Sökning: "Ecological factors"

Visar resultat 1 - 5 av 303 avhandlingar innehållade orden Ecological factors.

  1. 1. Ischemic heart disease in Kiruna : risk factors and sequelae

    Författare :Torbjörn Messner; Kurt Svärdsudd; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Ischemic heart disease; risk factors; alcohol; acetylsalicylic acid; lipids; fatty acids; diet; psychosocial risk factors; migration; smoking; mortality; diabetes mellitus; family history; heart failure;

    Sammanfattning : Kiruna, a Swedish community situated 300 km north of the Arctic Circle, has a very high mortality in ischemic heart disease (IHD). Acase-control study was undertaken to find out if the risk factors for IHD or their impact differed from those in other populations. LÄS MER

  3. 2. Making complex commons work : identifying critical social-ecological factors and mechanisms for sustainable ecosystem management

    Författare :Caroline Schill; Therese Lindahl; Björn Vollan; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Agent-based modelling; Behavioural experiments; Collective action; Common-pool resources; Cooperation; Ecological complexity; Knowledge sharing; Regime shifts; Social-ecological systems; Sustainable management; Thresholds; Uncertainty; Sustainability Science; vetenskap om hållbar utveckling;

    Sammanfattning : Collective action holds the key to many sustainability challenges, from local to global scales. Whether it is to manage community-based fisheries or take action against climate change or biodiversity loss – the question on how to overcome the conflict between individual and collective interests (i.e. LÄS MER

  4. 3. Human Behaviour in Social-Ecological Systems : Insights from economic experiments and agent-based modelling

    Författare :Caroline Schill; Therese Lindahl; Anne-Sophie Crépin; Johan Colding; Carl Folke; Juan Camilo Cárdenas; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Human behaviour; Common-pool resources; Ecological complexity; Collective action; Sustainable resource use; Regime shifts; Thresholds; Uncertainty; Communication; Knowledge-sharing; Economic experiments; Laboratory and field experiments; Agent-based modelling; Complex adaptive systems; Social-ecological systems; Sustainability Science; vetenskap om hållbar utveckling;

    Sammanfattning : Progress towards sustainability requires changes in our individual and collective behaviour. Yet, our fundamental understanding of behaviour in relation to environmental change remains severely limited. LÄS MER

  5. 4. Macroalgae in tropical seascapes : regulating factors and functions in the coastal ecosystem

    Författare :Gustaf Lilliesköld Sjöö; Max Troell; Nils Kautsky; Lena Kautsky; Alina Szmant; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Macroalgae; Coral reefs; Nutrients; Herbivory; Ecological functions; East Africa; Regulating factors; Anthropogenic influence; Seaweed farming; Bioindicator; marin ekotoxikologi; Marine Ecotoxicology;

    Sammanfattning : Although macroalgae usually are inconspicuous on pristine coral reefs, they often thrive on reefs that are subjected to various types of anthropogenic disturbance. This thesis consists of five papers and investigates how biomass and composition of macroalgal communities on coral reefs are affected by regulating factors, such as nutrient availability, herbivory, substrate availability and hydrodynamic forces. LÄS MER

  7. 5. Bird orientation: external cues and ecological factors

    Författare :Johan Bäckman; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tracking radar; Emlen funnel.; Animal ecology; Djurekologi; oscillatory orientation; roosting flight; scatter; concentration; heading; cue calibration; light dependent; magnetoreception; subcutaneous fat stores; body condition; energetics; geomagnetic field; visual cues; orientation; birds; migration;

    Sammanfattning : Birds are generally capable of accurate orientation. In this thesis I present studies about the external cues and the ecological factors that influences bird orientation. A multitude of environmental cues are used to select and maintain a proper direction. LÄS MER