A Vegetation History of the Far North of New Zealand during the Late Otira (Last) Glaciation

1993 ◽  
Vol 39 (3) ◽  
pp. 361-372 ◽  
Author(s):  
Rewi Newnham ◽  
John Ogden ◽  
Dallas Mildenhall
Keyword(s):  
New Zealand ◽  
Forest Cover ◽  
Vegetation History ◽  
Mixed Forest ◽  
Radiocarbon Dates ◽  
Substantial Loss ◽  
Far North ◽  
Last Glaciation ◽  
Pollen Diagrams ◽  
History Of

AbstractDuring the latter part of the last (Otira) glaciation the forest cover of New Zealand was much reduced. It has frequently been postulated, however, that diverse mixed forest communities survived in the far north of North Island. Pollen diagrams and radiocarbon dates from two last glacial and postglacial (Aranuian) sits on the Aupouri Peninsula in the far north of New Zealand are compared with other published palynological and plant macrofossil evidence from the region. Mixed kauri/podocarp/angiosperm forest was present at times during the late Otiran (and Aranuian) and no evidence was found for substantial loss of forest. However, radiocarbon samples from one site, at least, seem to have been contaminated with young carbon; this introduces uncertainty into the chronology established at that site. Possibly nondeposition or erosion has obscured part or all of the late Otiran record at all the sites studied so that very much reduced forest cover at that time cannot be ruled out.

Holocene vegetation history of Banks Island, Northwest Territories, Canada

2000 ◽  
Vol 78 (4) ◽  
pp. 430-436 ◽  
Author(s):  
K Gajewski ◽  
R J Mott ◽  
J C Ritchie ◽  
K Hadden
Keyword(s):  
Northwest Territories ◽  
Vegetation History ◽  
Middle Zone ◽  
Pollen Diagram ◽  
Radiocarbon Dates ◽  
Banks Island ◽  
Pollen Diagrams ◽  
Pollen Types ◽  
History Of ◽  
Lower Frequencies

Four pollen diagrams from Banks Island, Northwest Territories, provide the first records of the postglacial vegetation of the region. Chronologies are estimated from radiocarbon dates and by correlation of the exotic-pollen curves to data from the mainland. The pollen stratigraphies from all sites can be divided into three zones, where the middle zone, dating from 7000 to 2000 BP, corresponds to the warmest time. Although both the first and third zones correspond to cooler periods, the vegetation of the earliest zone was not identical to that of the latest, indicated by lower frequencies of key pollen types such as those of Dryas and Saxifraga.Key words: Banks Island, Holocene, pollen diagram, Arctic, paleoecology, Quaternary.

The last glaciation and sea level history of Fosheim Peninsula, Ellesmere Island, Canadian High Arctic

1996 ◽  
Vol 33 (7) ◽  
pp. 1075-1086 ◽  
Author(s):  
Trevor Bell
Keyword(s):  
High Arctic ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
Ice Caps ◽  
Marine Deposits ◽  
Last Glaciation ◽  
Maximum Elevation ◽  
Glacier Runoff ◽  
History Of ◽  
Ice Conditions

The last glaciation of Fosheim Peninsula is reconstructed on the basis of landform and sediment mapping and associated radiocarbon dates. Ice growth involved the expansion of cirque glaciers and accumulation on upland surfaces that are now ice free. Limited ice buildup, despite lowering of the paleoglaciation level by 700–800 m, is attributed to the hyperaridity of the region during glacial conditions. Marine deposits in formerly submerged basins beyond the ice margins are interpreted to represent (i) sedimentation caused by local ice buildup and marine transgression by 10.6 ka BP, (ii) increased ablation and glacier runoff [Formula: see text]9.5 ka BP, and (iii) marine regression during the Holocene. Holocene marine limit reaches a maximum elevation of approximately 150 m asl along northern Eureka Sound and Greely Fiord and descends southeastwards to 139–142 m asl near the Sawtooth Mountains. A synchronous marine limit is implied where the last ice limit was inland of the sea. The magnitude and pattern of Holocene emergence cannot be fully explained by the glacioisostatic effects of the small ice load during the last glaciation of the region. Deglaciation of the peninsula was underway by 9.5 ka BP; however, local ice caps may have persisted through the wannest period of the Holocene until 6–5 ka BP. This was likely a function of reduced sea ice conditions and increased moisture availability which benefited low-lying coastal icefields, but had negligible effect on interior highland ice caps.

