Search for dissertations about: "Species distribution"

Showing result 1 - 5 of 603 swedish dissertations containing the words Species distribution.

  1. 1. Phylogeny, taxonomy and species delimitation of water mites and velvet mites

    University dissertation from Stockholm : Department of Zoology, Stockholm University

    Author : Jeanette Stålstedt; Johannes Bergsten; Fredrik Ronquist; Joanna Mąkol; Ashley Dowling; [2017]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Acariformes; Parasitengona; Hydrachnidia; Trombidia; water mites; velvet mites; taxonomy; cryptic species; species delimitation; DNA; GMYC; experimental rearing; new synonyms; distribution; phylogeny; revised classification; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Abstract : This study is part of the Swedish Taxonomy Initiative (STI) - one of the most ambitious all taxa biodiversity inventories in the world. One of the pillars in STI is to support taxonomic research on the most neglected taxonomic groups with the aim to lift the level of knowledge of biodiversity in the country. READ MORE

  2. 2. The threat from non indigenous species - ecosystem vulnerability, global distribution and co-occurrence with other major threats

    University dissertation from Stockholm : Department of Zoology, Stockholm University

    Author : Helena Berglund; [2009]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; threats; distribution range; isolation; endemism; invasions; invaders; vulnerability; non indigenous species; rarity; threatened species;

    Abstract : We live in a globalised world where people and goods travel large distances. Various species are brought along on these journeys, intentionally or as hitchhikers. Some of these species establish populations in regions to which they could not have spread without human assistance, and where they are considered to be non indigenous species (NIS). READ MORE

  3. 3. The role of microclimate for the performance and distribution of forest plants

    University dissertation from Stockholm : Department of Zoology, Stockholm University

    Author : C. Johan Dahlberg; Kristoffer Hylander; Johan Ehrlén; Jason D. Fridley; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; performance; microclimate; spatial scales; continental; landscape; distribution patterns; distribution limits; phenology; vegetative development; reproductive development; vital rates; population growth rate; vascular plants; bryophytes; distribution modelling; Plant Ecology; växtekologi;

    Abstract : Microclimatic gradients may have large influence on individual vital rates and population growth rates of species, and limit their distributions. Therefore, I focused on the influence of microclimate on individual performance and distribution of species. READ MORE

  4. 4. Modelling spatial and temporal species distribution in the Baltic Sea phytobenthic zone

    University dissertation from Stockholm : Department of Systems Ecology, Stockholm University

    Author : Antonia Nyström Sandman; Hans Kautsky; Martin Isaeus; Georg Martin; [2011]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; species distribution modelling; niche; gradient; prediction; environmental factors; phytobenthos; scale; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Marine ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Marin ekologi; marin ekologi; Marine Ecology;

    Abstract : Statistical modelling is often used to relate the presence or abundance of species to environmental predictors, thereby providing a basis for predictive mapping of species or biodiversity. The variables included must thus be relevant and reflect actual changes in the environment. READ MORE

  5. 5. Plants go with the flow predicting spatial distribution of plant species in the boreal forest

    University dissertation from Umeå : Ekologi och geovetenskap

    Author : Ursula Zinko; Christer Nilsson; Håkan Rydin; [2004]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; boreal forest; vascular plant; species richness; wetness index; soil pH; bryophyte; lichen; substrate; stand age; plot size; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Abstract : The main objectives of this thesis are to study if a topographic wetness index (TWI) could be used as a tool for predicting the spatial distribution of vascular plant species richness in the boreal forest as well as to study congruence in species richness between vascular plants, liverworts, mosses and lichens. A wetness index ln(a/tanβ) based on topography was used to assign a specific TWI-value to every 20 x 20m grid in two 25 km2 boreal forest landscapes (differing in average soil pH) in northern Sweden. READ MORE