<p>In this thesis we have studied speciation in three butterfly genera <i>Polygonia</i> (Nymphalidae, Nymphalini), <i>Pararge </i>(Nymphalidae, Satyrinae) and <i>Celastrina</i> (Lycaenidae: Polyommatinae). In the first paper a dated phylogeny, based on molecular data, of <i>Polygonia</i> was constructed. We found strong conflict between the nDNA and mtDNA datasets. Possibly this can be explained by ancestral and recent hybridizations between contemporary taxa. The results point to the importance in using different markers when we try to resolve evolution of taxa. In the second paper a sister group comparison was made in order to discover whether host plant range has had an effect on species diversity in <i>Polygonia</i>. Our result indicated higher diversification rates in clades which included species with larvae feeding on different, or additional, plants compared to the ”urticalean rosids” specialists. In the third paper our focus was on the colonization abilities in polyphagous butterflies. The haplotype structures of the mtDNA <i>cytochromeoxidase I</i> (COI) within the Nearctic species of <i>Celastrina</i> as well as within<i> P. c-album</i> and <i>P. faunus</i> were analysed in a network. We found little variation in <i>Celastrina</i> and <i>P. c-album.</i> This results imply that the genera have expanded recently and rapidly. There are indications of differentiation in COI in <i>Celastrina</i> and, possibly, host plant use is involved. However, in <i>P.</i> <i>faunus</i> we found structure among the haplotypes. We believe that several different haplotypes of this species have been preserved during glaciations in the Nearctic. In the fourth paper the evolution of the grassfeeding <i>Pararge</i> was analysed. The phylogeny was based on the mtDNA COI and the nDNA <i>wingless</i> (wgl) and times of divergences were calculated. We found a deep divergence between the European and Moroccan populations of <i>P. aegeria</i> which indicates the importance of the Mediterranean as a barrier for gene flow. </p>

<p>A solid-phase extraction (SPE) method was developed for the determination of organochlorine pesticides, namely aldrin, alpha-BHC, beta-BHC, delta-BHC, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, lindane, heptachlor, heptachlor epoxide, 4,4’-DDD, 4,4’-DDE and 4,4’- DDT in water. The effect of extraction conditions, such as the addition of sodium chloride and methanol to the sample prior to loading was studied. The sample was concentrated by a plain polystyrene-divinylbenzene resin, and the extract was eluted by ethyl acetate. Qualification and quantification of the target pesticides were performedby gas chromatography/ mass spectrometry (GC/MS) in the full-scan and selected ion-monitoring mode, respectively, and for better detection of pesticides in field samples the mass spectrometer was altered from electron ionization (EI) to chemical ionization mode (CI). The repeatability of the method for MilliQ-water fortified with pesticides at a level of 0.1 to 0.6 µg/l ranged from 8 to 18%, and the obtained recoveries ranged from 67 to 135%. </p><p>The method was evaluated for the determination of organochlorine pesticides in fourteen surface- and groundwater samples taken from locations along King Talal Dam, King Abdullah Canal and Zarqa River in the Jordan Valley. The limit of detection of the pesticides residues in 500-ml field water samples ranged from 0.0009 to 15.7 ng/l. The obtained results confirmed the presence of trace amounts of some organochlorine pesticides in the analyzed samples, i.e. lindane and endosulfan compounds.</p>

<p>Virtually all diurnal birds have tetrachomatic vision based on four different colour receptors. As a result, birds are potentially able to perceive their environment in twice as many colours as humans and four times as many colours compared to most other mammals, which are dichromatic. In addition to the spectrum visible to humans, birds are able to detect ultraviolet (UV) light. Signals with a UV component have been shown to be important to birds both in foraging and colour signalling. Because of the superior colour discrimination of the avian eye, UV sensitivity, but especially owing to its tetrachromacy, we cannot know what birds look like to those that matter, i.e. other birds.</p><p>In my thesis I describe a new molecular method with which it is possible to identify the vision system of birds only using a small amount of DNA, without the need to keep or sacrifice the animal. It thereby facilitates large screenings, including rare and endangered species. The method has been used to increase the number of species with identified vision system type from 19 to 66. I show that raptors and songbirds have different vision systems, giving songbirds the possibility of a secret channel for colour signalling, and that male songbirds in coniferous forest take advantage of this to be significantly more cryptic to raptors than to females songbirds. I show that gulls have gained a vision system enabling them to detect the UV signals of fish when the fish swim close to the surface.</p><p>Even though we tend to be rather self-satisfied with the quality of our colour vision, we are colour-blind when compared to birds. My work shows that human colour vision is inadequate for judging animal coloration, and that there is much more going on in bird colour signalling than meets our eye.</p>

