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Visar resultat 1 - 5 av 13 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Ecology across Boundaries : Food web coupling among and within ecosystems

   Författare :Pia Bartels; Peter Eklöv; Lars J. Tranvik; Daniel E. Schindler; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cross-ecosystem; food web; habitat coupling; terrestrial-aquatic linkages; subsidy; allochthonous; lake ecosystem; population divergence; trait variation; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; Freshwater ecology; Limnisk ekologi; Biology; Biologi; Biologi med inriktning mot limnologi; Biology with specialization in Limnology;

   Sammanfattning : Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. LÄS MER

3. 2. Population divergence at small spatial scales : – theoretical and empirical investigations in perch

   Författare :Sara Bergek; Mats Björklund; Teija Aho; Sarah Goodacre; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Perca fluviatilis L.; Perch; Small scale genetic differentiation; Morphometrics; Isolation by distance; Dispersal; Gene flow; Microsatellites; Spatiotemporal stability; Barriers; Biology; Biologi; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

   Sammanfattning : Genetically structured populations arise when gene flow between groups of individuals is hindered by geographical, behavioural or temporal barriers. The identification of such groups is important for understanding evolution and has large implications for conservation concern. LÄS MER

4. 3. Survival patterns and density-dependent processes in breeding mallards Anas platyrhynchos

   Författare :Gunnar Gunnarsson; Kjell Sjöberg; Johan Elmberg; Per Lundberg; Robert Clark; Högskolan Kristianstad; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; broods; dabbling ducks; density dependence; ducklings; experiments; models; mortality; nest predation; regulation; survival; Terrestrial ecology; Terrestrisk ekologi;

   Sammanfattning : Measuring and assessing vital rates such as births and deaths are prerequisites for understanding population dynamics. Vital rates may be affected by the density of individuals, even though the importance of density dependence on population dynamics has been debated for a long time. LÄS MER

5. 4. Treeline dynamics in short and long term perspectives : observational and historical evidence from the southern Swedish Scandes

   Författare :Lisa Öberg; Bengt-Gunnar Jonsson; Leif Kullman; Ulf Segerström; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; climate change; monitoring; treeline advance; clones; megafossils; immigration; Holocene; cryptic refugia; Swedish Scandes; Terrestrial ecology; Terrestrisk ekologi;

   Sammanfattning : Against the background of past, recent and future climate change, the present thesis addresses elevational shifts of alpine treelines in the Swedish Scandes. By definition, treeline refers to the elevation (m a.s.l. LÄS MER

7. 5. Genetic variation and gene flow in riparian populations of Filipendula ulmaria

   Författare :Åsa Bång; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Barriers; fragmentation; Filipendula ulmaria; Gene flow; genetic variation; hydrochory; pollen dispersal; riparian habitat; spatial genetic structure; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi;

   Sammanfattning : .... LÄS MER