Sökning: "δ15n"

Visar resultat 1 - 5 av 20 avhandlingar innehållade ordet δ15n.

  1. 1. Varved lake sediments and diagenetic processes

    Författare :Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

    Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER

  3. 2. The impact of cormorant nesting colonies on plants and arthropods

    Författare :Gundula S. Kolb; Peter Hambäck; Lenn Jerling; Post David; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; seabirds; cormorants; islands; nitrogen; phosphorus; plants; arthropods; δ15N; Baltic Sea; ecological stoichiometry; species richness; species composition; numeric response; Biology; Biologi; Plant Ecology; växtekologi;

    Sammanfattning : Seabirds concentrate large amounts of marine nutrients on their nesting islands. This nutrient input can have large consequences for island food webs and community structure. The high nutrient load may also cause runoff into surrounding waters and affect marine communities. LÄS MER

  4. 3. Migration in Prehistory : DNA and stable isotope analyses of Swedish skeletal material

    Författare :Anna Linderholm; Kerstin Lidén; Oliver Craig; Stockholms universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; Migration; ancient DNA; stable isotopes; δ13C; δ15N; δ34S; mtDNA; lactose tolerance; Neolithic; Pitted Ware culture; Funnel Beaker culture; Vikings; Öland; Rössberga; Birka; Björned; Archaeology; Arkeologi; Archaeological Science; laborativ arkeologi;

    Sammanfattning : The main aim of this thesis is to show how scientific methods may be used to look at migration in prehistory on the basis of archaeological material. The individuals examined represent the period 4 000 BC to 1 000 AD and have their geographical origins in various parts of Sweden.Ancient DNA analysis is employed in three cases. LÄS MER

  5. 4. Consuming and communicating identities : Dietary diversity and interaction in Middle Neolithic Sweden

    Författare :Elin Fornander; Kerstin Lidén; Per Andersson; Liv Nilsson Stutz; Stockholms universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; Middle Neolithic; Neolithisation; Sweden; Baltic Sea; Funnel Beaker Culture; Pitted Ware Culture; Battle Axe Culture; megaliths; isotopes; δ13C; δ15N; δ34S; 87Sr 86Sr; radiocarbon dating; palaeodiet; mobility; interaction; identity; ethnicity; Archaeology; Arkeologi; Archaeological Science; laborativ arkeologi;

    Sammanfattning : Isotope analyses on human and faunal skeletal remains from different Swedish Neolithic archaeological contexts are here applied as a means to reconstruct dietary strategies and mobility patterns. The chronological emphasis is on the Middle Neolithic period, and radiocarbon dating constitutes another central focus. LÄS MER

  7. 5. Nitrate stable isotopes and major ions in snow and ice from Svalbard

    Författare :Carmen Paulina Vega Riquelme; V. A. Pohjola; R. Pettersson; E. Isaksson; C. E. Bøggild; Kumiko Goto-Azuma; Uppsala universitet; []
    Nyckelord :nitrate stable isotopes; nitrate; NOx proxies; ice cores; percolation; ion relocation; Svalbard; stabila isotoper av nitrat; nitrat; indikator för kväveoxider; iskärnor; perkolation; joniska omlokalisering; Svalbard; Earth Science with specialization in Physical Geography; Geovetenskap med inriktning mot naturgeografi;

    Sammanfattning : Increasing atmospheric reactive nitrogen (Nr), as consequence of human activities, has generated accumulation of nitrate (NO3-) in Arctic regions. The Arctic has fragile nitrogen limited ecosystems that can be altered by increases of dry or wet deposition of Nr. LÄS MER