Sökning: "Biologi"
Visar resultat 21 - 25 av 6263 avhandlingar innehållade ordet Biologi.
21. Ecology across Boundaries : Food web coupling among and within ecosystems
Sammanfattning : Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. LÄS MER
22. Forest-stream linkages : Experimental studies of foraging and growth of brown trout (Salmo trutta L)
Sammanfattning : Riparian vegetation along streams and rivers affects the aquatic community in numerous ways and often operates as a link for energy flux between forest and streams. The studies presented in this licentiate thesis focus on light and terrestrial invertebrates, two factors influenced by riparian zone structure, which potentially affect stream ecosystems and thus also brown trout (Salmo trutta). LÄS MER
23. The Macroinvertebrate Community in a Nature-like Fishway with Habitat Compensation Properties
Sammanfattning : Nature-like fishways are often constructed to restore connectivity in streams exploited for hydropower. They also have the potential to compensate for important habitats that have been degraded or lost. LÄS MER
24. Population ecology of perch (Perca fluviatilis) in boreal lakes
Sammanfattning : I studied the effects of temperature, pH, competition and predation on Eurasian perch (Perca fluviatilis) in 30 lakes in Norway during 1981-2001. The study lakes were situated in two different areas in southern Norway; four lakes in Aust-Agder county in southernmost Norway were explored during 1981-1984 and 26 lakes in Hedmark county in south-eastern Norway were investigated during 1992-2001. LÄS MER
25. Jurassic and Early Cretaceous selachians - focus on southern Scandinavia
Sammanfattning : .... LÄS MER