Search for dissertations about: "Cladocera"

Found 5 swedish dissertations containing the word Cladocera.

2. 1. Long-term development of subalpine lakes : effects of nutrients, climate and hydrological variability as assessed by biological and geochemical sediment proxies

   Author : Manuela Milan; Christian Bigler; Monica Tolotti; Richard Bindler; Krystyna Szeroczyńska; Atte Korhola; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Paleolimnology; diatoms; Cladocera; sub-fossil pigments; geochemistry; wavelengthdispersive X-ray fluorescence spectroscopy; Lake Garda; Lake Ledro; reference conditions; nutrient enrichment; climate change; hydrological regime.;

   Abstract : Sediment records of two Italian subalpine lakes (Lake Garda and Lake Ledro) were analyzed in order to reconstruct their ecological evolution over the past several hundred years. A multi-proxy and multi-site approach was applied in order to disentangle the effects of local anthropogenic forcings, such as nutrients, and climate impacts on the two lakes and their catchments. READ MORE

4. 2. Food Quality Effects on Zooplankton Growth and Energy Transfer in Pelagic Freshwater Food Webs

   Author : Jonas Persson; Tobias Vrede; Peter Eklöv; Ellen van Donk; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; elemental stoichiometry; phosphorus; polyunsaturated fatty acids; EPA; oligotrophic lakes; empirical modelling; Daphnia; Cladocera; Copepoda; Ekologi;

   Abstract : Poor food quality can have large negative effects on zooplankton growth and this can also affect food web interactions. The main aims of this thesis were to study the importance of different food quality aspects in Daphnia, to identify potentially important differences among zooplankton taxa, and to put food quality research into a natural context by identifying the importance of food quality and quantity in lakes of different nutrient content. READ MORE

5. 3. Daphnids adaptive strategies to UV radiation

   Author : Carla Eloisa Fernández; Avdelningen för Teknisk vattenresurslära; []
   Keywords : Cladocera; Zooplankton; Andean lakes; Daphnia; Ultraviolet radiation; Migration strategy; Photo-protection;

   Abstract : This thesis focuses on the adaptive strategies of daphnids that allows them to maintain stable populations while deal with UV radiation, highlighting the differences in the responses that populations with different evolutionary histories may have.Although exposition to lethal doses in nature is unlikely, sub-lethal UV-B radiation doses may have strong impacts on zooplankton. READ MORE

6. 4. The role of crustacean zooplankton in pelagic nutrient cycling

   Author : Tobias Vrede; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; nutrients; freshwaters; food web; Cladocera; Calanoida; stoichiometry; Biologi; Biology; Biologi; limnologi; Limnology;

   Abstract : Herbivorous crustacean zooplankton link phytoplankton and other microorganisms withhigher trophic levels in pelagic food webs. Crustaceans show little intraspecificvariation in somatic C:N:P elemental ratios, which may have implications for theregulation of zooplankton growth and for nutrient cycling. READ MORE

7. 5. On the evolutionary effects of linkage and deleterious mutations in small populations

   Author : Snæbjörn Pálsson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Breeding systems; Daphnia pulex; deleterious mutations; linkage; neutral variation; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; Genetics; genetik;

   Abstract : The aim of this thesis is to evaluate the effect of deleterious mutations and linkage on variation in neutral markers and fitness in small populations. The study is based on two main approaches, one by using computer simulations, the other by exploring genetic variation in a cyclical parthenogen, Daphnia pulex (Crustacea: Cladocera). READ MORE