Sökning: "bestånd"

Visar resultat 21 - 25 av 32 avhandlingar innehållade ordet bestånd.

  1. 21. A System Perspective on Energy End-Use Measures in a District Heated Region : Renovation of Buildings and Hydronic Pavement Systems

    Författare :Stefan Blomqvist; Louise Ödlund; Patrik Rohdin; Jan Akander; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : A district heating and cooling (DHC) system can be a viable piece of the puzzle in the efforts of reducing the greenhouse gas (GHG) emissions. Especially if the DHC system include combined heat and power (CHP) plants which enable electricity production from renewable resources. LÄS MER

  3. 22. 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

  4. 23. Nutrient and Organic Matter Dynamics in Beech Forest Floors, in Relation to the Presence of Ground Flora

    Författare :Frida Andréasson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bioavailability; mineralisation; soil acidity; soil matrix solution; soil leachate; nitrate; ammonia; dissolved organic carbon; beech; Ground flora; forest floor; O horizon; A horizon; Plant ecology; Växtekologi;

    Sammanfattning : The objective of this thesis was to quantify differences between adjacent patches with and without ground flora of Deschampsia flexuosa L. Trin or Anemone nemorosa L. in two acid European beech (Fagus sylvatica L.) forest floors in south-west of Sweden. LÄS MER

  5. 24. The Late Holocene history of beech Fagus sylvatica and Norway spruce Picea abies at stand-scale in southern Sweden

    Författare :Leif Björkman; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; south Sweden; Late Holocene; succession; disturbance; forest history; forest continuity; population dynamics; immigration; palaeoecology; pollen analysis; Fagus sylvatica; Picea abies; Geologi; fysisk geografi; Palaeobotany; phylogeny; palynology; Paleobotanik; fylogeni; palynologi;

    Sammanfattning : High resolution pollen analysis was carried out on five peat profiles from small forest hollows at four sites in southern Sweden. The general aim was to investigate the establishment of Fagus sylvatica and Picea abies at stand-scale. LÄS MER

  7. 25. Metapopulation ecology of Osmoderma eremita - dispersal, habitat quality and habitat history

    Författare :Jonas Hedin; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; extinction debt; habitat history; habitat quality; pheromone; telemetry; capture-mark-recapture; metapopulation; dispersal; oak; Osmoderma eremita; beetle; Animal ecology; Djurekologi;

    Sammanfattning : This thesis starts with a review of different biodiversity assessment methods in forests and the rest deals with the metapopulation ecology of Osmoderma eremita, a threatened beetle living in hollow trees. I concentrate on the effect of dispersal, habitat quality and habitat history for the presence, population size and future survival of this species. LÄS MER