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Showing result 1 - 5 of 191 swedish dissertations matching the above criteria.

  2. 1. Modelling animal populations

    Author : Åke Brännström; Umeå universitet; []
    Keywords : population model; stochastic population model; population dynamics; discrete time model; Beverton-Holt model; Skellam model; Hassell model; Ricker model; first principles; coupled map lattice; CML; area integral; square function; Mathematics; matematik;

    Abstract : This thesis consists of four papers, three papers about modelling animal populations and one paper about an area integral estimate for solutions of partial differential equations on non-smooth domains. The papers are: I. Å. Brännström, Single species population models from first principles. READ MORE

  4. 2. Interaction strength and keystone species in model food webs

    Author : Maria Christianou; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; interaction strength; keystone species; keystone links; permanence; resilience; local stability; Lotka-Volterra models; species loss;

    Abstract : Ecological communities are often exposed to different kind of disturbances of varied magnitude. The response to disturbances can be affected by, among other factors, the strength of interactions between species within the community. READ MORE

  5. 3. Potential impact of climate change on European agriculture: a case study of potato and Colorado potato beetle

    Author : Bakhtiyor Pulatov; Institutionen för naturgeografi och ekosystemvetenskap; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Colorado potato beetle; climate change; day length; degree day model; frost damage; distribution; temperature; potato; regional climate model; synchrony;

    Abstract : European agriculture is facing the challenge of managing the impact of climate change on food security. Agriculture in a northern temperate climate is likely to benefit from higher temperature and longer growing season while, in the south, crop productivity is likely to decline. READ MORE

  6. 4. A Detailed Kinetic Model for Calculation of the Soot Particle Size Distribution Function

    Author : Fikret Saric; Förbränningsfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Gaser; fluiddynamik; plasma; Motors and propulsion systems; Motorer; framdrivningssystem; plasmas; fluid dynamics; Gases; Fysik; Physics; Computational Fluid Dynamics; Sectional Method; Method of Moments; Diesel Like Engine Condition; Distribution Function; Detailed Kinetic Soot Model; Soot Particle Size;

    Abstract : The soot particle size distribution was studied via numerical simulation under diesel like engine conditions using a detailed kinetic soot model. Two different mathematical methods of the soot model description have been used in this work. In the first part of the work, the method of moments is presented. READ MORE

  7. 5. Distribution Patterns and Metapopulation Dynamics of Epiphytic Mosses and Lichens

    Author : Tord Snäll; Håkan Rydin; Johan Ehrlén; Christine Ray; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; plant; metapopulation; model; parameterization; connectivity; dispersal; colonization; extinction; epiphytic; bryophyte; lichen; boreal; fragmentation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : This thesis examines the relative importance of local conditions, dispersal and dynamics of the trees on epiphyte distribution patterns and colonization-extinction dynamics. Study species are the mosses Orthotrichum speciosum and O. obtusifolium, and the red-listed Neckera pennata. READ MORE