Sökning: "invasions"

Visar resultat 1 - 5 av 26 avhandlingar innehållade ordet invasions.

1. 1. Marine Seaweed Invasions : the Ecology of Introduced Fucus evanescens

   Författare :Sofia A. Wikström; Lena Kautsky; Ove Eriksson; Paul Lavery; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; biological invasions; marine; seaweed; algae; herbivory; enemy release hypothesis; phlorotannins; anti-fouling; Fucus evanescens; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : Biological invasions are an important issue of global change and an increased understanding of invasion processes is of crucial importance for both conservation managers and international trade. In this thesis, I have studied the invasion of the brown seaweed Fucus evanescens, to investigate the fate and effect of a perennial, habitat-forming seaweed introduced to a coastal ecosystem. LÄS MER

3. 2. Marine seaweed invasions : Impacts and biotic resistance in native ecosystems

   Författare :Josefin Sagerman; Sofia Wikström; Fransisco Arenas; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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

4. 3. Seaweed Invasions and Novel Chemical Defences

   Författare :Swantje Enge; Göteborgs universitet; Göteborgs universitet; Gothenburg University; Göteborgs universitet; Gothenburg University; Göteborgs universitet; Gothenburg University; []
   Nyckelord :Biological invasions; enemy release; increased competitive ability; novel weapon; chemical defence; plant-herbivore interactions; competition; seaweeds; Bonnemaisonia hamifera;

   Sammanfattning : Biological invasions pose a risk to the biodiversity and the functioning of ecosystems in invaded areas. The reasons why some introduced species become dominant and widespread in their new environments is still largely an unsettled question. LÄS MER

5. 4. Biotic resistance in freshwater fish communities

   Författare :Anna Henriksson; Göran Englund; David Wardle A.; Jun Yu; Sebastian Diehl; Donald Jackson; Umeå universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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

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

   Författare :Helena Berglund; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; threats; distribution range; isolation; endemism; invasions; invaders; vulnerability; non indigenous species; rarity; threatened species;

   Sammanfattning : 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). LÄS MER