Search for dissertations about: "latitudinal gradient"

Showing result 1 - 5 of 29 swedish dissertations containing the words latitudinal gradient.

  1. 1. Ecological and Evolutionary Consequences of Herbivory in the Perennial Herb Lythrum salicaria

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Lina Lehndal; Uppsala universitet.; [2015]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Disturbance gradient; Female reproductive success; Galerucella calmariensis; Galerucella pusilla; Herbivore removal; Latitudinal gradient; Local adaptation; Nanophyes marmoratus; Plant-herbivore interactions; Plant size; Resistance to herbivory; Tolerance to damage; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : In this thesis, I combined field, common-garden and greenhouse experiments to examine the ecological and evolutionary consequences of plant-herbivore interactions in the perennial herb Lythrum salicaria. More specifically I examined (1) whether resistance and tolerance to damage from herbivores vary with latitude and are positively related to the intensity of herbivory in natural populations, (2) whether effects of herbivory on plant fitness vary with latitude, (3) whether populations are locally adapted and whether herbivory influences the relative fitness of populations, and (4) whether the intensity and effects of insect herbivory on reproductive output vary locally along a disturbance gradient and are associated with differences in plant resistance. READ MORE

  2. 2. Thermal adaptation along a latitudinal gradient in damselflies

    University dissertation from Umeå : Umeå universitet

    Author : Viktor Nilsson-Örtman; Umeå universitet.; [2012]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Growth rate; metabolic theory of ecology; universal temperature dependence; environmental gradients; thermal performance; thermal sensitivity; environmental variability; optimality theory; life history; acclimation; size structure; competition; cannibalism; intraguild predation;

    Abstract : Understanding how temperature affects biological systems is a central question in ecology and evolutionary biology. Anthropogenic climate change adds urgency to this topic, as the demise or success of species under climate change is expected to depend on how temperature affects important aspects of organismal performance, such as growth, development, survival and reproduction. READ MORE

  3. 3. Population differentiation in Lythrum salicaria along a latitudinal gradient

    University dissertation from Umeå : Umeå universitet

    Author : Katarina Olsson; Umeå universitet.; [2004]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; additive genetic variance; clinal variation; evolutionary constraints; G matrix; genetic correlation; natural selection; pollen limitation; population differentiation; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Abstract : In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. READ MORE

  4. 4. Immunogenetic variation along the latitudinal gradient in Scandinavian anuran species Evolutionary processes, demography and infection

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Maria Cortazar-Chinarro; Uppsala universitet.; [2019]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biologi; Biology; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

    Abstract : The evolutionary and demographic processes affecting how genetic variation is partitioned and distributed over large geographical scales is of fundamental importance for our understanding of how organisms may adapt to their environments. Northern peripheral populations generally have lower genetic variation and individuals in these populations may therefore face difficulties adapting to their local environment. READ MORE

  5. 5. Diversity Underfoot Systematics and Biogeography of the Dictyostelid Social Amoebae

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Allison L Perrigo; Uppsala universitet.; [2013]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Amoeba; biogeography; cryptic species; dictyostelid; latitudinal gradient; multicellularity; protist; social amoeba; phylogenetics; systematics; new species; Biologi med inriktning mot systematik; Biology with specialization in Systematics;

    Abstract : Dictyostelids (Amoebozoa) are a group of social amoebae consisting of approximately 150 species, which are found in terrestrial habitats worldwide. They are divided into eight major clades based on molecular phylogeny, and within these clades are many species complexes. READ MORE