Mating strategies and sexual conflicts in aquatic invertebrates: consequences for evolutionary differentiation

In this thesis I investigated how mating related strategies may differ among populations and how these strategies evolve in response to their local ecological environments. I have used two different study systems of aquatic invertebrates: diving beetles (Dytiscidae) and the fresh water isopod Asellus aquaticus. These systems have in common that they present distinct genetic variation within the species: female polymorphism in the diving beetles and the occurrence of two ecotypes in the isopod. They also have in common that they are suggested to experience a conflict between the sexes over mating. In particular, I have addressed (i) how genetic polymorphism may be maintained in populations experiencing sexual conflict, (ii) the selection pressures acting on female polymorphism in diving beetles, (iii) the physical performance of the sexually antagonistic traits in diving beetles, (iv) parallel divergence and life-history consequences of precopulatory mate guarding in the two isopod ecotypes and (v) phenotypic plasticity in mating behaviour in response to demographic factors in the isopod ecotypes. I have also addressed the problem of how sexual conflict theory is conceptualised with regard to sex roles (vi). In my studies I have seen that behaviour and mating traits are to a large extent affected by ecological and demographic features. Within a species, the mating dynamics could differ dramatically between different populations and the evolutionary change in mating characteristics may be rapid. Mating characteristics can also change in parallel due to ecological similarities between populations. In the last study of this thesis it is shown that both the terminology and the features assigned to the sexes in theoretical models are highly sex-specific, and may reflect a stereotypic view of the sexes based on human sex roles

The effects of host plant species and larval density on immune function in the polyphagous moth Spodoptera littoralis

Immune functions are costly, and immune investment is usually dependent on the individual's condition and resource availability. For phytophagous insects, host plant quality has large effects on performance, for example growth and survival, and may also affect their immune function. Polyphagous insects often experience a large variation in quality among different host plant species, and their immune investment may thus vary depending on which host plant species they develop on. Larvae of the polyphagous moth Spodoptera littoralis have previously been found to exhibit density-dependent prophylaxis as they invest more in certain immune responses in high population densities. In addition, the immune response of S. littoralis has been shown to depend on nutrient quality in experiments with artificial diet. Here, I studied the effects of natural host plant diet and larval density on a number of immune responses to understand how host plant species affects immune investment in generalist insects, and whether the density-dependent prophylaxis could be mediated by host plant species. While host plant species in general did not mediate the density-dependent immune expression, particular host plant species was found to increase larval investment in certain functions of the immune system. Interestingly, these results indicate that different host plants may provide a polyphagous species with protection against different kinds of antagonisms. This insight may contribute to our understanding of the relationship between preference and performance in generalists, as well as having applied consequences for sustainable pest management

The effect of Silene acaulis on soil bacterial communities across elevational and latitudinal gradients in Scandinavia

Microbes are ubiquitous, extremely diverse, and contribute to important ecosystem functions. Soil bacterial communities, in particular, play an important role in carbon and nutrient cycling, through decomposition and carbon sequestration. In addition, soil bacteria establish mutualistic relationships with plants, animals and other microorganism. However, soil microbial communities may change in diversity and composition in response to changes in climate, which may disrupt the interactions between soil microbes and other organisms, such as plants. The impact of climate change in arctic and alpine environments is expected to be disproportionately large, thus it is important to understand how soil microbial communities in these environments respond to changes in temperature, precipitation, and plant communities. The alpine cushion plant Silene acaulis, is a dominant, foundational species known for its facilitative effects in stressful environments. There have been several studies investigating the facilitative effects of cushion plants on other plants. However, less in known about the relationship between cushion plants and their soil microbiome. Here, I investigated the effect of S. acaulis on its soil bacterial community. I also investigated the effect of latitude and elevation on the soil bacterial communities in rhizosphere of S. acaulis, as proxies for climate change. I found that S. acaulis had a significant effect on the soil bacterial community composition. Along the elevational gradient, soil microbial communities under S. acaulis decreased in richness with increases in elevation. There was a significant effect from latitude on the bacterial composition. However, it appears that site specific factors, such as pH, are more influential along the latitudinal gradient. S. acaulis may have a converging effect on the soil bacterial community composition along environmental gradients, and as such, the direct effects of climate change may be weak. Further research is needed to better understand the relative importance of the different factors driving soil bacterial communities in alpine environments.M-ECO

