Search for dissertations about: "stable carbon and nitrogen isotopes"

Showing result 1 - 5 of 21 swedish dissertations containing the words stable carbon and nitrogen isotopes.

2. 1. Quantity and quality of soil organic matter in permafrost terrain

   Author : Gustaf Hugelius; Peter Kuhry; Philip Wookey; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; carbon; soil organic matter; soil organic carbon; permafrost; arctic; upscaling; peat plateau; cryoturbation; active layer; thermokarst; carbon nitrogen ratio; stable isotopes; humification; Physical geography; Naturgeografi; geografi med naturgeografisk inriktning; Physical Geography;

   Abstract : High latitude terrestrial ecosystems are considered key components in the global carbon (C) cycle and hold large reservoirs of soil organic carbon (SOC). Much of this is stored as soil organic matter (SOM) in permafrost soils and peat deposits and is vulnerable to remobilization under future global warming. READ MORE

4. 2. Varved lake sediments and diagenetic processes

   Author : Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

5. 3. Norm and difference : Stone Age dietary practice in the Baltic region

   Author : Gunilla Eriksson; Kerstin Lidén; Birgit Arrhenius; Michael Richards; Stockholms universitet; []
   Keywords : HUMANIORA; HUMANITIES; diet; norm; variation; Mesolithic; Neolithic; Sweden; Latvia; stable carbon and nitrogen isotopes; radiocarbon; reservoir effect; dogs; breastfeeding; gender; Archaeology subjects; Arkeologiämnen;

   Abstract : Stone Age research on Northern Europe frequently makes gross generalizations about the Mesolithic and Neolithic, although we still lack much basic knowledge on how the people lived. The transition from the Mesolithic to the Neolithic in Europe has been described as a radical shift from an economy dominated by marine resources to one solely dependent on farming. READ MORE

6. 4. Effects of heavy metal contamination on carbon and nitrogen cycling : An ecological approach to assess risks to soil functions

   Author : Ingrid Rijk; Alf Ekblad; Dan Berggren Kleja; Erik Karltun; Örebro universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; heavy metals; soil contamination; stable isotopes; N cycling microbial guilds; 13C; 15N; nitrification; denitrification; biochar; soil respiration; microbial activity; bioavailability;

   Abstract : Soil contamination with heavy metals may disrupt soil microorganisms with important roles in carbon (C) and nitrogen (N) cycling. However, there is a lack of understanding on how microorganisms are affected in soil, which may lead to a mismatch when assessing risks of contaminants to field soils. READ MORE

7. 5. An evaluation of the distributions of polychlorinated biphenyls and organic matter in coastal sediments

   Author : Anders Jönsson; Örjan Gustafsson; Detlef Schulz-Bull; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Polychlorinated biphenyls PCBs ; organic carbon; sediment; stable carbon isotopes; Earth sciences; Geovetenskap;

   Abstract : The objective of this thesis is to improve the understanding of what processes and mechanism affects the distribution of polychlorinated biphenyls (PCBs) and organic carbon in coastal sediments. Because of the strong association of hydrophobic organic contaminants (HOCs) such as PCBs with organic matter in the aquatic environment, these two entities are naturally linked. READ MORE