Search for dissertations about: "growing season length"

Showing result 11 - 15 of 18 swedish dissertations containing the words growing season length.

2. 11. Remote sensing phenology at European northern latitudes - From ground spectral towers to satellites

   Author : Hongxiao Jin; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Remote sensing; climate sensitivity.; calibration; ground spectral tower; Plant phenology index PPI ; northern latitude;

   Abstract : Plant phenology exerts major influences on carbon, water, and energy exchanges between atmosphere and ecosystems, provides feedbacks to climate, and affects ecosystem functioning and services. Great efforts have been spent in studying plant phenology over the past decades, but there are still large uncertainties and disputations in phenology estimation, trends, and its climate sensitivities. READ MORE

4. 12. Climate change effects on migratory birds and on the ecology and behaviour of the willow warbler (Phylloscopus trochilus)

   Author : Johanna Hedlund; Sven Jakobsson; Thord Fransson; Cecilia Kullberg; Sara Cousins; Martin Schaefer; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; climate change; bird migration; ecology; phenology; bird; avian; willow warbler; chaffinch; land use change; landscape ecology; historical ecology; etologi; Ethology;

   Abstract : Recent global climate change is influencing the behaviour and ecology of species worldwide. Birds are typical systems to study in this context, as they are often migratory and thus subjected to a variety of environmental effects. READ MORE

5. 13. Tree phenology modelling in the boreal and temperate climate zones : Timing of spring and autumn events

   Author : Cecilia Olsson; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Plant phenology in the boreal and temperate climate zones is synchronised with seasonal changes in temperature and photoperiod. For deciduous trees, timing of budburst and leaf colouring define the growing season length and express adaptations to trade-offs in growth and risks. READ MORE

6. 14. Population dynamics of the perennial weed species Sonchus arvensis L

   Author : Saghi Anbari; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Abstract : Sonchus arvensis L. is a perennial weed that is widely prevalent in annual crops in northern Europe and can cause substantial yield losses. The abundance of S. arvensis has increased recently, primarily due to expansion of organic farming and increased use of reduced tillage. READ MORE

7. 15. Population differentiation in Lythrum salicaria along a latitudinal gradient

   Author : Katarina Olsson; Jon Ågren; Susan Kalisz; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; additive genetic variance; clinal variation; evolutionary constraints; G matrix; genetic correlation; natural selection; pollen limitation; population differentiation; Ekologi; Terrestrial; freshwater and marine ecology; 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