A preliminary application of the analogue approach to the interpretation of late quaternary pollen spectra from southeastern Australia (original) (raw)
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Review of Palaeobotany and Palynology, 1994
Most information and ideas on regional patterns of climate change and vegetation response within the late Quaternary have been derived from pollen studies in previously glaciated areas of the northern hemisphere, which may not be representative of the terrestrial environments of the world as a whole. This paper presents initial results from a project designed to help redress this global imbalance. Specifically, modem and pre-European pollen samples from 71 pollen diagrams from sea level to ca. 2000m, covering a mean annual precipitation range of 1600 mm and a temperature range of 13°C in southeastern Australia are examined to assess their application to quantitative reconstruction of past regional patterns of vegetation and climate from the fossil pollen data. It is concluded that the pre-European rather than modem pollen samples provide potentially more suitable analogues for past vegetation. A range of climatic indicator taxa are identified, but variability within the pollen data will place some constraints on the degree of resolution achievable in vegetation and climatic reconstructions.
Australian Journal of Botany, 1997
Seventy-one pollen spectra from prior to the period of European impact were extracted from fossil pollen diagrams on mainland south-eastern Australia in 1991 to use as a modern reference for refinement of vegetation and climatic histories constructed from the region. This paper presents results of an extension of this recent database to 135 spectra, derived from additional fossil pollen sites on the mainland and also from sites in Tasmania. The sites include those of almost all late Quaternary pollen studies ever undertaken. Estimates of climate for each site, derived by BIOCLIM, have allowed an examination of patterns of representation of individual recorded taxa in relation to regional variation in major climatic parameters. Pollen taxa show variable representation in relation to their inferred presence and abundance in parent vegetation due to differential pollen production and dispersal characteristics. However, patterns of pollen representation do appear to relate, in broad terms, to climatic variation. It is considered that this modern pollen and climate database should lead to more certain interpretation of future pollen records including some quantification of palaeoclimatic conditions. Percentages of those taxa excluded from the pollen sum for pre-European spectra of south-eastern Australian pollen diagrams, ordered along the gradient of mean annual precipitation.
Quaternary Science Reviews, 2007
A review of Holocene climate patterns in eastern Australia is presented on the basis of a series of high-resolution pollen records across a north-to-south transect. Previously published radiocarbon data are calibrated into calendar years and fitted with an age-depth model. The resulting chronologies are used to compare past environmental changes and describe patterns of climate change on a calendar-age scale. Based on the present-day Australian climate patterns and impact of the El Nin˜o-Southern Oscillation (ENSO), the palynological data are interpreted and the prevalent climate mode throughout the Holocene reconstructed. Results show that early Holocene changes are strongly divergent and asynchronous between sites, while middle to late Holocene conditions are characterized by more arid and variable conditions and greater coupling between northern and southern sites, which is in agreement with increasing influence of ENSO. r
Journal of the Royal Society of Western Australia, 2006
Pollen was collected from the surface sediments of 16 wetland basins situated on a beachridge plain in the Becher Point area, southwestern Australia. Sampling was undertaken to determine the ratio of wetland/upland plant species contributing to the surface pollen in each wetland, to determine the contributions of local and regional pollen, and to develop indicator pollen assemblages as a baseline to interpret fossil Holocene sequences. The main wetland plant assemblages colonising the wetlands include sedges - Baumea articulata (R. Br.) S. T. Blake;. TyphaL. spp.; mixed Baumea articulata and Typha spp.; Isolepis nodosa (Rottb.) R. Br.; Baumea juncea(R. Br.) Palla; Lepidosperma gladiatum Labill.; rushes - Juncus krausii Hochst.; grasses - Sporobolus virginicus (L.) Kunth.; shrubs - Melaleuca viminea Lindley; Melaleuca teretifolia Endl.; grass trees - Xanthorrhoea preissii Endl.; trees and shrubs - Melaleuca rhaphiophylla Schauer,Melaleuca cuticularis Labill. The pollen assemblages re...
Evaluation of a modern-analogue methodology for reconstructing Australian palaeoclimate from pollen
2016
Quantitative palaeoclimate reconstructions are widely used to evaluate climate model performance. Here, as part of an effort to provide such a data set for Australia, we examine the impact of analytical decisions and sampling assumptions on modern-analogue reconstructions using a continent-wide pollen data set. There is a high degree of correlation between temperature variables in the modern climate of Australia, but there is sufficient orthogonality in the variations of precipitation, summer and winter temperature and plant–available moisture to allow independent reconstructions of these four variables to be made. The method of analogue selection does not affect the reconstructions, although bootstrap resampling provides a more reliable technique for obtaining robust measures of uncertainty. The number of analogues used affects the quality of the reconstructions: the most robust reconstructions are obtained using 5 analogues. The quality of reconstructions based on post-1850 CE pol...
