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Visar resultat 1 - 5 av 24 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Effects of climate change on boreal wetland and riparian vegetation

   Författare :Lotta Ström; Roland Jansson; Christer Nilsson; Sarah Gergel; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biomass; flooding; hydrologic niche; invasibility; riparian zone; riparian plant species; river margin; climate scenario; seed sowing experiment; species composition; species richness; transplant experiment; Terrestrial ecology; Terrestrisk ekologi;

   Sammanfattning : Models of climate change predict that temperature will increase during the 21th century and the largest warming will take place at high northern latitudes. In addition to warming, predictions for northern Europe include increased annual precipitation and a higher proportion of the precipitation during winter falling as rain instead of snow. LÄS MER

3. 2. Hydrogeochemical effects of hydropower regulation on river-aquifer continuum in boreal rivers

   Författare :Dmytro Siergieiev; Hjalmar Laudon; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geochemistry; hyporheic zone; hydrology; riparian zone; Element transport; Lule River; Kalix RIver; Northern Sweden; Earth sciences; Applied Geology; Tillämpad geologi;

   Sammanfattning : Hydropower infrastructure affects many large rivers worldwide, threatening riverine and coastal ecosystems by fragmenting flow, disturbing landscapes and water retention and altering sedimentation and primary production. This thesis investigated major impacts of hydropower regulation on hydrological and geochemical processes in large boreal rivers. LÄS MER

4. 3. Water quality modeling based on landscape analysis: importance of riparian hydrology

   Författare :Thomas Grabs; Jan Seibert; Kevin Bishop; Hjalmar Laudon; Brian McGlynn; Georgia Destouni; Irena Creed; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Water quality model; terrain analysis; geographical information system GIS; riparian zone; total organic carbon TOC; boreal catchments; Hydrology; Hydrologi; geografi med naturgeografisk inriktning; Physical Geography;

   Sammanfattning : Several studies in high-latitude catchments have demonstrated the importance of near-stream riparian zones as hydrogeochemical hotspots with a substantial influence on stream chemistry. An adequate representation of the spatial variability of riparian-zone processes and characteristics is the key for modeling spatio-temporal variations of stream-water quality. LÄS MER

5. 4. Ice, wood and rocks : regulating elements in riverine ecosystems

   Författare :Johanna Engström; Christer Nilsson; Roland Jansson; James Helfield; Tenna Riis; Umeå universitet; []
   Nyckelord :riparian zone; timber floating; river restoration; cut-off side channels; hydrochory; large wood; anchor ice; fish;

   Sammanfattning : Riparian ecosystems are of great importance in the landscape, connecting landscape elements longitudinally and laterally and often encompassing sharp environmental gradients in ecological processes and communities. They are influenced by fluvial disturbances such as flooding, erosion and sediment deposition, which create dynamic and spatially heterogeneous habitats that support a high diversity of species. LÄS MER

7. 5. Characterisation of PFASs and Organofluorine in Freshwater Environments : Transfer from water to land via emergent aquatic insects

   Författare :Alina Koch; Thanh Wang; Micael Jonsson; Leo W. Y. Yeung; Anna Kärrman; Lutz Ahrens; Jonathan Martin; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PFASs; riparian zone; emergent aquatic insects; terrestrial consumers; stable isotopes; organofluorine mass balance; AFFF; point sources;

   Sammanfattning : Per- and polyfluoroalkyl substances (PFASs) are anthropogenic contaminants of emerging concern, because many are highly persistent to degradation and have been linked to adverse effects in humans as well as their ubiquitous spread in aquatic environments. This thesis investigated distribution of PFASs and organofluorine in freshwater environments impacted by PFAS point sources. LÄS MER