Biodiversity in interaction with historical values at Sofiero castle

”Biologisk mångfald i samspel med historiska värden på Sofiero slott” är ett självständigt arbete i landskapsarkitektur vid Sveriges Lantbruksuniversitet i Alnarp. Arbetet behandlar Sofieros historia, historiska värden på platsen, samt hur dessa värden har en positiv inverkan på den biologiska mångfalden. Syftet med arbetet är att undersöka hur Sofieros slottsträdgård gynnar den biologiska mångfalden och på vilket sätt parken tidigare har kunnat gynna biodiversitet genom gestaltning, växtmaterial och skötsel. En litteraturstudie utfördes för att ta reda på Sofieros trädgårdshistoria och för att samla information om biologisk mångfald samt bevarandet av historiska trädgårdar. Intervjuer med nyckelpersoner gav inblick i hur man på Sofiero jobbar med biologisk mångfald, och en inventering med platsanalys på tre olika områden i parken utfördes för att få en förståelse för platsen och hur den förändrats med tiden. Att främja den biologiska mångfalden i anläggningar där man måste bevara och anpassa sig till ett kulturhistoriskt trädgårdsarv är fullt möjligt. Eftersom Sofiero slottsträdgård delvis ger intrycket av en klassisk, engelsk landskapspark men även har strikta, trädgårdslika delar med museal karaktär finns det stor variation i hur parken upplevs. Det kräver kunskap, engagemang och konsekvensanalytiskt tänkande eftersom områdenas olika karaktär spelar roll i vilka åtgärder man kan införa för att främja biodiversiteten. På Sofiero arbetar man med att främja biodiversiteten på ett sätt som passar den omgivande miljön, och vill skapa förutsättningar för naturen att själv reglera diversiteten. Biologisk mångfald gynnas inte enbart av vilda och naturlika miljöer, en paradrabatt med lång blomningstid med variation i blomformer och med inslag av täta buskage kan vara minst lika gynnande för det biologiska livet som en skogsglänta i en ravin. Analyser som tidigare gjorts av liknande herrgårdsparker på tidigare jordbruksland har visat att den biologiska mångfalden i regel är större här än i omgivande skogspartier.“Biodiversity in interaction with historical values at Sofiero castle” is a bachelor thesis in landscape architecture at the Swedish University of Agricultural Sciences in Alnarp. The study is regarding the history of Sofiero castle, historical values at the site, and how these values have a positive impact on biodiversity. The purpose of this thesis is to investigate how Sofiero gardens can benefit biodiversity and in what way the park previously have been able to promote biodiversity through design, plant material and management. A literature study was conducted to understand the history of Sofiero gardens, and to gather information on biodiversity and the preservation of historical gardens. Interviews with key persons gave insight on how Sofiero deals with biodiversity, and an inventory with site analysis in different areas of the park was conducted to gain an understanding of the place and how it has changed over time. Promoting the biodiveristy in sites where you have to adapt to the preservation of the historical garden heritage is entirely possible. As Sofiero gardens partly give the impression of a classical English landscape but also have strict, garden-like parts with a museum character, there is great variety in how the park is experienced. It requires knowledge, commitment and impact-analytical thinking because of the different nature of the areas that play a role in the measures that can be introduced to promote biodiversity. The staff at Sofiero work to promote biodiversity in a way that suits the surroundings of the area in question, and often want to create conditions where nature itself regulates biodiversity. Biodiversity is not only favored by wild and natural looking plantings, a formal border with a long flowering period, variation in flower forms and elements of dense shrubbery can be as beneficial to ecological life as a forest glade in a ravine

