Sökning: "future populations"

Visar resultat 1 - 5 av 349 avhandlingar innehållade orden future populations.

  1. 1. Ecotoxicological studies on giant clams (Tridacnidae) : Environmental problems and future concerns

    Författare :Eva Blidberg; Michael Tedengren; David Klumpp; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; giant clam; larval; physiology; zooxanthellae; Biology; Biologi;

    Sammanfattning : Giant clams (Tridacnidae; Bivalvia) are described as important framework builders on coral reefs in the Indo-Pacific region. They are phototrophic as they are associated with primary producing zooxanthellae. Populations are low due to over-exploitation and most species are now endangered in many areas. LÄS MER

  2. 2. The dynamics in harvested populations

    Författare :Anders Wikström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fluctuations; temporal; state-space; Harvest; cod; vendace; elasticity; stage-structured; stochastic; growth-rate; Baltic Sea; Bothnian Bay;

    Sammanfattning : We are interested in the effect of harvesting on population fluctuations and for that purpose we develop and analyze an age-structured model where recruitment is a stochastic process and the adult segment of the population is harvested. When a constant annual harvest is taken the coefficient of variation of the adult population increases for most parameter values due to the age truncation effect, i. LÄS MER

  3. 3. Microsimulation and tourism forecasts

    Författare :Anders Lundgren; Umeå universitet; []
    Nyckelord :modelling; tourism; microsimulation; future populations; poisson regression; multinomial logit regression; interaction model;

    Sammanfattning : .... LÄS MER

  4. 4. The Niches of Bacterial Populations in Productive Waters : Examples from Coastal Waters and Four Eutrophic Lakes

    Författare :Alexander Eiler; Stefan Bertilsson; Lars J. Tranvik; Janet Jansson; Katherine McMahon; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; diversity; 16S rRNA; phytoplankton; bloom; pathogen; carbon cycle; Ekologi;

    Sammanfattning : Recent research in microbial ecology has focused on how aquatic bacterial communities are assembled. Only a few of these studies follow a “Gleasonian” approach where the roles of single bacterial populations are in focus. LÄS MER

  5. 5. Virus Dynamics in Naturally Varroa-Resistant Honeybee Populations

    Författare :Srinivas Thaduri; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The ectoparasitic mite, Varroa destructor, together with its associated viruses is the most significant threat to honeybee (Apis mellifera) health world-wide. Since the introduction of varroa to the new host species, the European honey bee (Apis mellifera), it has been responsible for the near complete eradication of wild and feral honeybee populations in Europe and North America. LÄS MER