Sökning: "Kari Lehtilä"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Kari Lehtilä.

1. 1. Population Differentiation in Solidago virgaurea along Altitudinal Gradients

   Författare :Anna Bergsten; Jon Ågren; Staffan Karlsson; Kari Lehtilä; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; population differentiation; altitudinal gradient; plant nutrient status; resorption efficiency; resorption proficiency; flowering phenology; countergradient variation; reproductive effort; flower production; cost of reproduction; Biology; Biologi; Other biology; Övrig biologi; Ecological Botany; Ekologisk botanik;

   Sammanfattning : Altitudinal gradients offer attractive opportunities for studies of population differentiation in response to environmental heterogeneity. In this thesis, I examined population differentiation along altitudinal gradients by combining common-garden experiments with field studies and experiments in alpine, subalpine and boreal populations of the perennial herb Solidago virgaurea. LÄS MER

3. 2. Ecology and evolution of tolerance in two cruciferous species

   Författare :Elin Boalt; Kari Lehtilä; Johan Ehrlén; Julia Koricheva; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; herbivory; tolerance; methodology; Raphanus raphanistrum; Cardamine pratensis; folivory; apex removal; plant competition; ploidy levels; herbivore pressure; Other biology; Övrig biologi; växtekologi; Plant Ecology;

   Sammanfattning : Tolerance to herbivory is the ability of plants to maintain fitness in spite of damage. The goal of this thesis is to investigate the genetic variation and expression of tolerance within species, determine whether and in what conditions tolerance has negative side-effects, and how tolerance is affected by different ecological factors. LÄS MER

4. 3. Pollination processes - maternal and offspring performance

   Författare :Kristina Holmén Bränn; Kari Lehtilä; Pia Mutikainen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pollination; Sinapis arvensis; Brassica napus; Raphanus raphanistrum; Succisa pratensis; Evolution of flower size; Maternal plant responses; Resource allocation; Reproductive success; Terrestrial ecology; Terrestisk ekologi; Plant Ecology; växtekologi;

   Sammanfattning : Pollination is one of the most important factors determining the reproductive success of plants. This thesis examines processes associated to varying pollination, with focus on plant responses. The first aim was to examine the possibility and constraints for short-term evolution of flower size in Raphanus raphanistrum. LÄS MER

5. 4. Ecology and Evolution of Resistance to Herbivory : Trichome Production in Arabidopsis lyrata

   Författare :Geir Løe; Jon Ågren; Kari Lehtilä; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Plant-animal interactions; herbivory; trichomes; plant resistance; plant defense; divergent selection; local adaptation; GLABROUS1; evolution; matrix population models; LTRE; Biologi; Biology; Biologi;

   Sammanfattning : In this thesis, I examine variation in occurrence and performance of glabrous and trichome-producing plants of the perennial herb Arabidopsis lyrata. I combine field studies and genetic analysis to (1) examine the function of trichomes as a resistance character in natural populations, (2) compare the magnitude of population differentiation in trichome-production and at putatively neutral marker loci, (3) examine the molecular genetic basis of trichome-production, and (4) quantify the effects of herbivore removal on population growth and relative performance of glabrous and trichome-producing plants. LÄS MER

7. 5. Livelihood Implications of Large-Scale Land Concessions in Mozambique : A case of family farmers’ endurance

   Författare :Juliana Porsani; Kari Lehtilä; Rickard Lalander; Lowe Börjeson; Randi Kaarhus; Södertörns högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Large-scale land acquisitions; land concessions; land grabs; livelihoods; family farmers; peasants; gender; community consultations; popular deliberation; cultural ecosystem services; Mozambique; Lower Limpopo Valley; Environmental Studies; Miljövetenskapliga studier;

   Sammanfattning : This thesis examines the process and the implications of large-scale land acquisitions (LSLAs) for local livelihoods, especially the livelihoods of those who make a living from farming. These individuals were historically known as peasants and are now more commonly referred to as smallholders, small-scale farmers or family farmers. LÄS MER