Energy Price Stability: The Peril of Fossil Fuels and the Promise of Renewables

In "Energy Price Stability: The Peril of Fossil Fuels and the Promise of Renewables," authors Lauren Melodia and Kristina Karlsson demonstrate that volatile fossil fuel prices are a key driver of overall inflation and have historically triggered recessions. They argue that the Federal Reserve has little power to mitigate inflation driven by fossil fuel prices and that the solution to ongoing energy price volatility is a government-led investment in renewable energy production and deployment. Specifically, they conclude that:A transition away from fossil fuels toward renewable energy will have a stabilizing effect on prices, for two reasons:Renewable energy will bring the majority of our energy consumption into the electricity sector, a highly regulated sector that has historically produced stable energy prices; andRenewables are inherently stable compared to fossil fuels. A transition to renewable energy can improve existing inequities in energy burdens among renters, and among low-income, Black, and Latinx households

Predator faunas past and present: quantifying the influence of waterborne cues in divergent ecotypes of the isopod Asellus aquaticus

Waterborne chemical cues are an important source of information for many aquatic organisms, in particular when assessing the current risk of predation. The ability to use chemical cues to detect and respond to potential predators before an actual encounter can improve prey chances of survival. We investigated predator recognition and the impact of chemical cues on predator avoidance in the freshwater isopod Asellus aquaticus. This isopod has recently colonised a novel habitat and diverged into two distinct ecotypes, which encounter different predator communities. Using laboratory-based choice experiments, we have quantified behavioural responses to chemical cues from predators typical of the two predator communities (larval dragonflies in the ancestral habitat, perch in the newly colonised habitat) in wild-caught and lab-reared Asellus of the two ecotypes. Individuals with prior experience of predators showed strong predator avoidance to cues from both predator types. Both ecotypes showed similar antipredator responses, but sexes differed in terms of threat-sensitive responses with males avoiding areas containing predator cues to a larger extent than females. Overall, chemical cues from fish elicited stronger predator avoidance than cues from larval dragonflies. Our results indicate that in these isopods, prior exposure to predators is needed to develop antipredator behaviour based on waterborne cues. Furthermore, the results emphasise the need to analyse predator avoidance in relation to waterborne cues in a sex-specific context, because of potential differences between males and females in terms of vulnerability and life history strategies

Parkering i den hållbara staden- om parkeringens förhållande till Malmös visioner till en hållbar stadsutveckling

Today, most cities and municipalities in Sweden have objectives and visions of a sustainable urban development. The idea of “the sustainable city” usually contains a city that is green, densely built, have a variety of housing, a developed public transport system and good conditions for walking and cycling. During recent years, more and more critics argue that the way we plan for parking in cities counteracts these sustainability values. This study is based on a case study of Malmö and seeks to analyse the relationship between Malmö’s visions of sustainable urban development and today’s parking regulations. The study concludes that parking is a complex and multi-layered issue and that the relationship between parking and “the sustainable city” contains a variety of conflicts

