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Visar resultat 1 - 5 av 48 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Effects of drought on boreal forest understory species

    Författare :Irena A. Koelemeijer; Kristoffer Hylander; Johan Asplund; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biodiversity conservation; boreal forests; bryophytes; canopy cover; climate change; drought; extreme climatic events; forest management; forest understory; fungi; lichens; plants; rainout shelter; soil communities; soil moisture; transplant experiment; Ecology and Evolution; ekologi och evolution;

    Sammanfattning : Extreme climatic events, such as droughts, can have large effects on biodiversity. Drought effects in forest understories are variable over small spatial scales and can be exacerbated, or buffered, by the local vegetation structure, distance to forest edges, hydrology, and soil characteristics. LÄS MER

  3. 2. Pollinators, Enemies, Drought, and the Evolution of Reproductive Traits in Primula farinosa

    Författare :Per Toräng; Jon Ågren; Johan Ehrlén; Rebecca Irwin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Alternative reproductive strategies; climate change; facilitation; floral display; flowering phenology; frequency-dependent selection; genetic diversity; life-history strategies; local adaptation; pollination; predation; Primula farinosa; reproductive effort; soil disturbance; stochastic growth rate; Ekologi;

    Sammanfattning : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits and population differentiation in the insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically, I (1) determined whether the effects of floral display and interactions with pollinators and seed predators, and plant reproductive success were frequency-dependent and affected by surrounding vegetation context, (2) examined the consequences of intermittent drought years on population dynamics using numerical simulations based on demographic data collected over seven years, (3) analyzed among-population differentiation in flowering phenology and reproductive allocation, and its relationship to soil-depth at the site of origin. LÄS MER

  4. 3. Modeling the Potential for Carbon Removal in Agriculture: Integrating Farmer Perspectives

    Författare :Andreas Rehn; Chalmers tekniska högskola; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Crop Rotation; Climate Change Mitigation; Carbon Dioxide Removal CDR Agricultural Practices; Stakeholder participation; Perennial Ley Crops; Biochar; Soil Organic Carbon SOC ; Landscape Modeling;

    Sammanfattning : The overarching aim of this thesis is to provide insights into the dynamic processes governing SOC stocks and to identify viable paths for agricultural systems to contribute to climate change mitigation. By integrating current scientific knowledge of carbon sequestration in agriculture with feasible agricultural applications, this work proposes local realistic strategies for enhancing soil organic carbon (SOC) and presents a quantitative assessment of their potential for CO2 removal. LÄS MER

  5. 4. Carbon stock and fluxes in Nyungwe forest and Ruhande Arboretum in Rwanda

    Författare :Donat Nsabimana; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon stock; Litterfall production; Soil CO2 efflux; or soil respiration; Soil temperature; Soil water content; Spatial variation; Seasonal and diurnal variations;

    Sammanfattning : Conservation and sequestration of carbon in forest ecosystems are potential strategies to reduce or stabilize the atmospheric greenhouse gas concentrations and mitigate climate change. Estimating the... LÄS MER

  7. 5. Microbial Communities in Boreal Peatlands : Responses to Climate Change and Atmospheric Nitrogen and Sulfur Depositions

    Författare :Magalí Martí Genero; Bo Svensson; Åsa Danielsson; Torben Christensen; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Microbial communities; methanogens; plant communities; peatland; temperature; nitrogen; long-term; field experiment; high-throughput sequencing; Microbiella samhällen; metanogener; växtsamhällen; myrar; torv; temperatur; kväve; långtid; fältexperiment; high-throughput-sekvensering;

    Sammanfattning : Myrmarker har en stor roll i regleringen av den globala kolbalansen och koncentrationerna av koldioxid och metan i atmosfären, vilket gör dem till speciellt viktiga ekosystem ur ett klimatförandringsperspektiv. Förändringar av myrmarker genom naturlig utveckling eller antropogen påverkan kan därför få långtgående störningar av myrars klimatreglerande funktion. LÄS MER