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norskBrowsing Mastergradsoppgaver i biologi by Title
Now showing items 181-200 of 362
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Initial Community Convergence on Plant Defense Syndromes Explains Community Responses to Herbivore Exclosures
(Master thesis; Mastergradsoppgave, 2017-11-15)General trade-offs in species’ energy use are highlighted here by mapping proposed defense syndromes, using trade-offs found between: constitutive phenolic compounds, silica and a high nutrient low defense region found between regional con-specifics. Differences in species composition between two catchments can be explained by proposed syndrome trade-offs seeking energy use optimums in differing ... -
Initielle studier av Mll3104 og Mll3105 fra Mesorhizobium loti : proteiner antatt involvert i katabolisme av trehalose
(Master thesis; Mastergradsoppgave, 2007-12)Rhizobiacea utgjør en bakterieslekt der de fleste medlemmene er i stand til å inngå symbioser med diverse legumer. Slekten innbefatter Rhizobium, Sinorhizobium, Mesorhizobium, Bradyrhizobium og Azorhizobium, og kollektivt omtales disse for rhizobia. Partnerskapet med legumer er av mutualistisk karakter, der mikrosymbionten bidrar med fiksert nitrogen i form av NH3, og planteverten sørger for en ... -
Interactions between white-tailed eagle Haliaeetus albicilla, seabirds and tourism; how the breeding success of the endangered black-legged kittiwake Rissa tridactyla is affected
(Master thesis; Mastergradsoppgave, 2021-12-17)In many seabird colonies along the coast of Norway, the increased population of white-tailed eagle Haliaeetus albicilla and the growing industry of birdwatching tourism are causing a dilemma for management decisions. Thus, this study aimed to examine the indirect effect of white-tailed eagles and tourists on the breeding success of the endangered seabird species, black legged kittiwake Rissa tridactyla ... -
An interannual study of foraging behaviour in sympatrically breeding macaroni Eudyptes chrysolophus and chinstrap penguins Pygoscelis antarcticus at Bouvetøya
(Master thesis; Mastergradsoppgave, 2019-08-15)Species are likely to segregate their ecological niches to minimize competition for resources, but for centrally foraging predators that breed on sub-Antarctic islands in the Southern Ocean the possibility of niche segregation may be minimal. This study is the first to examine the spatial and trophic aspects of the foraging niche of sympatrically breeding macaroni and chinstrap penguins at the ... -
Interannual variability (2014-2019) of hydrography, fluorescence and nutrient distribution in Vestfjorden, Lofoten
(Master thesis; Mastergradsoppgave, 2020-06-01)Vestfjorden is an area of great ecological relevance since it is one of the main spawning areas of North East Atlantic cod. The survival rate of the cod larvae depends greatly on the abundance of zooplankton, which in turn depends on phytoplankton. Due to the extreme seasonality of high latitude fjords with a short productive season, understanding the phytoplankton distribution in spring is crucial. ... -
Investigating population genomic structure of salmon lice (Lepeophtheirus salmonis) in northern Norway
(Master thesis; Mastergradsoppgave, 2019-05-14)Salmon louse (Lepeophtheirus salmonis) is a parasitic copepod that causes significant damage to Atlantic salmon (Salmo salar) and incurs significant costs to the salmonid aquaculture industry. In Norway, the industry has been coping with salmon lice issues with various methods such as chemical treatments, but it has resulted in an acquisition of resistance in salmon lice towards the existing delousing ... -
Isolation and Characterization of Bacteriophages from the Arctic
(Master thesis; Mastergradsoppgave, 2023-05-14)Bacteriophages are viruses that specifically infect bacteria. These obligate intracellular parasites are Earth's most copious, ubiquitous, and genetically diverse (unexplored) biological entities. Organisms in the Arctic environment constantly experience extreme conditions, therefore life in the Arctic evolved different specialized strategies and molecules to survive which offers huge opportunities ... -
Isolation of Fungal Endophytes from Grasses by Laser Micro Dissection & Pressure Catapulting
(Master thesis; Mastergradsoppgave, 2013-12-12)A very diverse group of fungi capable of forming endophytic associations may have profound consequences for natural ecosystems as well as for cultivated plants. Fungal endophytes may benefit their host plants by producing secondary metabolites, and may be an important source for bioactive antimicrobial compounds, used in agriculture, commercial industry, and in medicine. Earlier studies on endophytes ... -
Kjønnsspesifikk overlevelse av unger hos gråmåke Larus argentatus og svartbak Larus marinus
(Master thesis; Mastergradsoppgave, 2008-03)Det er i dag gode bevis for at fugler har muligheter til å endre kjønn på avkom kjønns ratio) i forhold til en rekke miljøfaktorer. Dette kan skje enten ved at de produserer et overskudd av egg med unger av det ønskede kjønn (primær kjønns ratio), eller at de manipulerer kjønns ratio etter klekking ved å differensiere innvesteringa (eks. mating) i favør av det ene kjønnet sekundær kjønns ratio). ... -
Klimaeffekter på frøspiring og blomstring hos svalbardvalmue (Papaver dahlianum Nordh.)