Effekter av olika tillväxthastigheter under kalvperioden

Rekryteringsdjur i svenska mjölkkobesättningar har traditionsmässigt inte blivit uppmärksammade. Tiden från födsel till inkalvning ses ofta som en kostsam transportsträcka. Det är först när de börjar avkasta mjölk och generera pengar till gården som de börjar bli av intresse. På Alnarps försöksgård, Mellangård, genomfördes det 2000-2001 en tillväxtstudie på kalvar under mjölkperioden. Totalt ingick 62 kalvar, hälften fick en hög mjölkgiva och resterande fick en lägre mjölkgiva. Det gav två grupper, en med hög tillväxt (H) och en med lägre tillväxt (L). Under kvigperioden fick alla kvigor samma utfodring oavsett tidigare grupp. Nedan följer en sammanställning av tidigare försöksresultat som visar tendenser hur en god jämfört med normal tillväxt på kalv och kviga påverkar den framtida kon. Från den dagen kalven föds är det viktigt att vara målmedveten med dess uppväxt. Det är många saker som påverkar kalvens hälsa så som inhysnings- och utfodringssystem, fodrets konsistens och kvalité som i sin tur påverkar kalvens tillväxt. För den nyfödda kalven är det oerhört viktigt att få i sig rätt mängd råmjölk i rätt tid. Råmjölken hjälper kalven bygga upp sitt immunförsvar som i sin tur minskar risken för sjukdom hos kalven vilket kan leda till minskad tillväxt. De vanligaste kalvsjukdomarna är diarré och lunginflammation. Då kvigan har en stor tillväxtpotential under kalvperioden är den perioden viktig att ta vara på för att få kalven att utvecklas och växa maximalt. Det rekommenderas att kalven bör ha en daglig tillväxt på minst 650g. Kalvarna i det försöksmaterial som vi sammanställt har haft en tillväxt mellan 537-986 g/dag. Andra försök har visat att kalvar med en hög tillväxt, runt 1000 g/dag, har vid sin första laktation gett en högre avkastning än de kalvar som haft en betydligt lägre tillväxt under mjölkperioden. Kalvarna som ingått i detta projekt har inte visat någon tendens att de skulle ge en högre avkastning. Det är viktigt att visa på de effekter som olika skötsel- och utfodringsstrategier till kalvar och kvigor har på den blivande kon. När kvigan är mellan 3-13 månader säger man att hon befinner sig i den kritiska perioden, då är risken stor att hon vid överutfodring ansätter fett i juvret med en låg avkastning som följd. Svenska rekommendationer har länge varnat för effekterna av en för hög tillväxt under denna period, max 650-750g/dag. Följderna av detta är att svenska mjölkproducenter blivit restriktiva i sina foderstater till rekryteringskvigor då rädslan för överutfodring varit stor. Det har fått till följd att många kvigor underutfodrats av framförallt proteinfodermedel. Det finns mycket forskning inom ämnet och det tvistas hur kritisk perioden egentligen är. Det finns forskare som menar på att den kritiska perioden finns men den genetiska kapaciteten för tillväxt har ökat. De menar på att det djurmaterial som finns i dagsläget tål högre tillväxt under den kritiska perioden än de djur som fanns när de första upptäckterna gjordes. Sammanställningen vi har gjort av material på tillväxt under kritiska perioden och den framtida avkastningen visar ingen tendens att den kritiska perioden skulle påverka avkastningen så länge tillväxten inte överstiger 1000g per dag. Försök har visat på att lägre inkalvningsålder ger en lägre avkastning. Det har ofta att göra med att ett äldre djur är mer utvecklat och har en högre vikt, vilket i sin tur har ett positivt samband med avkastningen. Det ska dock inte glömmas bort att ställa den något lägre avkastningen mot den högre uppfödningskostnaden för en äldre kviga. Det finns kalkyler, på hur mycket det kostar att föda upp kvigan, som visar på hur mycket man kan spara på att låta kvigan kalva in tidigare. Dock så måste kvigan vid inkalvning ha uppnått tillräcklig vikt så att man får en väl fungerande och hållbar ko. Materialet från försöket på Mellangård har sammanställts för att illustrera hur inkalvningsvikt och inkalvningsålder påverkar mjölkavkastningen. Det visar en tendens på att, precis som det nämns ovan, att en högre inkalvningsålder ger en högre avkastning. Dock visar sammanställningen ingen tendens på att vikten vid inkalvning skulle påverka avkastningen inom det tillväxtintervallet som undersöktes. Grupperna med hög (H) respektive låg (L) tillväxt jämfördes när det gällde registrerade behandlingar, antal laktationer och utslagsorsak. I rapporter från försöket beskrevs det att kvigorna med en högre inkalvningsålder än 25 månader visade en klar tendens till fler kalvningssvårigheter. Grupp H visar på 43 % av det totala antalet registrerade sjukdomar och grupp L 57 %. Antalet laktationer har jämförts med tillväxten dag 0-90. Den tendens som går att utläsa av tabellen är avsaknaden av kvigor med hög tillväxt och många laktationer. Utslagsorsakerna av djuren har sammanställts, grupperna är uppdelade var för sig. Det bör nämnas att Mellangård drabbades av salmonella hösten 2005 och sommaren 2006 slogs samtliga kor ut. Därför är det svårt att klargöra några tendenser både vad det gäller antal laktationer och utslagsorsaker.In Swedish dairy herds, replacement heifers have never been a big economical factor until they calf and start their milk production. The time from their birth until their first calf are considered an expensive transportation route. Normally producers