Search for dissertations about: "Lemmus lemmus"

Showing result 1 - 5 of 10 swedish dissertations containing the words Lemmus lemmus.

2. 1. Predator responses to non-stationary rodent cycles

   Author : Peter Hellström; Anders Angerbjörn; Xavier Lambin; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Buteo lagopus; Vulpes lagopus; Lemmus; Myodes; population cycles; predation; numerical response; functional response; arctic; lemmings; voles; fox; monitoring; raptors; zoologisk ekologi; Animal Ecology;

   Abstract : Regular fluctuations in population size, cycles, are common in small mammals and have important effects on predator populations and life histories. In this thesis, I identify long-term patterns and processes in two specialist predators, the arctic fox Vulpes lagopus and the rough-legged buzzard Buteo lagopus, in relation to their prey (lemmings and voles) and in the case of the arctic fox also to a dominant competitor, the red fox Vulpes vulpes. READ MORE

4. 2. The role of herbivores in mediating responses of tundra ecosystems to climate change

   Author : Elina Kaarlejärvi; Johan Olofsson; Anu Eskelinen; Jon Moen; Eric Post; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Climate change; warming; grazer; Rangifer; Lemmus lemmus; species distribution; biotic interactions; altitude; Environmental Science; miljövetenskap;

   Abstract : The Arctic areas are warming more rapidly than other parts of the world. Increasing temperatures are predicted to result in shrubification, higher productivity, declining species diversity and new species invasions to the tundra. READ MORE

5. 3. Phylogeography and mitochondrial DNA diversity in arctic lemmings

   Author : Vadim B. Fedorov; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Genetics; Genetik; Clinical genetics; Klinisk genetik; Genetics; genetik;

   Abstract : The aim of this thesis is to evaluate the effects of Quaternary environmental fluctuations on the present patterns of mitochondrial DNA variation in the wood lemming, Myopus schisticolor, and the two genera of Arctic lemmings: collared lemmings, Dicrostonyx, and true lemmings, Lemmus.The phylogeographic pattern and the limited mtDNA diversity in the Scandinavian populations of the wood lemming reflect recent colonization by a limited number of founders during the Holocene boreal forest expansion. READ MORE

6. 4. Animal movement on short and long time scales and the effect on genetic diversity in cold-adapted species

   Author : Vendela Kempe Lagerholm; Love Dalén; Anders Angerbjörn; Bensch Staffan; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Systematic Zoology; zoologisk systematik och evolutionsforskning;

   Abstract : The genetic diversity in modern species is strongly affected by contemporary gene flow between populations, which in turn is governed by individual dispersal capacities and barriers in the landscape. However, current patterns of variation have also been shaped by movement over longer time-scales, such as the successive shifts in species distributions that have occurred during past climate changes. READ MORE

7. 5. The zoo-geomorphological impact of fossorial rodents in sub-polar alpine environments

   Author : Bert Eriksson; Jan Boelhowers; John Östh; Hanna Ridefelt; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; zoo-geomorphology; fossorial rodents; sub-polar; alpine; geomorphic work; ecosystem engineers; Physical geography; Naturgeografi; Geography; Geografi;

   Abstract : The geomorphological impact of small fossorial mammals (adapted to digging and living underground), such as rodents can be significant, and both their direct and indirect effects may contribute to landscape formation. This thesis is based on empirical field studies of two burrowing rodent species in sub-polar environments, namely invasive House mice (Mus musculus) on sub-Antarctic Marion Island and Norwegian lemmings (Lemmus lemmus) in sub-Arctic Abisko. READ MORE