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Visar resultat 1 - 5 av 63 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Grassland restoration : Connectivity, plant community change and cows

    Författare :Rozália E. Kapás; Sara Cousins; Adam Kimberley; Lars A. Brudvig; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; biodiversity; colonization; connectivity; dispersal; distance to species pool; diversity; grassland restoration; grassland specialist species; grazing livestock; habitat availability; plant community composition; restoration; semi-natural grassland; species richness; naturgeografi; Physical Geography;

    Sammanfattning : The ecological significance of semi-natural grasslands is high because these habitats provide a home for a diverse flora and fauna and support a range of associated ecosystem services. Due to large-scale land-use changes the extent of grassland habitat has declined. LÄS MER

  3. 2. Seed mobility and connectivity in changing rural landscapes

    Författare :Alistair G. Auffret; Sara Cousins; Robin Pakeman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Biodiversity; Conservation; Functional connectivity; Historical ecology; Human-mediated dispersal; Invasive species; Landscape Ecology; Long-distance dispersal; Restoration; Seed bank; Seed dispersal; Seed rain; Structural connectivity; Physical Geography; naturgeografi;

    Sammanfattning : The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world's most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that many plant species are left only on small fragments of former habitat. LÄS MER

  4. 3. The use of highway crossings to maintain landscape connectivity for moose and roe deer

    Författare :Mattias Olsson; Per Widén; Anthony Clevenger; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; wildlife crossings; Barrier effect; habitat selection; ecoduct; moose; roe deer; connectivity; conservation; overpass; underpass; highway; exclusion fencing; Biology; Biologi; Biology; Biologi;

    Sammanfattning : Increasingly wildlife managers and land managers are challenged to maintain the viability and connectivity among large mammal populations. Thus, it is important that effective highway crossings are identified and optimized with respect to construction cost, facilitation of ungulate movements, and ability to reduce wildlife-vehicle collisions. LÄS MER

  5. 4. Sensitivity, Variation, and Application of Least-Cost Path Models in Landscape Connectivity Analysis and Corridor Planning

    Författare :Rachel Mundeli Murekatete; Takeshi Shirabe; Gyözö Gidofalvi; Jean Pierre Bizimana; Gerhard Navratil; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Landscape connectivity; Conservation corridor; Stepping stones; Effective distance; Geographic Information Systems; Raster data; Land evaluation; Suitability analysis; Cost surface; Suitability surface; Ordinal scale; Least-cost path; Spatial resolution; Landskapsanslutning; Bevarandekorridor; Stegbräda; Effektivt avstånd; Geografiska informationssystem; Rasterdata; Markutvärdering; Lämplighetsanalys; Kostnadsyta; Lämplighetsyta; Ordinal skala; Lägsta kostnadsväg; Rumslig upplösning; Geoinformatik; Geoinformatics;

    Sammanfattning : In recent decades, Rwanda has been affected by the loss and fragmentation of natural habitats for native species of animals and plants. As a consequence, landscape connectivity—i.e. LÄS MER

  7. 5. Dispersal of bryophytes across landscapes

    Författare :Niklas Lönnell; Kristoffer Hylander; Bengt Gunnar Jonsson; Sebastian Sundberg; Johan Ehrlén; Risto Virtanen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; anemochory; bryophytes; colonization; connectivity; diaspores; dispersal kernel; establishment; spore dispersal; long-distance dispersal; mechanistic model; mosses; realized dispersal; spore release; Lagrangian stochastic model; wind dispersal; Plant Ecology; växtekologi;

    Sammanfattning : Dispersal, especially long-distance dispersal, is an important component in many disciplines within biology. Many species are passively dispersed by wind, not least spore-dispersed organisms.In this thesis I investigated the dispersal capacity of bryophytes by studying the colonization patterns from local scales (100 m) to landscape scales (20 km). LÄS MER