Virtually all diurnal birds have tetrachomatic vision based on four different colour receptors. As a result, birds are potentially able to perceive their environment in twice as many colours as humans and four times as many colours compared to most other mammals, which are dichromatic. In addition to the spectrum visible to humans, birds are able to detect ultraviolet (UV) light. Signals with a UV component have been shown to be important to birds both in foraging and colour signalling. Because of the superior colour discrimination of the avian eye, UV sensitivity, but especially owing to its tetrachromacy, we cannot know what birds look like to those that matter, i.e. other birds. In my thesis I describe a new molecular method with which it is possible to identify the vision system of birds only using a small amount of DNA, without the need to keep or sacrifice the animal. It thereby facilitates large screenings, including rare and endangered species. The method has been used to increase the number of species with identified vision system type from 19 to 66. I show that raptors and songbirds have different vision systems, giving songbirds the possibility of a secret channel for colour signalling, and that male songbirds in coniferous forest take advantage of this to be significantly more cryptic to raptors than to females songbirds. I show that gulls have gained a vision system enabling them to detect the UV signals of fish when the fish swim close to the surface. Even though we tend to be rather self-satisfied with the quality of our colour vision, we are colour-blind when compared to birds. My work shows that human colour vision is inadequate for judging animal coloration, and that there is much more going on in bird colour signalling than meets our eye.

A low content of organic matter, which is largely refractory in nature, is characteristic of most sediments, meaning that aquatic deposit-feeders live on a very poor food source. The food is derived mainly from sedimenting phytodetritus, and in temperate waters like the Baltic Sea, from seasonal phytoplankton blooms. Deposit-feeders are either bulk-feeders, or selective feeders, which preferentially ingest the more organic-rich particles in the sediment, including phytodetritus, microbes and meiofauna. The soft-bottom benthos of the Baltic Sea has low species biodiversity and is dominated by a few macrobenthic species, among which the most numerous are the two deposit-feeding amphipods Monoporeia affinis and Pontoporeia femorata, and the bivalve Macoma balthica. This thesis is based on laboratory experiments on the feeding of these three species, and on the priapulid Halicryptus spinulosus. Feeding by benthic animals is often difficult to observe, but can be effectively studied by the use of tracers. Here we used the radioactive isotope 14C to label food items and to trace the organic matter uptake in the animals, while the stable isotopes 13C and 15N were used to follow feeding on aged organic matter in the sediment. The abundance of M. balthica and the amphipods tends to be negatively correlated, i.e., fewer bivalves are found at sites with dense populations of amphipods, with the known explanation that newly settled M. balthica spat are killed by the amphipods. Whether the postlarvae are just accidentally killed, or also ingested after being killed was tested by labelling the postlarvae with 14C and Rhodamine B. Both tracer techniques gave similar evidence for predation on and ingestion of postlarval bivalves. We calculated that this predation was likely to supply less than one percent of the daily carbon requirement for M. affinis, but might nevertheless be an important factor limiting recruitment of M. balthica. The two amphipods M. affinis and P. femorata are partly vertically segregated in the sediment, but whether they also feed at different depths was unknown. By adding fresh 14C-labelled algae either on the sediment surface or mixed into the sediment, we were able to distinguish surface from subsurface feeding. We found M. affinis and P. femorata to be surface and subsurface deposit-feeders, respectively. Whether the amphipods also feed on old organic matter, was studied by adding fresh 14C-labelled algae on the sediment surface, and using aged, one-year-old 13C- and 15N-labelled sediment as deep sediment. Ingestion of old organic matter, traced by the stable isotopes, differed between the two species, with a higher uptake for P. femorata, suggesting that P. femorata utilises the older, deeper-buried organic matter to a greater extent. Feeding studies with juveniles of both M. affinis and P. femorata had not been done previously. In an experiment with the same procedure and treatments as for the adults, juveniles of both amphipod species were found to have similar feeding strategies. They fed on both fresh and old sediment, with no partitioning of food resources, making them likely to be competitors for the same food resource. Oxygen deficiency has become more wide-spread in the Baltic Sea proper in the last half-century, and upwards of 70 000km2 are now devoid of macrofauna, even though part of that area does not have oxygen concentrations low enough to directly kill the macrofauna. We made week-long experiments on the rate of feeding on 14C-labelled diatoms spread on the sediment surface in different oxygen concentrations for both the amphipod species, M. balthica and H. spinulosus. The amphipods were the most sensitive to oxygen deficiency and showed reduced feeding and lower survival at low oxygen concentrations. M. balthica showed reduced feeding at the lowest oxygen concentration, but no mortality increase. The survival of H. spinulosus was unaffected, but it did not feed, showing that it is not a surface deposit-feeder. We conclude that low oxygen concentrations that are not directly lethal, but reduce food intake, may lead to starvation and death in the longer term.

