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Taxonomic, anatomical, and spatio-temporal variations in the stable carbon and nitrogen isotopic compositions of plants from an African savanna 总被引:5,自引:1,他引:4
Jacqui Codron Daryl Codron Julia A. Lee-Thorp Matt Sponheimer William J. Bond Darryl de Ruiter Rina Grant 《Journal of archaeological science》2005,32(12):1757-1772
Stable carbon (δ13C) and nitrogen (δ15N) isotope ratios are commonly used to reconstruct palaeodiets and palaeoenvironments. The method is based on our knowledge of isotopic patterns in plants, which are subject to taxonomic and environmental variability. While previous researchers have addressed isotopic variability amongst plants, no studies have looked extensively at a broad suite of taxa over multiple temporal scales from within the savanna biome so as to provide baseline data for palaeodietary and palaeoenvironmental studies. Here we document variations in the isotopic compositions of plants collected over two years from the Kruger National Park, South Africa, with respect to species and anatomical differences, and the influences of geological substrate and spatio-temporal shifts in climate. Results show that environmentally-induced carbon isotopic variations in plants within this region are generally smaller than 2‰, which is lower than what has been previously reported for plants compared across multiple habitat-types. These data suggest that δ13C differences of 2‰ or more (or 1‰ if the diet is predominantly C4) between animals from a given area reliably indicate real dietary differences. Plant δ15N values vary greatly between different microhabitats (by up to 4‰), responding to a range of environmental influences that may, in turn, significantly influence variation in animal δ15N values. 相似文献
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Producing the Future: Getting To Be British 总被引:1,自引:0,他引:1
Enduring struggles between different historical capitalisms are concretely instantiated in the British "colony" in Porto, Portugal. In contention is the future of the community and its identity as a venerable port merchant or multinational corporate enclave. Residents, both long- and short-term, work to produce the future place and identity of their children. Church, club, and—above all—schools are the focus of their clashes and also of this essay, as it explores the articulation of practices that help to produce those futures. 相似文献
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Jean Hillier 《Geographical Research》2003,41(3):251-269
This paper tells a story of environmental conflict and the attempted political resolution of issues of planning for native forests in Western Australia. It refers to the Western Australian Regional Forest Agreement and Draft Forest Management Plan processes to demonstrate how a range of actors utilise vari‐ous discourses and network relations in attempts to influence governmental decision‐making capacity. Adapting elements of a model of capacity‐building for environmental decision‐making, the paper indicates how traditional exclusionary decision networks serve to inhibit decision capacity, whilst more inclusive processes may be more likely to cope with challenges of reconciling multiple values and decision‐making for managing the forests in the interests of society as a whole. 相似文献
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The aim of the paper is to summarise the present state of knowledge concerning bitumen trade in the Near East from the Palaeolithic (70,000 BP) to the Early Islamic period. During the Palaeolithic and Early Neolithic period, bitumen utilisation was mostly concentrated in settlements close to oil seeps. From the Ubaid 3 period, bitumen from the Mosul area became more important and was traded as far as the southern Persian Gulf. The Uruk period is a turning point for Mesopotamian history as settlements evolved into city‐states. These cities had a great need for raw materials, and this marks the beginning of large‐scale exploitation of Hit bitumen. This bitumen was traded at settlements along the Euphrates, where a large trade network was established. Hit bitumen entered the Persian Gulf at the turn of the second millennium (Dilmun period). Bitumen from Iraq (Mosul and Hit) became predominantly used in most settlements along the southern coast of the Gulf. During this period Iranian bitumen was also exported and this supply tended to increase, especially during the Partho‐Sasanian period. Dead Sea bitumen had its own exchange network, which was concentrated across present‐day Israel and Egypt where it was extensively used for mummification. 相似文献
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Alfonso Benito-Calvo Jorge Martínez-Moreno Jesús F. Jord Pardo Ignacio de la Torre Rafael Mora Torcal 《Journal of archaeological science》2009,36(11):2566-2577
The comparative study of sedimentary fabrics in relation to archaeological fabrics in various levels of the sites of Cova Gran de Santa Linya (Middle and Early Upper Palaeolithic) and the Roca dels Bous (Middle Palaeolithic) has made it possible to analyse the formation dynamics of the deposits and determine the extent of disturbance of the archaeological levels by natural processes. To achieve this, diagrams and two- and three-dimensional indices were calculated from the azimuth and dip angle of natural clasts and artefacts. The results indicate that the sedimentary levels were formed mainly by planar fabric shape gravitational processes (low depositional angles), which differ notably from the archaeological fabrics they contain, characterised by a greater degree of isotropy. This difference in the fabrics would reflect human activity and indicates that the archaeological levels both in Cova Gran and Roca dels Bous have not been subject to significant natural modifications, and are preserved in situ. 相似文献
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