Sökning: "predation impact"

Visar resultat 1 - 5 av 42 avhandlingar innehållade orden predation impact.

  1. 1. Bacteria that escape predation : waterborne pathogens and their relatives

    Författare :Karolina I. A. Eriksson; Agneta Andersson; Johanna Thelaus; Jon Ahlinder; David Sundell; Klaus Jürgens; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bacterial pathogens; protozoa; predation resistance; aquatic microbiology; climate change; opportunists; humification; iron; environmental science; miljövetenskap; mikrobiologi; Microbiology;

    Sammanfattning : The hidden presence of opportunistic bacterial pathogens in the environment evokes concerns about emerging diseases, especially in the light of climate change. The co-evolution of bacteria and their predators (protozoa) has led to bacterial defence strategies of which some contribute to the ability of bacteria to cause disease. LÄS MER

  3. 2. The importance of predation in benthic stream communities

    Författare :Jonas Dahl; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ekologi; Ecology; invertebrate predators; vertebrate predators; Predation; streams;

    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

  4. 3. Effects of Great Cormorant Predation on Fish Populations and Fishery

    Författare :Henri Engström; Sture Hansson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Great Cormorant; Phalacrocorax carbo sinensis; predation; population regulation; diet; diet preferences; eel; behavioural responses; bird-fishery conflicts; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Sammanfattning : The strong increase in number of Great cormorants Phalacrocorax carbo in Sweden in recent years has led to conflicts - particularly with fishery. This thesis focuses on the possible effects of cormorant predation on fish populations. LÄS MER

  5. 4. Long Term Studies of Insect Abundances in Temporary Wetlands in Relation to Hydrology, Predation and Bti

    Författare :Thomas Persson Vinnersten; Jan O Lundström; Örjan Östman; William Walton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; floodwater mosquitoes; mosquito control; predation; aquatic insects;

    Sammanfattning : Long-term insect abundances have been studied to investigate factors structuring the insect communities of the temporary wetlands around the River Dalälven floodplain. In the wet meadows and swamps in the River Dalälven floodplains recurrent floods are the ultimate prerequisite for high production of floodwater mosquitoes. LÄS MER

  7. 5. Environmental factors selecting for predation resistant and potentially pathogenic bacteria in aquatic environments

    Författare :Peter Mathisen; Agneta Andersson; Johanna Thelaus; Mats Forsman; Anders Sjöstedt; Tron Frede Thingstad; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eutrophication; productivity; predation pressure; predation-resistant bacteria; pathogens; Francisella tularensis; adaptation; biomarker; oligotyping;

    Sammanfattning : The long history of co-existence of bacteria and their protozoan predators in aquatic environments has led to evolution of protozoa resistant bacteria (PRB). Many of these bacteria are also pathogenic to humans. LÄS MER