Sökning: "species trait"

Visar resultat 1 - 5 av 145 avhandlingar innehållade orden species trait.

  1. 1. Multi-trait Branching Models with Applications to Species Evolution

    Författare :Daniah Tahir; Ingemar Kaj; Martin Lascoux; Asger Hobolth; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Markov models; branching processes; density dependence; discrete traits; species trees; diversification rates; diffusion approximation;

    Sammanfattning : This thesis provides an analysis of the evolution of discrete traits and their effect on the birth and survival of species using the theory of supercritical, continuous time Markov branching processes. We present a branching modeling framework that incorporates multi-trait diversification processes associated with the emergence of new species, death of existing species, and transition of species carrying one type of a trait to another. LÄS MER

  3. 2. Species interactions govern evolutionary and ecological effects of population harvesting

    Författare :Anna Gårdmark; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; population harvesting; species interactions; ecological community; Ekologi; Ecology; competition; predation; fisheries; spatial dynamics; maturation; population dynamics; life-history evolution; adaptation;

    Sammanfattning : Harvesting changes population abundance and can affect adaptation of several life-history traits. Harvesting can also have indirect effects ? effects on non-target species and secondary effects on target species ? because interactions between species in a community determine the relevant ecological and evolutionary feedback environment. LÄS MER

  4. 3. Effects of community- and government-managed marine protected areas on tropical seagrass and coral communities

    Författare :Angelica Chirico; Johan Eklöf; Nils Kautsky; Even Moland; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coastal ecosystems; conservation; marine spatial planning; locally managed; fisheries closure; benthic communities; fish; foundation species; macroalgae; secondary succession; life-history; trait variability; plasticity; tourism; human disturbance; fishing; experimental research; Western Indian Ocean; causal modelling; structural equation model; permanova; multivariate data; marin ekotoxikologi; Marine Ecotoxicology;

    Sammanfattning : Tropical seagrass beds and coral reefs are among the most productive and diverse ecosystems on Earth and provide ecosystem services, such as fish production and coastal protection, and support livelihoods of millions of people. At the same time, these ecosystems are threatened globally by anthropogenic disturbances, such as overfishing, pollution and global warming. LÄS MER

  5. 4. Natural enemies: Functional aspects of local management in agricultural landscapes

    Författare :Helena Hanson; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Agricultural intensification; sustainable agriculture; land use; management intensity; landscape scale; ecosystem services; biological control; species trait; pesticides; predatory arthropods; parasitoids; pollen beetles;

    Sammanfattning : Agricultural intensification has raised the global food production but also caused major concerns about environmental and health effects, including contamination by pesticides. Pesticide applications may induce toxicity not only on the target pest species but especially on non-target species. LÄS MER

  7. 5. Evolution of Plants : a mathematical perspective

    Författare :Magnus Lindh; Åke Brännström; Jacob Johansson; Mats G Larson; Lennart Persson; Claus Rüffler; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Evolution; plants; mathematics; optimization; optimal control; adaptive dynamics; flowering; seasons; tree crown; drought; taproot; trade-off; strategy; trait; ESS; NPP; LAI; Red Queen; Mathematics; matematik;

    Sammanfattning : The Earth harbors around 300 000 plant species. The rich and complex environment provided by plants is considered a key factor for the extraordinary diversity of the terrestrial fauna by, for example, providing food and shelter. LÄS MER