Sökning: "Lakes"
Visar resultat 21 - 25 av 381 avhandlingar innehållade ordet Lakes.
21. Persistent organic pollutants in benthic foodwebs
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
22. Microbial evolution: patterns of diversity in aquatic protists
Sammanfattning : Little is known about how microbes diversify in nature. In contrast to the more studied multicellular organisms, microbes can have a) huge population sizes, b) high reproductive rates and c) long-distance dispersal. These characteristics can affect their tempo and mode of diversification in ways that still need to be understood. LÄS MER
23. The importance of terrestrial carbon in plankton food webs
Sammanfattning : Allochthonous substances, i.e. produced in terrestrial ecosystems, are known to fuel bacterial production in humic lakes. I observed that allochthonous carbon subsidizes bacteria even at high levels of phytoplankton biomass. LÄS MER
24. Dissolved organic matter in lakes : Chemical diversity and continuum of reactivity
Sammanfattning : Dissolved organic matter (DOM) is the largest pool of organic carbon in aquatic systems and an important component of the global carbon cycle. Large amounts of DOM are decomposed within lakes, resulting in fluxes of CO2 and CH4 to the atmosphere. LÄS MER
25. Acidification trends in Swedish lakes : an assessment of past water chemistry conditions using lake sediments
Sammanfattning : This thesis presents temporal perspectives of lake acidification in Sweden. Sediment records have been used to study timing, trends and causes of acidification, and two different techniques for assessing past lake-water acidity are presented. LÄS MER