The social organization of animal societies has important implications for several fields of biology, from managing wild populations to developing new ecological and evolutionary theory. Although much attention has been given to the formation and maintenance of societies of group living individuals, less is known about how societies of solitary individuals have been shaped and maintained. Traditionally, the evolution of social organizations in the mammalian order Carnivora has been regarded as a directional selection process from a solitary ancestry into progressively more advanced forms of sociality. In this thesis, I tested this model against an alternative model, assuming radiation from a socially flexible ancestry. I further explored sociality, resource use and dispersal of a solitary carnivore, the wolverine (Gulo gulo), in the light of these two evolutionary models. Phylogenetic reconstruction generally supported that carnivore social organizations evolved through directional selection from a solitary ancestor. However, results from captive wolverine females indicated that they might have rudimentary social tendencies, which rather support that sociality in carnivores radiated from a socially flexible ancestry. Wild wolverines in northwestern Brooks Range, Alaska, adhered to the commonly found ecological niche as a largely ungulate dependent generalist carnivore. Lack of sexual asymmetry in dispersal tendencies indicated that resource competition among wolverine females probably was high. I suggest that wolverines have latent abilities to aggregate, but that their phylogenetic legacy in terms of morphology has constrained them into an ecological niche where resource abundance and distribution generally inhibit aggregations. Due to contradictory results, I suggest further research to test evolutionary theory regarding carnivore social evolution, and particularly to explore new avenues into social evolution that better explain intra-specific variation in sociality, as well as formation and maintenance of solitary social systems.

In this thesis we have studied speciation in three butterfly genera Polygonia (Nymphalidae, Nymphalini), Pararge (Nymphalidae, Satyrinae) and Celastrina (Lycaenidae: Polyommatinae). In the first paper a dated phylogeny, based on molecular data, of Polygonia was constructed. We found strong conflict between the nDNA and mtDNA datasets. Possibly this can be explained by ancestral and recent hybridizations between contemporary taxa. The results point to the importance in using different markers when we try to resolve evolution of taxa. In the second paper a sister group comparison was made in order to discover whether host plant range has had an effect on species diversity in Polygonia. Our result indicated higher diversification rates in clades which included species with larvae feeding on different, or additional, plants compared to the ”urticalean rosids” specialists. In the third paper our focus was on the colonization abilities in polyphagous butterflies. The haplotype structures of the mtDNA cytochromeoxidase I (COI) within the Nearctic species of Celastrina as well as within P. c-album and P. faunus were analysed in a network. We found little variation in Celastrina and P. c-album. This results imply that the genera have expanded recently and rapidly. There are indications of differentiation in COI in Celastrina and, possibly, host plant use is involved. However, in P. faunus we found structure among the haplotypes. We believe that several different haplotypes of this species have been preserved during glaciations in the Nearctic. In the fourth paper the evolution of the grassfeeding Pararge was analysed. The phylogeny was based on the mtDNA COI and the nDNA wingless (wgl) and times of divergences were calculated. We found a deep divergence between the European and Moroccan populations of P. aegeria which indicates the importance of the Mediterranean as a barrier for gene flow.

A solid-phase extraction (SPE) method was developed for the determination of organochlorine pesticides, namely aldrin, alpha-BHC, beta-BHC, delta-BHC, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, lindane, heptachlor, heptachlor epoxide, 4,4’-DDD, 4,4’-DDE and 4,4’- DDT in water. The effect of extraction conditions, such as the addition of sodium chloride and methanol to the sample prior to loading was studied. The sample was concentrated by a plain polystyrene-divinylbenzene resin, and the extract was eluted by ethyl acetate. Qualification and quantification of the target pesticides were performedby gas chromatography/ mass spectrometry (GC/MS) in the full-scan and selected ion-monitoring mode, respectively, and for better detection of pesticides in field samples the mass spectrometer was altered from electron ionization (EI) to chemical ionization mode (CI). The repeatability of the method for MilliQ-water fortified with pesticides at a level of 0.1 to 0.6 µg/l ranged from 8 to 18%, and the obtained recoveries ranged from 67 to 135%. The method was evaluated for the determination of organochlorine pesticides in fourteen surface- and groundwater samples taken from locations along King Talal Dam, King Abdullah Canal and Zarqa River in the Jordan Valley. The limit of detection of the pesticides residues in 500-ml field water samples ranged from 0.0009 to 15.7 ng/l. The obtained results confirmed the presence of trace amounts of some organochlorine pesticides in the analyzed samples, i.e. lindane and endosulfan compounds.