Review of Palaeobotany and Palynology, 1994
Pollen samples from moss polsters and litter were taken from 14 florlstlcally-descnbed ralnforest and marginal ralnforest sites considered to cover a large range of existing environmental variation. One hundred and forty pollen types were Identified of whach only a small number could be related to parent species. However, a number of pollen types had systematic representation in relation to major environmental parameters, and pattern analyses revealed marked similarines in spatial distributions of sites based on pollen and species data. Site ordination demonstrated high correlation between pollen variation and annual and seasonal attributes of chmate as well as soil fertility indicating the potentxal for refining palaeoenvironmental reconstructions from pollen diagrams produced from the region.
Palaeogeography Palaeoclimatology Palaeoecology, 1995
Analyses of pollen and charcoal from lake and swamp deposits accumulated in a maar crater are used to reconstruct palaeoenvironments at and around Terang, Western Victoria. Changes in the nature of the sediments and in aquatic and dryland pollen indicate substantial climatic variation within the recorded period. Pollen assemblages indicate changes from open woodland, herbfield and grassland to wet sclerophyll forest, and from ephemeral swamp to permanent lake and swamp conditions within the basin.A possible timescale for the Lake Terang sequence is inferred from comparison with the better dated, nearby Lake Wangoom sequence and with the deep sea core record. The Terang record is considered to span a large part of the last glacial period and the Holocene, extending the available record of past vegetation and environments from the region by some 25,000 years to around 75,000 yr B.P.Conditions during the earlier part of the last glacial period were cooler and drier than today with open Casuarina woodland predominating in the region. At times, particularly towards the end of this period, conditions are considered to have been more extreme as much of the pollen is oxidised. A major interstadial, whose termination is tentatively dated at about 48,000 yr B.P. was dominated by Eucalyptus forest under effective precipitation levels similar to those of today. The latter part of the last glacial period is considered to have been cold and dry although no pollen is preserved except during a short phase of amelioration, probably around 39,000 yr B.P. The Holocene has been characterised by mixed Casuarina and Eucalyptus woodland and forest until recent changes brought about by European people. Fire has been a constant feature of the environment and its influence on changing vegetation patterns cannot be determined with certainty.
A 23,000-yr pollen record from Lake Euramoo, wet tropics of NE Queensland, Australia
Quaternary Research, 2005
A new extended pollen and charcoal record is presented from Lake Euramoo, Wet Tropics World Heritage rainforest of northeast Queensland, Australia. The 8.4-m sediment core taken from the center of Lake Euramoo incorporates a complete record of vegetation change and fire history spanning the period from 23,000 cal yr B.P. to present. The pollen record is divided into five significant zones; 23,000 -16,800 cal yr B.P., dry sclerophyll woodland; 16,800 -8600 cal yr B.P., wet sclerophyll woodland with marginal rainforest in protected pockets; 8600 -5000 cal yr B.P., warm temperate rainforest; 5000 -70 cal yr B.P., dry subtropical rainforest; 70 cal yr B.P. -A.D 1999, degraded dry subtropical rainforest with increasing influence of invasive species and fire.
Review of Palaeobotany and Palynology, 2002
Pollen and charcoal analysis on marine sediment core Fr10/95, GC-17 provides a record of vegetation, fire and climate change for the last 100 ka, with a hiatus from 64 to 46 ka, for the Cape Range Peninsula, Western Australia. Our results indicate significantly drier conditions and reduced summer rain after 46 ka compared with 100^64 ka. Periods of maximum summer rain occurred at 100, 80 and 70 ka. Vegetation changed from open Eucalyptus woodlands rich in grasses to open Eucalyptus and Gyrostemon shrublands rich in Chenopodiaceae/Amaranthaceae and Asteraceae Tubuliflorae, in the period from 46 to 40 ka. The charcoal record does not suggest human involvement in this vegetation change. The period from 14 to 3 ka was wetter with heavier summer rain compared to today, probably as a result of higher sea-surface temperatures. Increased strength of the Leeuwin Current during the last 5000 years is suggested by the presence of Pteridophyta spores derived from Indonesia. ß 0034-6667 / 02 / $^see front matter ß 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 3 4 -6 6 6 7 ( 0 2 ) 0 0 0 7 5 -1