Sökning: "Plant Ecology"

Visar resultat 11 - 15 av 370 avhandlingar innehållade orden Plant Ecology.

1. 11. Plants go with the flow : predicting spatial distribution of plant species in the boreal forest

   Författare :Ursula Zinko; Christer Nilsson; Håkan Rydin; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; boreal forest; vascular plant; species richness; wetness index; soil pH; bryophyte; lichen; substrate; stand age; plot size; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : The main objectives of this thesis are to study if a topographic wetness index (TWI) could be used as a tool for predicting the spatial distribution of vascular plant species richness in the boreal forest as well as to study congruence in species richness between vascular plants, liverworts, mosses and lichens. A wetness index ln(a/tanβ) based on topography was used to assign a specific TWI-value to every 20 x 20m grid in two 25 km2 boreal forest landscapes (differing in average soil pH) in northern Sweden. LÄS MER

3. 12. Distribution Patterns and Metapopulation Dynamics of Epiphytic Mosses and Lichens

   Författare :Tord Snäll; Håkan Rydin; Johan Ehrlén; Christine Ray; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; plant; metapopulation; model; parameterization; connectivity; dispersal; colonization; extinction; epiphytic; bryophyte; lichen; boreal; fragmentation; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : This thesis examines the relative importance of local conditions, dispersal and dynamics of the trees on epiphyte distribution patterns and colonization-extinction dynamics. Study species are the mosses Orthotrichum speciosum and O. obtusifolium, and the red-listed Neckera pennata. LÄS MER

4. 13. Variation in Pseudorchis albida s.l. (Orchidaceae) and Carex capitata s.l. (Cyperaceae) : Morphology, genetic diversity, ecology and systematics

   Författare :Lars-Gunnar Reinhammar; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Pseudorchis; Carex; morphologic variation; allozymes; immigration history; regeneration niche; biodiversity; ordinations; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; systematisk botanik; Systematic Botany;

   Sammanfattning : In the Scandinavian flora, several species-pairs where one member is an alpine species andthe other is a closely related lowland species, have been described. The aim of this studywas to investigate two such examples, viz. Pseudorchis albida s.s. LÄS MER

5. 14. PLANT-BACTERIAL AND PLANT-FUNGAL COMPETITION FOR NITROGEN AND PHOSPHORUS

   Författare :Katarina Månsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Amino acid; 15N; Soil C:N ratio; Plant ecology; Soil drying-rewetting;

   Sammanfattning : Competition between and within species has been one of the most studied concepts in ecology. In this thesis the aim was to test the idea of plant-microbial competition for N and, by studying this interaction, to gain a better understanding of different N processes in soil. LÄS MER

7. 15. Insect Diversity in Changing Landscapes

   Författare :Markus Franzén; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; växtparasitologi; Entomologi; plant parasitology; Zoology; Zoologi; Entomology; Ekologi; Ecology; butterfly; bee; dispersal; extinction; Djurekologi; Animal ecology;

   Sammanfattning : During recent decades, concern about the loss of biodiversity has increased. To change this negative trend there is an urgent need for effective conservation measures and there are ample evidence that conservation of organisms without an understanding of their ecology and behaviour is impossible. LÄS MER