Sökning: "Alternative stable state"
Visar resultat 1 - 5 av 57 avhandlingar innehållade orden Alternative stable state.
1. Upholding the coral loop : Resilience, alternative stable states and feedbacks in coral reefs
Sammanfattning : Coral reefs are suffering unprecedented declines in coral cover and species diversity. These changes are often associated with substantial shifts in community structure to new dominant organisms. Ultimately, these “phase shifts” can be persistent and very difficult to return from. LÄS MER
2. Alternative Stable States in Size-Structured Communities : Patterns, Processes, and Mechanisms
Sammanfattning : Alternative stable states have been, based on theoretical findings, predicted to be common in ecological systems. Empirical data from a number of laboratory and natural studies strongly suggest that alternative stable states also occur in real populations, communities and ecosystems. LÄS MER
3. Long-lasting ecological legacies of reindeer on tundra vegetation
Sammanfattning : Reindeer can have strong effects on the plant species composition and functioning of tundra ecosystems, and often promote a transition towards a graminoid-dominated vegetation type. As a result, they influence many ecological processes, such as nutrient dynamics, soil biotic composition and functioning, and carbon storage. LÄS MER
4. Submerged macrophytes in shallow eutrophic lakes - regulating factors and ecosystem effects
Sammanfattning : In this thesis I have studied factors that regulate submerged macrophyte abundance, morphology and distribution in shallow eutrophic lakes, and how submerged macrophytes may affect the ecosystem. Light attenuation through the water column (turbidity and water depth) is probably not the most important factor regulating the distribution of submerged vegetation in macrophyte dominated shallow eutrophic lakes, e. LÄS MER
5. Competing Under Pressure : State Anxiety, Sports Performance and Assessment
Sammanfattning : Elevated levels of anxiety are a common response to stressful competitive sports situations, are known to moderate athletic performance and are referred to as an unpleasant emotional state associated with perceptions of situational threat. The empirical studies in this dissertation considered primarily psychometric, methodological and conceptual issues of relevance for the study of anxiety and sports performance. LÄS MER
