Sökning: "stable isotopes"
Visar resultat 16 - 20 av 146 avhandlingar innehållade orden stable isotopes.
16. Climate in the eastern Mediterranean during the Holocene and beyond – A Peloponnesian perspective
Sammanfattning : This thesis contributes increased knowledge about climate variability during the late Quaternary in the eastern Mediterranean. Results from a paleoclimate review reveal that regional wetter conditions from 6000 to 5400 years BP were replaced by a less wet period from 5400 to 4600 years BP and to fully arid conditions around 4600 years BP. LÄS MER
17. Tools for Evaluating the Fate and Bioaccumulation of Organic Compounds in Aquatic Ecosystems
Sammanfattning : The bioaccumulation of organic contaminants in aquatic ecosystems has been a key focus in environmental toxicology over the last decades. Bioaccumulation is a key concept in ecological risk assessments since it controls the internal dose of potential environmental contaminants. LÄS MER
18. Late Quaternary climate and environmental change in the summer rainfall region of South Africa : A study using trees and wetland peat cores as natural archives
Sammanfattning : This thesis contributes with information on past climate and environmental changes in South Africa’s summer rainfall region. The study is based on multi-proxy analyses on wetland peat cores and analyses of stable isotope composition (δ13C, δ18O) and wood anatomy in cross sections from subtropical trees (Breonadia salicina). LÄS MER
19. Ecology of red admiral migration
Sammanfattning : The red admiral (Vanessa atalanta) is a migratory butterfly that can be found in North America, North Africa, Europe and some parts of Asia. In Europe the main part of the population spend winter in the Mediterranean region and the following spring leave this area to breed further to the north. LÄS MER
20. Causes and consequences of niche differentiation between color morphs of pygmy grasshoppers
Sammanfattning : In this thesis, I used the color polymorphic pygmy grasshopper, Tetrix subulata, as a model system in order to investigate the degree of niche differentiation between alternative color morphs that are present within a single population. First, I hypothesized that individuals belonging to different color morphs differ in their innate food preference due to somewhat dissimilar physiology, and in their actual food consumption due in part to differential habitat use. LÄS MER
