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Speleothems (cave calcite) provide many different proxy indicators for palaeoclimatic changes during the Quaternary era. Generally, the occurrence of growing speleothems is a strong proxy for global palaeoclimate, both geographically and through time. A database of speleothem U-Th ages shows some evidence for an early transition from the penultimate glacial to the last interglacial at -140 Ka BP. The database suggests an age of 63 Ka BP for the maximum cold period within isotope stage 4. Isotope stage 3 contains three periods of increased number of growing speleothems, at 40,50 and 56 Ka BP mainly in low latitude caves. The start of growth, growth rate, oxygen isotopes, carbon isotopes and luminescence intensity in two speleothems from southern Ireland provide high-resolution records of rapid palaeoclimate changes in that region during the Late Glacial. Several of these palaeoclimate proxies appear to be linked. The Younger Dryas (YO) cold event is dated at between 12.5 and 11.4 Ka BP in both speleothem records. The dominant agent of palaeoclimatic variation during the YD is probably changes in North Atlantic ocean circulation. A Microsoft Excel spreadsheet is developed as a means of rapidly converting between 14C and calendar years and vice versa.

No description available.

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The Lateglacial and Early Holocene are key periods with respect to the understanding of the present-day vegetation and environment. An interdisciplinary approach is important for the study of these changes. Only by interlinking biological and geoscience evidence can we obtain a more comprehensive picture of this key period. It is not possible to interpret any pollen spectrum in the sedimentary record without knowledge of the history of the locality and its vicinity. Rapid climate changes had a crucial effect on the environment and vegetation. Continentality of the climate and a deficit of precipitation amplify the effect of local conditions. Vegetation, as in the case of vertebrates and molluscs, comprises a combination of species of a continental steppe, mountain biotopes and disturbed habitats. This facilitated contact among species and populations that are biogeographically separated at present. Vegetation of the Lateglacial period in the Czech Republic ranges in character from frost barrens in the mountains, through steppe-tundra vegetation at medium altitudes to a continental steppe in the lowlands and pine woodlands constrained to a moist floodplain. The Western Carpathians were covered by a taiga. In the Pannonian Lowland, there were open forests with conifers and broadleaved woody plants....

Rich mollusc assemblages preserved in two profiles of fossiliferous sediment in the Blanský les area, provided the evidence about the Late Glacial and Holocene in this region, which is one of the most faunistically known areas of Central Europe. Findings of Quaternary faunas are very rare in Southern Bohemia, so these two soil profiles near Český Krumlov are so important for understanding the postglacial succession of Central Europe. The fossil mollusc assemblages showed an early appearance of forest species, which dominated both sites from the Boreal till Subboreal. Forest development in the Holocene Climatic Optimum reached a maximum, due to the absence of Neolithic man. Steppe species almost completely disappeared during this period. The development of the Young Holocene was linked to a decrease of the forest on the first site and the deforestation of the second site, due to a combination of a humidity decrease and human impact. In addition, some southern elements involved in the postglacial colonization of Central Europe, were found there. A few of them were found in a much older deposit than expected.

This dissertation project focuses on three study areas in the middle Tanana Valley (mTV) to provide records of local terrestrial ecological contexts and environmental changes in lowland settings that dated to the Late Glacial and early Holocene (16,000 to 6,000 cal. years ago) in interior Alaska and Eastern Beringia. The archaeological record of the mTV provides a rich history of hunter-gatherer land use dating over 14,000 years old. This project is part of two larger projects focused on prehistoric human ecology and foraging behavior in Eastern Beringia: the Quartz Lake-Shaw Creek Flats Multidisciplinary and Upward Sun River Site Projects. The study areas are spread out across a 4,000 km2 area in the mTV and contain the presence of archaeological sites that have records of well-developed stratification of sediments and soils and preserved macrofossils. Two of the study areas are dune fields: the Little Delta Dunes (including the Upward Sun River Site) and Rosa-Keystone Dunes Fields; the third area is Quartz Lake, one of the largest lakes within the region. As a whole they provide important information to understand the evolution of regional landscapes, paleoecological systems, and paleoenvironmental conditions dating back to 25,000 years ago, over 10,000 years prior to the currently accepted earliest human occupation of the region. Late Glacial and early Holocene landscapes of the mTV were ones of moderate stability and landscape disturbance with high rates of loess and aeolian sand deposition, and the presence of early-to-middle successional vegetation communities (herbs and forbs, shrubs, and deciduous trees) that fostered the presence of diverse mammalian faunal communities that no longer coexist in the region. As the middle Holocene approached, landscapes became increasingly stable with the expansion of the boreal forest and aeolian deposition drastically decreased throughout the mTV. The disturbances that fostered the highly productive early-to-middle successional vegetative communities in the Late Glacial and early Holocene became progressively partitioned in the middle Holocene and primarily relegated to active floodplains. These local ecological contexts can be used to assess changes in Late Glacial and Holocene faunal diversity and in human ecology and foraging behavior in interior Alaska and Eastern Beringia.