Vegetation History and Water Fluctuations at Lake Leake, South-Eastern South Australia. II. 50 000 B.P. To 10 000 B.P

1975 ◽  
Vol 23 (5) ◽  
pp. 815 ◽  
Author(s):  
JR Dodson
Keyword(s):  
Vegetation History ◽  
South Australia ◽  
Annual Rainfall ◽  
Drill Core ◽  
Radiocarbon Dates ◽  
Last Glaciation ◽  
Annual Minimum Temperature ◽  
Average Annual Rainfall ◽  
Eucalypt Woodland ◽  
Open Woodland

A drill core from Lake Leake contains a sedimentary sequence extending from about 50,000 B.P. until the present. This paper discusses the results of the pollen analyses and six radiocarbon dates which span the period from about 50,000 until about 10,000 B.P. There are core sections which yielded low numbers of pollen and thus there are gaps in the vegetation record. It is suggested that open eucalypt woodland was replaced by eucalypt woodland with heath at about 50,000 B.P. and remained until about 39,000 B.P. Open woodland then returned but was replaced by eucalypt woodland with heath by 38,000 B.P. Some time after 35,000 B.P., open eucalypt woodland conditions returned and persisted until near 10,000 B.P. when Casuarina stricta migrated into the area. Through- out the period in question the climate was drier than it has been in the last 10,000 radiocarbon years. There were wet periods about 50,000 and 39,000 B.P. and from 38,000 to 35,000 B.P. The character of the sediments and the relative amounts of pollen preserved suggest that conditions were relatively dry from 50,000 to 39,000 B.P. and from after 35,000 until near 10,000 B.P. The lake was driest during the period of the last glaciation but the presence of eucalypt pollen is interpreted as indicating that the average annual minimum temperature was above 10�C and the average annual rainfall was above 20-25 cm.

The interpretation of some post-Glacial vegetation diversities at different Lake District sites

1965 ◽  
Vol 161 (984) ◽  
pp. 310-323 ◽  
Keyword(s):  
Lake Sediments ◽  
Drainage Basin ◽  
Large River ◽  
Single Type ◽  
Lake District ◽  
Drainage Basins ◽  
Radiocarbon Dates ◽  
Pollen Diagrams ◽  
History Of ◽  
The Individual

The lake sediments which have been described by Mr Mackereth contain pollen and other plant remains which record the broad outlines of vegetational history. Many pollen diagrams are now available from the one ecologically homogeneous area of the central Lake District; their similarities record the effects of a single type of climate on an area of uniformly ancient rock, while their diversities record the individual history of each drainage basin. The large river valley lakes such as Windermere represent an integration of the many small drainage basins of which the river systems are made up; a simpler ecological picture is presented by the small lakes or tarns. Mackereth’s hypothesis, based on purely chemical evidence, that the lake sediments are derived from a series of soils washed in from the drainage basins, is supported by all the pollen evidence. Two deductions are made from this accepted assumption—first, that radiocarbon assay of the lake muds would be of comparatively little value, since the organic matter in any sample may have originated from a soil and be much older than its date of incorporation in the lake mud, and secondly that the presence of derived pollen from soils must be considered in interpretation of the pollen diagrams. The outline of the ecological history of the Lake District attempted here must therefore be built up by synthesis and comparison, but, as yet, in the absence of radiocarbon dates. The advantages of lake sediments for post-Glacial investigation—to set against their limitations—are that there is no overwhelming local pollen component as in fen or bog peats, and that stratigraphical changes in the sediments provide evidence for major changes in erosion rate, which can be correlated with vegetation changes shown in the pollen diagrams—as can chemical changes related to soil changes in the drainage basins.

