Sökning: "periphyton"
Visar resultat 16 - 20 av 20 avhandlingar innehållade ordet periphyton.
16. The importance of predation in benthic stream communities
Sammanfattning : There has been considerable debate whether or not predators has any significant effects on prey densities in streams. This thesis examines the importance of predation in stream communities. I have conducted both field and laboratory studies where I have studied how both vertebrate and invertebrate predators affects benthic prey. LÄS MER
17. 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
18. Structuring factors for macroinvertebrate communities and the importance for ecosystem processing
Sammanfattning : Aquatic macroinvertebrates play important roles in our ecosystems and are essential for the ecosystem processing. An improved knowledge of structuring factors, such as competition and predation, and the way in which they operates in the macroinvertebrate community is crucial for our understanding of not only the macroinvertebrates but also the ecosystem in general. LÄS MER
19. Species interactions in streams - effects of predation, competition and ecosystem properties
Sammanfattning : Stream ecosystems are dynamic and they have an inherent environmental variability. Organisms that live in streams are adapted to the continuously changing environment and the presence or absence of species are determined by their environmental requirements, while abundance is most often affected by interactions, such as competition and predation, with other species that are found in the same habitat. LÄS MER
20. Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments
Sammanfattning : This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. LÄS MER