Search for dissertations about: "growing season length"

Showing result 6 - 10 of 18 swedish dissertations containing the words growing season length.

2. 6. Spatial and temporal dynamics of subarctic birch forest carbon exchange

   Author : Michal Heliasz; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; mountain birch; eddy covariance; carbon budget; insect outbreak; forest expansion; temporal variability; spatial variability;

   Abstract : High northern latitudes are of special importance for the global carbon budget as they store large amounts of organic matter in the soil and are expected to be the most strongly affected by climate change. Here we investigate carbon exchange in the subarctic mountain birch forest growing on the limit where tree growth is possible. READ MORE

4. 7. Adaptation Along Environmental Gradients: an Evaluation of Physiological Mechanisms and Ecological Constraints

   Author : Beatrice Lindgren; Anssi Laurila; Jacob Höglund; Svante Winberg; Andrew Sih; Uppsala universitet; []
   Keywords : Biology; Rana temporaria; latitudinal clines; growth rate; growth efficiency; SMR; predation; competition; trade-off; Biologi;

   Abstract : For ectotherms living in seasonal environments, time available for development and growth is often constrained by the length of the growth season. Declining season length towards higher latitudes often select for latitudinal clines in development and growth rates, exhibiting increasing growth and developmental rates towards the north. READ MORE

5. 8. Polyacetylenes - in organic and biodynamic carrots

   Author : Lars Kjellenberg; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Abstract : Falcarinol type polyacetylenes (FaTP) in carrots have been assigned both positive health effects and negative effects on taste, in connection with human consumption. The aim of this thesis was to contribute to the description of factors influencing the concentrations of FaTP in carrot. READ MORE

6. 9. Genetic Variation and Evolution of Floral Display in Primula farinosa

   Author : Camille Madec; Jon Ågren; Johan Ehrlén; Richard Ennos; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; natural selection; flowering time; population differentiation; local adaptation; male reproductive success;

   Abstract : In this thesis, I combine molecular analyses, common-garden and field experiments to examine how evolutionary and ecological processes influence patterns of genetic variation among and within populations of the declining, insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically I examined 1) whether genetic diversity at neutral marker loci was related to habitat fragmentation and habitat stability, 2) whether floral display and flowering time were more strongly differentiated among populations than were putatively neutral marker loci, 3) whether adaptive population differentiation could be detected on a local spatial scale, and 4) whether floral display differentially affected male and female reproductive success. READ MORE

7. 10. Population divergence at different spatial scales in a wide-spread amphibian

   Author : Patrik Rödin Mörch; Anssi Laurila; Jacob Höglund; Bengt Hansson; Uppsala universitet; []
   Keywords : Adaptive divergence; environmental gradients; genomics; life-history; amphibians; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

   Abstract : To study the distribution of genetic and phenotypic variation in different environments and at different spatial scales is important in order to understand the process of local adaptation and how populations will respond to future climate change. In my thesis I study populations of moor frogs (Rana arvalis) at different spatial scales, first along a 1700 km latitudinal gradient (Paper I, II, IV) and, second, in a system of inter-connected wetlands (III, IV). READ MORE