Search for dissertations about: "new species"

Showing result 16 - 20 of 1337 swedish dissertations containing the words new species.

2. 16. Biotic resistance in freshwater fish communities

   Author : Anna Henriksson; Göran Englund; David Wardle A.; Jun Yu; Sebastian Diehl; Donald Jackson; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; biotic resistance; freshwater fish; introductions; invasions; invasion success; invasibility; invasiveness; species richness; saturation; species identity; weighted species richness;

   Abstract : Invasions of non-native species cause problems in ecosystems worldwide, and despite the extensive effort that has been put into research about invasions, we still lack a good understanding for why some, but not other, communities resist these invasions. In this doctoral thesis I test hypotheses on biotic resistance using a large dataset of more than 1000 both failed and successful introductions of freshwater fish into Swedish lakes. READ MORE

4. 17. Effects of climate change on boreal wetland and riparian vegetation

   Author : Lotta Ström; Roland Jansson; Christer Nilsson; Sarah Gergel; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; biomass; flooding; hydrologic niche; invasibility; riparian zone; riparian plant species; river margin; climate scenario; seed sowing experiment; species composition; species richness; transplant experiment; Terrestrial ecology; Terrestrisk ekologi;

   Abstract : Models of climate change predict that temperature will increase during the 21th century and the largest warming will take place at high northern latitudes. In addition to warming, predictions for northern Europe include increased annual precipitation and a higher proportion of the precipitation during winter falling as rain instead of snow. READ MORE

5. 18. Delayed Cell Death after Traumatic Brain Injury : Role of Reactive Oxygen Species

   Author : Fredrik Clausen; Lars Hillered; Tiit Mathiesen; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neurosciences; Traumatic Brain Injury; Reactive oxygen species; Fluid percussion injury; Controlled cortical impact; weight drop injury; Extracellular-signal regulated kinase; apoptosis; free radical scavenging; morphology; functional outcome; Neurovetenskap; Neurology; Neurologi;

   Abstract : Traumatic brain injury (TBI) is a leading cause of death and disability TBI survivors often suffer from severe disturbances of cognition, memory and emotions. Improving the treatment is of great importance, but as of yet no specific neuroprotective treatment has been found. READ MORE

6. 19. Multi-trait Branching Models with Applications to Species Evolution

   Author : Daniah Tahir; Ingemar Kaj; Martin Lascoux; Asger Hobolth; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Markov models; branching processes; density dependence; discrete traits; species trees; diversification rates; diffusion approximation;

   Abstract : This thesis provides an analysis of the evolution of discrete traits and their effect on the birth and survival of species using the theory of supercritical, continuous time Markov branching processes. We present a branching modeling framework that incorporates multi-trait diversification processes associated with the emergence of new species, death of existing species, and transition of species carrying one type of a trait to another. READ MORE

7. 20. Species Responses to Environmental Fluctuations : impacts of food web interactions and noise color

   Author : Sara Gudmundson; Uno Wennergren; Anna Eklöf; Sebastian Diehl; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Species constantly experience changes in their environmental conditions owing to natural or human induces reasons. Understanding how species respond to these fluctuations are important for ecology, especially given the ongoing climate change. Empirical studies have shown that species respond differently to the same disturbance. READ MORE