Sökning: "Ulf Båmstedt"

Hittade 4 avhandlingar innehållade orden Ulf Båmstedt.

1. 1. Food web structures and carbon transfer efficiencies in a brackish water ecosystem

   Författare :Kristin Dahlgren; Ulf Båmstedt; Agneta Andersson; Marja Koski; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon transfer efficiency; Food web efficiency; zooplankton; production; pelagic; benthic; fatty acids; wax esters; Marine ecology; Marin ekologi;

   Sammanfattning : Two differently structured food webs can be distinguished in the pelagic habitat of aquatic systems; the classical one (autotrophic) with phytoplankton as a base and the microbial food web (heterotrophic) with bacteria as a base. Energy (produced at the basal trophic level) reaches higher trophic levels, i.e. LÄS MER

3. 2. Effects of temperature and terrestrial carbon on fish growth and pelagic food web efficiency

   Författare :Robert Lefébure; Ulf Båmstedt; Pär Byström; Stefan Larsson; Agneta Andersson; Lars-Gösta Rudstam; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attack rates; Bacterial production; Climate change; Critical resource density; Growth rates; Microbial food web; Three-spined stickleback;

   Sammanfattning : Both temperature and terrestrial dissolved organic carbon (TDOC) have strong impacts on aquatic food web dynamics and production. Temperature affects vital rates of all organisms and terrestrial carbon has been shown to alter the dynamics of phytoplankton and bacterial production and affect the trophic structure of planktonic food webs. LÄS MER

4. 3. Copepods in Skeletonema-dominated food webs : Toxicity and nutritional quality as factors controlling copepod-diatom interactions

   Författare :Roswati Md Amin; Ulf Båmstedt; Sigrun Jónasdóttir; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Copepod-diatom interaction; toxicity; nutritional quality; Skeletonema;

   Sammanfattning : My thesis focuses on copepod-diatom interactions, specifically on the effects of food quality and toxicity on copepod feeding, reproductive success and behavior but as a frame, also includes a quantitative evaluation of copepod carbon requirements compared to other trophic plankton groups. My aim was to evaluate the function of copepods in diatom-dominated spring blooms. LÄS MER

5. 4. Experimental Studies on the Regulation of Pigment Dynamics in Phytoplankton and Copepods by Dissolved Inorganic Nutrients

   Författare :Lies Van Nieuwerburgh; Pauli Snoeijs; Ulf Båmstedt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Astaxanthin; Baltic Sea; carotenoids; diatoms; eutrophication; food web; mesocosms; microalgae; M74 syndrome; oxidative stress; phytoplankton blooms; zooplankton; Biologi; Biology; Biologi;

   Sammanfattning : This thesis examines the role of dissolved inorganic nutrients in generating changes in phytoplankton community and pigment composition and if such changes can affect the production of the antioxidant astaxanthin in the ecosystem via pelagic copepods. The background of my studies is the possible relationship between eutrophication and a reproductive disturbance in Baltic populations of Atlantic salmon (M74), which is associated with astaxanthin and thiamine deficiencies and oxidative stress. LÄS MER