<p>In the scope of future population support, agricultural productivity, in particular in sub-Saharan Africa, has to increase drastically to meet the UN’s millennium development goals of eradicating extreme poverty and hunger by 2015. Water availability in the root-zone limits crop production in large parts of the developing world. As competition for fresh water increases, water of lower quality, for example saline or polluted water, is often used for irrigation. Low-cost drip systems are suitable for saline water irrigation because they effectuate a minimisation of salt accumulation, leaf burn and peaks in salt concentration. Nonetheless, all types of saline water irrigation contain the risk for causing soil salinisation. Thus, in order to achieve long-term sustainability of these systems, appropriate management strategies are needed. The choice of management practices may be influenced by local conditions such as climate, soil and irrigation water salinity. A litera-ture review showed that there is a potential for saline water irrigation in sub-Saharan Africa in water scarce areas. Low-cost drip irrigation with saline water (6 dS m-1) was successfully used to irrigate two consecutive crops of tomato in semi-arid South Africa. An integrated ecosystems model was developed to simulate long-term yield and salt accumulation in a drip-irrigated agricultural system for a range of salinities, climates and management techniques. Crop, salt and water balance data from two field experiments conducted in Israel and South Africa, respectively, were used to parameterise and test the model. Emphasis was placed on testing the usability of the model as a tool for evaluating the importance of certain plausible management options of low-cost, drip-irrigation systems. Therefore, particular focus was directed towards correctly describing soil salinity stress on plant growth and soil evaporation from a distributed (wetted and dry) surface. In addition, the model was developed to function for different climates without having to change any other parameters or variables except for the actual climatic data. Simulations were subsequently run over a 30-year period to study long-term yield and salt accumulation in the soil profile for two sites in South Africa, demonstrating the applicability of the model. Model simulations showed that high soil salinities reduced crop growth and thus increased both drainage and soil evaporation. Further, covering the soil with a plastic sheet led to a reduction of soil evaporation and a subsequent increase in both transpiration and drainage. Rainfall was crucial for the leaching of salts from the soil, and thus in regions with low levels of rainfall, a higher leaching fraction of supplied saline irrigation water has to compensate for the lack of rain. However, a high leaching fraction also causes large amounts of salt leaching, which could potentially pollute underlying groundwater and downstream ecosystems. This risk can be mitigated using mulching, which minimises non-productive water losses, thereby lowering irrigation water needs. The choice of irrigation water salinity, frequency of irrigation and soil coverage may differ between the farmer and the regional water manager due to different preferences. Furthermore, the study highlighted how environmental variables such as water use efficiency and radiation use efficiency can be used as indicators of system performance. Whereas the latter is first and foremost a general stress indicator, water use efficiency more precisely describes specific factors such as plant size, allocation patterns and evaporative demand, which will affect the exchange of carbon dioxide and water through the stomata.</p>

<p>During the last few decades, coral reefs have become a disappearing feature of tropical marine environments, and those reefs that do remain are severely threatened. It is understood that humans have greately altered the environment under which these ecosystems previously have thrived and evoloved. Overharvesting of fish stocks, global warming and pollution are some of the most prominent threats, acting on coral reefs at several spatial and temporal scales. Presently, it is common that coral reefs have been degraded into alternative ecosystem regimes, such as macroalgae-dominated or sea urchin-barren. Although these ecosystems could potentially return to coral dominance in a long-term perspective, when considdering current conditions, it seems likely that they will persist in their degraded states. Thus, recovery of coral reefs cannot be taken for granted on a human timescale. Multiple stressors and disturbances, which are increasingly characteristic of coral reef environments today, are believed to act synergistically and produce ecological surprises. However, current knowledge of effects of compounded disturbances and stress is limited. Based on five papers, this thesis investigates the sublethal response of multiple stressors on coral physiology, as well as the effects of compounded stress and disturbance on coral reef structure and function. Adaptive responses to stress and disturbance in relation to prior experience are highlighted. The thesis further explores how inherent characteristics (traits) of corals and macroalgae may influence regime expression when faced with altered disturbance regimes, in particular overfishing, eutrophication, elevated temperature, and enhanced substrate availability. Finally, possibilities of affecting the resilience of macroalgae-dominaed reefs and shifting the community composition towards a coral-dominated regime are explored.</p>