Search for dissertations about: "peat history"

Showing result 1 - 5 of 14 swedish dissertations containing the words peat history.

2. 1. Holocene dynamics in subarctic peat plateaus of west-central Canada : Vegetation succession, peat accumulation and permafrost history

   Author : A. Britta K. Sannel; Peter Kuhry; Peter Jansson; Ian Brown; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; peatlands; permafrost; carbon accumulation; fire; subarctic; Holocene; Physical geography; Naturgeografi;

   Abstract : Dynamics in vegetation, permafrost and peat and net carbon accumulation rates throughout the Holocene have been studied in two subarctic peat plateaus of west-central Canada through plant macrofossil analysis, geochemical analyses and AMS radiocarbon dating. Peatland formation at the studied sites began around 6600-5900 cal yr BP as a result of paludification of upland forests. READ MORE

4. 2. Subarctic ecosystem responses to climate, catchment and permafrost dynamics in the Holocene

   Author : Ulla Kokfelt; Kvartärgeologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; subarctic Sweden; palsa mire development; peat; permafrost history; carbon and nutrient cycling; lake sediments;

   Abstract : This thesis assesses aspects of the wetland development, permafrost dynamics and associated changes in carbon and nutrient cycling of the Stordalen Mire in northern Sweden. Various ecological and biogeochemical analyses of one peat and two lake sediment sequences were conducted, including analyses of organic matter and carbonate content, mosses, diatoms, testate amoebae, pigments, carbon and nitrogen and their stable isotopes, near infrared spectroscopy and biogenic silica. READ MORE

5. 3. Temporal and spatial dynamics in subarctic peat plateaus and thermokarst lakes

   Author : A. Britta K. Sannel; Peter Kuhry; Peter Jansson; Ian A. Brown; Serge Payette; Stockholms universitet; []
   Keywords : Peatlands; permafrost; subarctic; peat plateau; thermokarst lake; macrofossil analysis; carbon nitrogen ratio; peat accumulation; carbon accumulation; remote sensing; binary encoding; time-series analysis; Physical Geography; naturgeografi;

   Abstract : Permafrost peatlands are widespread at high northern latitudes and are important soil organic carbon reservoirs. A future warming in these areas, as suggested by global climate models, can cause thawing and increased ground subsidence (thermokarst), resulting in changes in surface hydrology and ecosystem functioning. READ MORE

6. 4. Fire history in the hemiboreal and southern boreal zones of southern Sweden during 11000 years : Relationships with past vegetation composition and human activities and implications for biodiversity issues

   Author : Qiao-Yu Cui; Marie-José Gaillard; Boris Vannière; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fire history; land-use history; biodiversity; charcoal analysis; Landscape Reconstruction Algorithm LRA ; Holocene; Småland; Sweden; Paleoecology; Paleoekologi;

   Abstract : This thesis studies fire history over the last 11 000 years (Holocene) in central Småland, southern Sweden, on the basis of palaeoecological analyses of peat sequences from three small bogs (Notteryd, Stavsåkra and Storasjö). The main objective is to gain insights into the long-term relationships between fire, climate, human-impact, other environmental factors and the history of biodiversity in the study region. READ MORE

7. 5. Paleoenvironmental and paleoclimatic changes in northeast Thailand during the Holocene

   Author : Sakonvan Chawchai; Barbara Wohlfarth; Richard Bindler; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Paleoenvironment; paleoclimatic; sediment; peat; multi-proxy; Asian monsoon; the Holocene; Marine Geology; maringeologi;

   Abstract : The long-term climatic and environmental history of Southeast Asia is still fragmentary. This thesis therefore aims at studying lake sediment/peat sequences using a multi-proxy approach to reconstruct the environmental history and the impact of past changes in monsoon variability and intensity on lake ecosystems in Thailand. READ MORE