterns, pollen deposition and distribution of non-pollen palynomorphs in an ice-wedge polygon near Kytalyk (NE Siberia), with some remarks on Arctic pollen morphology

“…Various studies have indeed dealt with modern pollen deposition in (sub)Arctic environments (e.g. Birks 1977Birks , 1980Andrews and Nichols 1981;Lamb 1984;Van der Knaap 1990;Eisner and Peterson 1998a;Lozhkin et al 2001;Whitmore et al 2005), but few deal with NE Siberia (e.g. Savelieva et al 2000;Bigelow et al 2003;Vasil'chuk 2005;Klemm et al 2013;Tarasov et al 2013) and only one addresses the typical short-distance vegetation patterns in a low-centred icewedge polygon mire ).…”