Sökning: "clear-water lakes"
Visar resultat 1 - 5 av 15 avhandlingar innehållade orden clear-water lakes.
1. Carbon metabolism in clear-water and brown-water lakes
Sammanfattning : The trophic state of lakes is commonly defined by the concentration of nutrients in the water column. High nutrient concentrations generate high phytoplankton production, and lakes with low nutrient concentrations are considered low-productive. LÄS MER
2. Food Quality for Zooplankton in Humic Lakes
Sammanfattning : Food quality affects growth, reproduction and community structure of zooplankton, and has implications for nutrient cycling and the transfer of energy and matter in aquatic food chains. While the issue of food quality in clear water lakes has received great recent attention, studies on food quality for zooplankton in humic lakes are scarce. LÄS MER
3. Role of phagotrophy in freshwater phytoplankton
Sammanfattning : Some phytoplankton have the ability to combine phototrophy and heterotrophy within the same individual, which is called mixotrophy. In this thesis, I adress mixotrophy and competitive interactions of mixotrophs and obligate auto- or heterotrophs in relation to the availability of nutrients, light and prey. LÄS MER
4. Acidification trends in Swedish lakes : an assessment of past water chemistry conditions using lake sediments
Sammanfattning : This thesis presents temporal perspectives of lake acidification in Sweden. Sediment records have been used to study timing, trends and causes of acidification, and two different techniques for assessing past lake-water acidity are presented. LÄS MER
5. The palaeolimnological record of regime shifts in lakes in response to climate change
Sammanfattning : Regime shifts in lake ecosystems can occur in response to both abrupt and continuous climate change, and the imprints they leave in palaeolimnological records allow us to investigate and better understand patterns and processes governing ecological changes on geological time scales. This thesis aims at investigating palaeolimnological records of regime shifts in lakes during the Holocene to explore how lake ecosystems responded to climate changes and anthropogenic activities and to identify thresholds or tipping points that produced regime shifts. LÄS MER