Most widely used applications of quantitative past vegetation reconstruction are based on pollen-vegetation relationship functions. To carry out detail vegetation reconstruction using this method, large amount of geographic data pre-processing is necessary. For this reason, large scale vegetation reconstructions are extremely rare. In this study data processing is carried out using automated GIS tools. Application of GIS enabled precise and detail reconstruction of the Late Glacial and Holocene forest vegetation composition, as well as the development of vegetation in Lithuania. New pollen investigations from cores and outcrops, created Lithuanian pollen database, evaluation of pollen-vegetation relationship functions in the environment of Lithuania and reconstruction of main tree species composition in the Late Glacial and Holocene, according to pollen database and selected pollen-vegetation relationship function are presented in this study. The created palaeovegetation maps enbled considerable detalization of knowledge about past vegetation in Lithuania. Consequently, main vegetation migration and distribution patterns were defined. / Plačiausiai naudojami kiekybinio praeities augalijos taksonominės sudėties atkūrimo pagal žiedadukių duomenis metodai remiasi žiedadulkių-augalijos priklausomybės funkcijomis. Norint atlikti detalų augalijos sudėties atkūrimą šiuo metodu, reikalingos itin didelės apimties geografinių duomenų apdorojimo procedūros, todėl stambiu masteliu augalijos sudėtis atkūriama itin retai. Šiame darbe duomenų apdorojimas atliekamas automatizuotomis GIS priemonėmis. GIS panaudojimas leido tiksliai ir detaliai atkurti Lietuvos vėlyvojo ledynmečio ir holoceno miško augalijos taksonominę sudėtį bei augalijos vystymosi raidą. Disertaciniame darbe pristatomi nauji gręžinių ir atodangų nuosėdų žiedadulkių tyrimai, sudaryta Lietuvos žiedadulkių duomenų bazė, atliktas įvairių žiedadulkių-augalijos priklausomybės funkcijų įvertinimas Lietuvos sąlygose, žiedadulkių duomenų bazės pagrindu pagal pasirinktą priklausomybės funkciją atkurta pagrindinių medžių taksonų sudėtis eilei vėlyvojo ledynmečio ir holoceno laikotarpių. Sudarytais praeities augalijos paplitimo žemėlapiais reikšmingai detalizuotos žinios apie praeities augaliją Lietuvoje, nustatyti pagrindiniai augalijos migracijos keliai ir jos paplitimo dėsningumai.

Plačiausiai naudojami kiekybinio praeities augalijos taksonominės sudėties atkūrimo pagal žiedadukių duomenis metodai remiasi žiedadulkių-augalijos priklausomybės funkcijomis. Norint atlikti detalų augalijos sudėties atkūrimą šiuo metodu, reikalingos itin didelės apimties geografinių duomenų apdorojimo procedūros, todėl stambiu masteliu augalijos sudėtis atkūriama itin retai. Šiame darbe duomenų apdorojimas atliekamas automatizuotomis GIS priemonėmis. GIS panaudojimas leido tiksliai ir detaliai atkurti Lietuvos vėlyvojo ledynmečio ir holoceno miško augalijos taksonominę sudėtį bei augalijos vystymosi raidą. Disertaciniame darbe pristatomi nauji gręžinių ir atodangų nuosėdų žiedadulkių tyrimai, sudaryta Lietuvos žiedadulkių duomenų bazė, atliktas įvairių žiedadulkių-augalijos priklausomybės funkcijų įvertinimas Lietuvos sąlygose, žiedadulkių duomenų bazės pagrindu pagal pasirinktą priklausomybės funkciją atkurta pagrindinių medžių taksonų sudėtis eilei vėlyvojo ledynmečio ir holoceno laikotarpių. Sudarytais praeities augalijos paplitimo žemėlapiais reikšmingai detalizuotos žinios apie praeities augaliją Lietuvoje, nustatyti pagrindiniai augalijos migracijos keliai ir jos paplitimo dėsningumai. / Most widely used applications of quantitative past vegetation reconstruction are based on pollen-vegetation relationship functions. To carry out detail vegetation reconstruction using this method, large amount of geographic data pre-processing is necessary. For this reason, large scale vegetation reconstructions are extremely rare. In this study data processing is carried out using automated GIS tools. Application of GIS enabled precise and detail reconstruction of the Late Glacial and Holocene forest vegetation composition, as well as the development of vegetation in Lithuania. New pollen investigations from cores and outcrops, created Lithuanian pollen database, evaluation of pollen-vegetation relationship functions in the environment of Lithuania and reconstruction of main tree species composition in the Late Glacial and Holocene, according to pollen database and selected pollen-vegetation relationship function are presented in this study. The created palaeovegetation maps enbled considerable detalization of knowledge about past vegetation in Lithuania. Consequently, main vegetation migration and distribution patterns were defined.

