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Visar resultat 1 - 5 av 114 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Phytophthora and Oak Decline - Impact on Seedlings and Mature Trees in Forest Soils

    Författare :Ulrika Jönsson Belyazid; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; microbial competition; carbon allocation; nutrients; water availability; soil chemistry; mature oaks; seedlings; acid soils; Phytophthora quercina; Quercus robur;

    Sammanfattning : This thesis investigated the occurrence of soilborne species of the plant pathogenic genus Phytophthora in southern Swedish oak forests and their possible involvement in southern Swedish oak decline. The emphasis was on the impact of P. quercina on Quercus robur in acid forest soils. LÄS MER

  3. 2. Volatiles of Conifer Seedlings : Compositions and Resistance Markers

    Författare :Astrid Kännaste; Anna-Karin Borg-Karlson; Anders Backlund; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conifers; Norway spruce; Scots pine; Nalepella; Oligonychus ununguis; green leaf volatiles; terpenes; aromatics; benzenoids; SPME; induced defense reaction; Organic chemistry; Organisk kemi;

    Sammanfattning : Pine weevils cause major damage to newly planted conifer seedlings in reforestation areas. However, recent findings indicate that small (“mini”) seedlings, planted at the age of 7-10 weeks, are gnawed less by pine weevils than the larger, conventionally planted seedlings. LÄS MER

  4. 3. Year-round production of forest seedlings under LED lamps : Biological and energetic implications of indoor cultivation

    Författare :Marco Hernandez Velasco; Uwe Zimmermann; Anders Mattsson; Frank Fiedler; Johanna Riikonen; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Picea abies; Pinus sylvestris; year-round cultivation; forest seedlings; LED lamps; light quality; light quantity; daily light integral; adaptive lighting control; greenhouse integrated photovoltaics; agrivoltaics; seedling growth performance; short-day treatments; cold hardiness; light shock stress; Engineering Science; Teknisk fysik;

    Sammanfattning : Year-round cultivation of forest seedlings under light emitting diodes (LED) is a technology receiving increased attention from nurseries in the boreal forest regions. In these areas, the climate is characterized by strong seasonal fluctuations, resulting in short vegetation periods with narrow time windows for seedling transplanting and outdoor growth. LÄS MER

  5. 4. Mosses as mediators of climate change : implications for tree seedling establishment in the tundra

    Författare :Signe Lett; Ellen Dorrepaal; David Wardle; Marie-Charlotte Nilsson; Vigdis Vandvik; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; arctic; alpine; B. pubescens; bryophytes; competition; facilitation; mosses; P. sylvestris; precipitation changes; seedlings; traits; tree line; warming;

    Sammanfattning : Alpine and arctic tree line expansion depends on the establishment of tree seedlings above the current tree line, which is expected to occur with climate warming. However, tree lines often fail to respond to higher temperatures. Other environmental factors are therefore likely important for tree seedling establishment. LÄS MER

  7. 5. Exploiting plant defenses to protect conifer seedlings against pine weevils

    Författare :Yayuan Chen; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Sweden is one of the top five countries having large planted forest areas, and here the forests are maintained by clear-cut regime, which also promotes the pine weevil (Hylobius abietis), a major threat to Swedish planted coniferous regeneration. Given interest in developing sustainable forest management practices, efficient non-insecticide alternatives are highly demanded to tackle the pine weevil problem. LÄS MER