Holocene to Middle Last Glaciation vegetation history at Tullabardine Dam, western Tasmania

1986 ◽  
Vol 229 (1255) ◽  
pp. 177-207 ◽  
Keyword(s):  
New Zealand ◽  
Lake Sediments ◽  
Pollen Analysis ◽  
Temperate Forest ◽  
Vegetation History ◽  
Late Glacial ◽  
Pollen Assemblage ◽  
Temperate Rainforest ◽  
Last Glaciation ◽  
Peat Swamp

Pollen analysis of 4 m of peat, swamp-soil and lake sediments dated from 0 to > 43800 years b.p. indicates the occurrence of three major pollen assemblage zones. During Zone 1 (11000-0 years b.p.) the area had temperate rainforest and the climate was warm, moist and interglacial. During Zone 2 ( ?25000-l 1000 years b.p.), correlated approximately with the last period of glaciation, the vegetation was mainly grassland and the climate was considerably colder than present. In late glacial times (14000-11000 years b.p.) pollen of shrub and tree taxa increased, especially during the later part of the period as the climate became warmer and moister. During Zone 3 (more than 4 3 0 0 0 -?25000 years b.p.) the vegetation was predominantly sub-alpine and alpine. This vegetation represents an interstadial assemblage for a lowland site. The climate was cool and moist. The results are compared with sites of similar age in Tasmania, and with sites from temperate forest environments in Chile and New Zealand.

Growth and Vegetation History of Alpine Mires on the Old Man Range, Central Otago, New Zealand

1997 ◽  
Vol 29 (1) ◽  
pp. 32 ◽  
Author(s):  
M. S. McGlone ◽  
N. T. Moar ◽  
C. D. Meurk
Keyword(s):  
New Zealand ◽  
Vegetation History ◽  
History Of

Climatic Implications of Macro- and Microfossil Assemblages from Late Pleistocene Deposits in Northern New Zealand

1993 ◽  
Vol 39 (1) ◽  
pp. 107-119 ◽  
Author(s):  
John Ogden ◽  
Rewi M. Newnham ◽  
Jonathan G. Palmer ◽  
Richard G. Serra ◽  
Neil D. Mitchell
Keyword(s):  
New Zealand ◽  
Plant Species ◽  
Tree Species ◽  
Climatic Conditions ◽  
Species Level ◽  
Decomposition Rates ◽  
Radiocarbon Dates ◽  
Far North ◽  
Pollen Rain ◽  
Similar Temperature

AbstractTwenty-two plant species were identified from leaves, fruits, or flowers, and 41 taxa from pollen, present in a macrofossil (leaf) layer in a peat swamp formed on Pleistocene dunes on the Aupouri Peninsula in northern New Zealand. Eight genera of gymnosperms are represented. With the exception of Lagarostrobos colensoi, all tree species abundant as macrofossils are also common as pollen. Macrofossils enabled the on-site flora to be compared with the regional flora, represented by the pollen rain. Studies on leaf decomposition rates indicate bias toward sclerophyllous species in the macrofossils. Identification to species level and treering data from preserved kauri logs allow quantitative comparisons with similar extant communities. Current climatic conditions at those analogue sites are cooler (2° to 3°C), cloudier (11%), and much wetter (85%) than those currently prevailing on the Aupouri Peninsula. Dendrochronological results also suggest that the far north of New Zealand had a cooler, cloudier, and wetter climate at the time the fossil leaf assemblage was formed. Radiocarbon dates from possibly contaminated samples suggest that a diverse mixed gymnosperm/angiosperm forest, dominated by kauri (Agathis australis), was present about (or sometime before) 41,00034,000 yr B.P., when the leaf layer was formed. Similar temperature reductions have been postulated for this period in New Zealand by other authors.

scholarly journals Zur Pollenanalyse von Lössen: Untersuchungen der Lößprofile von Oberfellabrunn und Stillfried (Niederösterreich)

1964 ◽  
Vol 15 (1) ◽  
pp. 5-39
Author(s):  
Burkhard Frenzel
Keyword(s):  
Plant Communities ◽  
Vegetation History ◽  
Northern Eurasia ◽  
Loamy Soil ◽  
Plant Associations ◽  
Surface Samples ◽  
Last Glaciation ◽  
Steppe Communities ◽  
History Of ◽  
Eemian Interglacial