This study discusses the extent to which hunter-gatherer mobility strategies are changed by abrupt climate change events by monitoring changes in lithic assemblage compositions through the Pleistocene/Holocene Transition, from ca. 14,000 cal BP to 10,000 cal BP in northwest Europe, with a focus on the Younger Dryas Stadial event, which occurred around 12,900 cal BP to 11,700 cal BP. A set of predicted archaeological indicators were formed from existing theoretical models, based largely on Binford’s logistical and residential mobility model, with the expectation that a more residential mobility strategy would be used by hunter-gatherer-populations during warmer climatic phases (i.e. the Allerød and Preboreal) and a more logistical mobility strategy would be used during cold climatic phases (i.e. the Younger Dryas). The lithic assemblages from sites across northwest Europe were then compared with these expectations in order to determine if a shift from a more residential strategy to a more logistical strategy can be seen from the lithic record. Additionally, a further comparative dataset was collected from south Europe in order to determine if there were differences in the response to the Younger Dryas at lower latitudes where the impact of this event is assumed to be less severe. The results found that in northwest Europe there is evidence to suggest there was indeed a shift from a more residential strategy during the warm Allerød interstadial to a more logistical strategy during the Younger Dryas Stadial, and the adoption of a more residential strategy with the return of warmer conditions during the Preboreal. However, it appears that the Preboreal Interstadial shows significant differences between the Allerød Interstadial, with the Preboreal sharing more characteristics in common with the Younger Dryas. This has been interpreted as a response to the unstable climatic conditions reported from the environmental evidence in this region during the Preboreal, which may have limited the ability of hunter-gatherer populations to return to similar levels of residential mobility seen during the Allerød. The south Europe dataset provides evidence that the lesser impact of the Younger Dryas at lower latitudes brought about a more muted response by hunter-gatherer populations to this event when compared with the northwest. However, there appears to be a reversal of that seen in the northwest, with more logistically mobile populations during the Allerød and especially the Preboreal, and more residentially mobile populations during the Younger Dryas. This is despite the environmental evidence showing a very similar environmental response to the northwest, with a distinct opening of the landscape during the Younger Dryas. The apparent difference in mobility strategies appear to be more related to the available faunal species within a region and their behaviour within their environment rather than directly to the climate. In the south, species such as red deer and ibex are the main source of faunal subsistence throughout the Pleistocene/Holocene Transition, unchanged by shifts in temperature and environment, but the way in which hunter-gatherers would hunt such species would be expected to change in more wooded environments compared with more open environments. If we compare this with the northwest, there is evidence of a distinct change from hunted prey, such as red deer, during the Allerød and Preboreal, to reindeer and horse during the Younger Dryas (although faunal preservation is poor in this region). With this shift to a more mobile prey species, along with a harsher, more open environment it may be more suitable to practise a more logistical strategy. Additionally, the instability of the Preboreal may have also changed the environment on a smaller scale, which would have required the hunting of warmer climate prey in shifting local environments, much like that of the Younger Dryas in south Europe. This might explain the differences seen between the Allerød and the Preboreal. Overall, there appears to be strong evidence supporting the theory that colder, harsher climates promote a more logistically mobile response from hunter-gatherer populations as seen in the northwest of Europe, and that there was a more muted, different response to the Younger Dryas in the lower latitudes of south Europe. However, it is the opinion here that changes in human mobility are not controlled directly be climatic conditions, rather controlled by the available major prey species and their behaviour in changing environments.