Sökning: "Species introductions"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Species introductions.

1. 1. Biotic resistance in freshwater fish communities

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

   Sammanfattning : 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. LÄS MER

3. 2. Nesting and migration in the introduced Canada goose in Sweden

   Författare :Göran Sjöberg; Catherine M. Lessells; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Species introductions; DNA fingerprinting; natal dispersal; breeding dispersal; bird migration; wintering areas; clutch size; laying date; body reserves; nest defence; waterfowl; Canada goose; Anatidae; Branta canadensis;

   Sammanfattning : The aim of the thesis was to document patterns in breeding and migration in Swedish Canada geese Branta canadensis, to explain these against the genetic and historical background of the population, and to test predictions of hypotheses pertaining to parental investment.The Canada goose population in Sweden was founded by the introduction of a few individuals in the 1930's. LÄS MER

4. 3. Benthic use of phytoplankton blooms: uptake, burial and biodiversity effects in a species-poor system

   Författare :Agnes M. L. Karlson; Ragnar Elmgren; Carlo Heip; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biodiversity; ecosystem functioning; benthic-pelagic coupling; niche; resource partitioning; competition; eutrophication; cyanobacterial blooms; diatoms; invasive species; Baltic Sea; Marine ecology; Marin ekologi; Marine Ecology; marin ekologi;

   Sammanfattning : Animals living in marine sediments (the second largest habitat on earth) play a major role in global biogeochemical cycling. By feeding on organic matter from settled phytoplankton blooms they produce food for higher trophic levels and nutrients that can fuel primary production. LÄS MER

5. 4. Marine seaweed invasions : Impacts and biotic resistance in native ecosystems

   Författare :Josefin Sagerman; Sofia Wikström; Fransisco Arenas; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plant invasion; exotic species; generalist herbivores; plant-herbivore interactions; enemy-release hypothesis; ecosystem function; marin ekotoxikologi; Marine Ecotoxicology;

   Sammanfattning : Marine seaweeds constitute one of the most productive plant systems known on Earth and a rich fauna including juvenile fish and crustaceans is dependent on the habitats they form. Human influence on marine costal ecosystems has resulted in large scale changes to the abundance and distribution of species, where species introductions constitute an obvious part. LÄS MER

7. 5. Introduced and indigenous macroalgae : Ecological effects, functions and regulating factors in tropical seascapes

   Författare :Maria Eggertsen; Christina Halling; Charlotte Berkström; Johan Eklöf; Jennifer Smith; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; macroalgae; introduced species; coral-algae interactions; nursery habitats; herbivory; Eucheuma denticulatum; tropical seascape; Marine Ecology; marin ekologi;

   Sammanfattning : Tropical marine shallow-water areas are highly productive systems that promote important ecological functions and biodiversity. Stressors on these systems are intensifying due to increasing anthropogenic disturbances on multiple scales. LÄS MER