Sökning: "nutrients"

Visar resultat 21 - 25 av 686 avhandlingar innehållade ordet nutrients.

1. 21. Macroalgae in the Baltic Sea : responses to low salinity and nutrient enrichment in Ceramium and Fucus

   Författare :Lena Bergström; Lars Ericson; Lena Kautsky; Erik Bonsdorff; Christine A Maggs; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; adaptation; asexual reproduction; Baltic Sea; Gulf of Bothnia; salinity; macroalgae; nutrients; sexual reproduction; stress; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : The brackish Baltic Sea is a marginal environment for both marine and freshwater species. The rate of ecological differentiation is presumably high due to strong selection pressure from a gradient of decreasing salinity that has been present in its current state for only about 3 000 years. LÄS MER

3. 22. Long-term development, modeling and management of nutrient loading to inland and coastal waters

   Författare :Amelie Darracq; Georgia Destouni; Andrea Rinaldo; Stockholms universitet; []
   Nyckelord :Nutrients; catchments; environmental management; climate change; population and lifestyle development; subsurface-surface water interactions; long-term simulations; nutrient retention; modeling; hydrology; transport processes; biogeochemistry; scaling; transport and reaction rates; Physical Geography; geografi med naturgeografisk inriktning;

   Sammanfattning : Environmental and water system protection and restoration require accurate knowledge and quantification of waterborne pollutant transport, retention-release and transformation processes taking place in the subsurface, river, lake and sea water systems, and at the interfaces between these systems. This thesis investigates the importance of spatial model resolution for such quantification and the possible long-term nutrient load development under different human perturbations and nutrient source management scenarios in the Swedish Norrström drainage basin, based on simulations with the GIS-based dynamic nutrient transport-attenuation model POLFLOW. LÄS MER

4. 23. Predictive Modelling of Aquatic Ecosystems at Different Scales using Mass Balances and GIS

   Författare :Andreas Gyllenhammar; Lars Håkanson; Lars Brydsten; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; mass balance model; dynamic model; scales; marine fish farms; rainbow trout; nutrients; suspended particulate matter; phosphorus; nitrogen; GIS; basin delineation; regionalisation; coastal areas; aquatic foodweb; fishing quotas; Baltic Sea; Archipelago Sea; Okavango Delta; Geovetenskap; Earth sciences; Geovetenskap;

   Sammanfattning : This thesis presents models applicable for aquatic ecosystems. Geographical Information Systems (GIS) form an important part of the thesis. The dynamic mass balance models focus on nutrient fluxes, biotic/abiotic interactions and operate on different temporal and spatial scales (site, local, regional and international). LÄS MER

5. 24. Persistent organic pollutants in benthic foodwebs

   Författare :Niklas Holmqvist; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; Intraspecific interactions; streams; nutrients; lakes; crayfish; eels; Persistent organic pollutants; Benthic foodwebs; akvatisk ekologi; Environmental chemistry; Miljökemi;

   Sammanfattning : Concentrations of persistent organic pollutants (POPs) in aquatic biota are dependent on several factors both on individual and on system level. Bioaccumulation of POPs in pelagic biota in lakes as well as fish in streams has been shown to be dependent on nutrient regime of the system. LÄS MER

7. 25. Phytophthora and Oak Decline - Impact on Seedlings and Mature Trees in Forest Soils

   Författare :Ulrika Jönsson Belyazid; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; microbial competition; carbon allocation; nutrients; water availability; soil chemistry; mature oaks; seedlings; acid soils; Phytophthora quercina; Quercus robur;

   Sammanfattning : This thesis investigated the occurrence of soilborne species of the plant pathogenic genus Phytophthora in southern Swedish oak forests and their possible involvement in southern Swedish oak decline. The emphasis was on the impact of P. quercina on Quercus robur in acid forest soils. LÄS MER