(Master thesis; Mastergradsoppgave, 2007-05)Det ble gjennomført klimakammerforsøk på arten Papaver dahlianum, for å undersøke i hvilken grad klima påvirker frøspiring og blomstring hos avkommet. Høsten 2005 ble frø av Papaver dahlianum polare samlet rundt Longyearbyen og i Arktisk-alpin botanisk hage i Tromsø. Plantene i botanisk hage stammet også fra Svalbard, men ble sådd i Tromsø i 2002. Forsøkene ble utført ved Biologisk klimalaboratorium ... -
Langtidsstudie av næringsøkologi og vekst hos storørret i Pasvikvassdraget - en sammenligning mellom utsatt og vill ørret
(Master thesis; Mastergradsoppgave, 2014-05-15)Kraftutbyggingen i Pasvikvassdraget startet i 1964 og det finnes syv kraftverk i vassdraget. Storørretbestanden gikk kraftig tilbake som følge av kraftutbyggingen og i 1979 ble det startet et utsettingsprogram av ørret i elva for å kompensere for reduksjonen i størrelsen av den naturlige populasjonen. I dag settes det årlig ut 5000 ørret større enn 25 cm. Dette langtidsstudiet omhandler diett og ... -
Let it glow! Adapting a method to detect microplastics in snow and evaluate the potential for long-range transport
(Master thesis; Mastergradsoppgave, 2020-05-31)Harmonization of methods in microplastics research is lacking; this is affecting the comparability of results and hindering reproducibility. Investigating microplastics in snow is a relatively new field of research, and it can be used to answer questions about long-range atmospheric transport of microplastics. In this thesis, snow sampling methods were combined with the dye, Nile Red, to develop a ... -
Life history strategies of a trimorphic population of Arctic charr (Salvelinus alpinus (L.)) in Skogsfjordvatn, northern-Norway
(Master thesis; Mastergradsoppgave, 2013-05-15)Polymorphisms are widespread throughout many different taxa of vertebrates. Discrete polymorphisms or morphs usually differentiate in morphology, ecology and life history, most likely driven by adaptations to different habitats and resources. For sympatric morphs to be able to maximize fitness in different niches and habitats, they may develop differences in several life history traits. Arctic charr ... -
Life-history strategies in two subarctic lakes with polymorphic Arctic charr Salvelinus alpinus L. populations. High across lakes stability in evolution of life-history strategies
(Master thesis; Mastergradsoppgave, 2018-05-13)Life history strategies of polymorphic Arctic charr in two sub-arctic lakes (Tårnvatn and Skøvatn) with similar environmental- and physiochemical conditions were studied. Disparities in life history traits may reflect ecological adaptations and is suggested an important factor in the incipient speciation process. In this region several lakes have polymorphic charr, and the designation of a fish to ... -
Lik vinterbeite, ulik produksjon og vektutvikling: Et demografistudie på tamrein (Rangifer Tarandus) i Finnmark
(Mastergradsoppgave; Master thesis, 2009-08)Tetthetsavhengig næringsmangel som fører til lave vekter og påfølgende minket rekruttering er et velkjent fenomen i reindriften i Finnmark. Forskjeller i vekt og produksjon i reindriften i Norge har blitt forklart med ulikheter i høstingsstrategier og vinterforhold. Imidlertid har det blitt viet mindre oppmerksomhet til hvordan ulike sommerbeiteforhold påvirker reproduksjon og vektutvikling. I dette ... -
Linking methane fluxes and oxidation rates to methane oxidizing bacteria in an Arctic terrestrial methane seep, Svalbard
(Master thesis; Mastergradsoppgave, 2020-05-29)Global warming has especially detrimental effects on Arctic regions. One major issue is permafrost thaw and sub-permafrost methane escape via surface seeps. While the mitigation potential of methane-consuming bacteria on marine pingo-like methane seeps is well described, terrestrial methane seeps are still understudied. Recently, open system pingos have gained attention as terrestrial methane seeps. ... -
Lipid content, composition and dynamics in northern marine diatoms. An experimental study using different analytical methods
(Master thesis; Mastergradsoppgave, 2014-11-20)In this study, the fluorophore Nile Red was used as a probe for lipid accumulation during nutrient stress in the diatom Coscinodiscus concinnus, and to quantify lipid concentration fluorometrically in 5 monocultures of northern diatoms. The results from the fluorometrical quantification were validated by solvent extraction and HPLC-MS analysis in Bergen. In addition, 17 monocultures of 7 species of ... -
Lipids and diapause in Calanus spp. in a high-Arctic fjord: state-dependent strategies? Tracking lipids through the polar night
(Master thesis; Mastergradsoppgave, 2010-11-15)Calanus copepods C. finmarchicus, C. glacialis and C. hyperboreus are keystone species in the Arctic marine ecosystem, constituting 70-90% of the zooplankton biomass. In high latitudes, the growing season is short and unpredictable, and the winter long and unproductive. These species have adapted flexible life histories, lipid accumulation, and a state of deep-water diapause to survive. Winter ... -
Livssyklus hos løpebiller (Coleoptera, Carabidae) i en temperaturgradient i Nord-Norge
(Master thesis; Mastergradsoppgave, 2007)Endringer i livssyklus hos løpebiller (Coleoptera, Carabidae) ble undersøkt langs en høydegradient i en subarktisk bjørkeskog i Nord-Norge, og funnene ble sammenlignet med studier som har blitt gjort av de samme artene på sørligere breddegrader. Av de 6 artene vi undersøkte var det kun en art som endret tidspunkt for reproduksjon med økende høyde. Patrobus assimilis hadde en interaksjon mellom ... -
Local variation in mountain birch spring phenology along an altitudinal gradient in northern coastal Fennoscandia
(Master thesis; Mastergradsoppgave, 2011-06-10)Currently there is a lack of spring phenology studies covering small-scale altitudinal gradients of mountain birch in coastal northern Fennoscandia, a region characterized by exceptionally high precipitation of snow, which gives reason to investigate the influence of snow cover on birch budburst in this area. Furthermore, ground phenology studies are today increasingly replaced by satellite data ...