Abstract. A method for pollenanalytical investigations of loesses is described. If several sources of error are duely taken into consideration, this method is successful in the reconstruction of the vegetation history of those phases of pleniglacial times, during which the thick loess layers were accumulated. The method can be employed in pollenanalytical investigations of weathered and unweathered loesses, with the exception of redeposited loesses. It can be shown that the famous sequence of fossil soils at Oberfellabrunn, known as the soils of the "Fellabrunner Komplex" („Stillfried A"), which is sometimes held to be the equivalent of the "Göttweig Interstadial", must be divided into the brown loamy soil at the base of the sequence, which was formed during the Eemian Interglacial, and into the younger humic layers, which developed during the Interstadials of Amersfoort and Brørup. The amelioration of climate during the "Stillfried B-Interstadial" (perhaps equivalent of the "Paudorf Interstadial"?) was strong enough to enable local subalpine conifer forests and riverine broad-leaved forests to spread along the rivers and other suitable places within the still dominant steppe formations on the drier loess plateaus. The loess layers of the Riss and Würm glaciations have been accumulated within the eastern Dart of Niederösterreich in different steppe communities, which can be described at best as belonging to the Gramineae steppe formation, rich in herbaceous plants. Sometimes there occurred plants of recent tundra-communities in the loess steppe: but real tundras did not exist at that time in Niederösterreich. This holds true most of all for the last period of loess accumulation after the Stillfried B-Interstadial. When being compared with pollen spectra of surface samples of recent tundra, steppe and semidesert plant communities, it becomes evident, that the open vegetation, thriving during the last glaciation in vast regions of Northern Eurasia cannot be described in terms of modern plant associations.

scholarly journals Continuous vegetation record of the Greater Cape Floristic Region (South Africa) covering the past 300 thousand years (IODP U1479)

2021 ◽  
Author(s):  
Lydie M. Dupont ◽  
Xueqin Zhao ◽  
Chistopher Charles ◽  
J. Tyler Faith ◽  
David Braun
Keyword(s):  
South Africa ◽  
Vegetation History ◽  
Modern Human ◽  
Cape Floristic Region ◽  
Archaeological Record ◽  
The Past ◽  
Modern Human Origins ◽  
Last Glaciation ◽  
History Of ◽  
The Last Glacial

Abstract. The flora of the Greater Cape Floristic Region (GCFR) of South Africa is a biodiversity hotspot of global significance, and its archaeological record has contributed substantially to the understanding of modern human origins. For both reasons, the climate and vegetation history of south-western South Africa is of interest to numerous fields. Currently known paleo-environmental records cover the Holocene, the last glacial-interglacial transition and parts of the last glaciation but do not encompass a full glacial-interglacial cycle. To obtain a continuous vegetation record of the last Pleistocene glacial-interglacial cycles, we studied pollen, spores and micro-charcoal of deep-sea sediments from IODP Site U1479 retrieved from SW of Cape Town. We compare our palynological results of the Pleistocene with previously published results of Pliocene material from the same site. We find that the vegetation of the GCFR, in particular Fynbos and Afrotemperate forest, respond to precessional forcing of climate. The micro-charcoal record confirms the importance of fires in the Fynbos vegetation. Ericaceae-rich and Asteraceae-rich types of Fynbos could extend on the western part of the Palaeo-Agulhas Plain (PAP), which emerged during periods of low sea-level of the Pleistocene.

Holocene Vegetation History of the Prince William Sound Region, South-Central Alaska

1983 ◽  
Vol 19 (3) ◽  
pp. 337-355 ◽  
Author(s):  
Calvin J. Heusser
Keyword(s):  
Vegetation History ◽  
Influential Factor ◽  
Tectonic Activity ◽  
Prince William Sound ◽  
Sedimentary Records ◽  
South Central ◽  
Peat Deposits ◽  
Pollen Diagrams ◽  
History Of ◽  
Fossil Records

AbstractVegetation history during the Holocene is interpreted from the pollen and sedimentary records of nine sections of peat deposits located in sedge tundra at sites in the northern and northwestern parts of the Prince William Sound region. Basal radiocarbon ages of the deposits are between 10,015 and 580 yr B.P. Modern surface pollen data from these and 25 additional sites, ranging from lowlands to an altitude of 675 m in the alpine tundra, were used to aid in the interpretation of the fossil records. Both frequency and influx pollen diagrams of the oldest section disclose a sequence of communities beginning with sedge tundra, containing thickets of willow and alder, followed by alder, which became predominant at about 8300 yr B.P. Later, alder declined, and an inferred growth of sedge tundra and the establishment of colonies of mountain hemlock and Sitka spruce with some western hemlock occurred about 2680 yr B.P. Finally, regrowth of sedge tundra accompanied by the development of forest communites took place over the past 2000 yr. The influence of glacier advances on the vegetation in the fjords occurred during Neoglacial episodes dated at 3200–2500 yr B.P. and during recent centuries. Regional Holocene tectonic activity was also an influential factor, especially at the time of the 1964 earthquake.

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