Sökning: "nitrogen fixation"
Visar resultat 11 - 15 av 80 avhandlingar innehållade orden nitrogen fixation.
11. Non-cyanobacterial nitrogen fixation insights in humic freshwater lakes and ponds
Sammanfattning : The biological basis of nitrogen fixation beyond the canonical role of Cyanobacteria is not well understood in freshwater ecosystems. To address this gap in knowledge, the main objective of this thesis is to study non-cyanobacterial nitrogen fixation in freshwater lakes and ponds. LÄS MER
12. Filamentous cyanobacteria in the Baltic Sea - spatiotemporal patterns and nitrogen fixation
Sammanfattning : Summer blooms of filamentous, diazotrophic cyanobacteria are typical of the Baltic Sea Proper, and are dominated by Aphanizomenon sp. and the toxic Nodularia spumigena. Although occurring every summer, the blooms vary greatly in timing and spatial distribution, making monitoring difficult and imprecise. LÄS MER
13. Nutrient cycling in agroecosystems: nitrogen cycling in southern Sweden in the 1850s and two Tanzanian villages in the 1990s
Sammanfattning : This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. LÄS MER
14. Strategic nitrogen management in stockless organic cropping systems : redistribution of residual biomass for improved energy and nitrogen balance
Sammanfattning : Agriculture faces the challenge of producing high yields to feed a growing world population, while simultaneously addressing environmental problems such as eutrophication, emissions of greenhouse gases, loss of biodiversity and soil degradation. Organic farming can be part of the solution, as it promotes biodiversity, uses less energy for fertiliser production and often has higher inputs of organic matter to soil than conventional farming. LÄS MER
15. Functional genomics of the Baltic Sea cyanobacterium Nodularia spumigena in relation to nitrogen fixation, heterocyst differentiation and toxin production
Sammanfattning : Nodularia spumigena is a filamentous, heterocystous cyanobacterium that dominates the annual, toxic cyanobacterial blooms in the Baltic Sea. The blooms are believed to have increased in recent years, due to eutrophication by phosphate and/or nitrogen. Toxicity of these blooms is well-documented and attributed to the hepatotoxin nodularin. LÄS MER