don’t consider the quality of feed and the heifer’s daily gain during this period an important issue. A study about female calves daily weight gain was made at Alnarps research farm, Mellangård, in the year 2000-2001. In total 62 calves were studied and they were assigned to two different treatments during their neonatal period. This gave two groups with different daily weight gain (L with lower and H with higher). One of these groups was fed a higher amount of milk than the other group. During their pre- and post pubertal period both groups were fed exactly the same. The following will show a compilation of data that shows the differences in a cow’s future production based on their daily gain as calves. It is very important that the producer have a very fixed purpose with the calf’s upbringing from day one. There are many things that affect the calf’s health, like for example feeding and housing systems and the quality of food which in their turn affect the calf’s daily gain. For the new born calf it is extremely important that it is fed the right amount of colostrum as soon as possible. Colostrum secures the calves immunity which lowers the risk for disease and thereby also the risk for lower daily gain. Diarrhea and pneumonia are the most common diseases for calves. The potential for heifer’s daily gain is very high during the neonatal period, because of this it is very important to take advantage of this and make sure that the daily gain is maximal. The recommended daily gain is a minimum of 650 g per day. The calves in the material we have studied had an average daily gain between 537 and 986 g per day. Other studies show that calves with a higher daily gain (average 1000 g per day) produce more milk during their first lactation than calves that had lower daily gain. Although, the calves in this study does not show any difference that they should produce more milk. It is very important to show that the effects that different feeding strategies and housing systems used for calves make a big difference on the future cow. When the heifer is between 3 and 13 months old is considered critical period. The risk of overfeeding that leads to a fattening udder and low milk production is during this period very big. For a long time swedish recommendations has said that the effects from a high daily gain might be critical during this period and recommend a daily gain of maximum 650-750 g per day. Because of this Swedish dairy farmers have been careful about not feeding their heifers too much, which has led to many underfed heifers especially considering protein intake. A lot of research has been made in the area and scientists still argue about how critical this period really is. Some scientists say that the critical period exists, but the genetical capacity for daily gain has increased. They say that the material of animals bred today endure a higher daily gain during the critical period than the animals bred when scientist first discovered the critical period. This compilation shows that the daily gain during the critical period will not affect future milk production as long as the daily gain is not higher than 1000 g per day. Studies have showed that heifers that have lower age at calving get a lower milk production subsequently. Because older animals are heavier and more developed they produce more milk. One important issue that should not be forgotten is that the older heifers have a higher rearing cost. Calculations show how much a heifer costs in rearing and how much a producer can save by letting the heifer calf at lower age. Important to consider when calving heifers at lower age is the balance between a well grown, well working and longevity. The material from the studies at Mellangård has been compiled to weight at calving and age at calving in proportion to future milk production. It shows that just as mentioned before, a higher age at calving gives a higher future milk production. It does not show anything about if the weight at calving affects the future milk production (figure 4). The different groups with high and low daily gain were compared registered treatments, number of lactations and cause of death. Rapports from the studies showed that the heifers older than 25 months at calving had more difficulties at calving. Table 9 shows this and the groups registered diseases compared to each other. Group H shows a total of 43% of the registered diseases and group L 57%. The number of lactations is compared with the average daily gain day during 0-90 days. It shows that there are very few heifers with a high daily gain and many lactations. The causes of death have been compiled, the groups have been divided. We also want to mention that Mellangård suffered salmonella in the fall of 2005 and in the summer 2006 the entire herd was killed off. This makes it hard to define any tendencies considering lactations and causes of death

Extrusion parameters for foaming of a beta-glucan concentrate

Plastics is a group of materials commonly encountered on a daily basis by many people. They have enabled rapid, low-cost manufacturing of products with complicated geometries and have contributed to the weight reduction of heavy components, especially when produced into a foamed structure. Despite the many advantages of plastics, some drawbacks such as the often fossil-based raw-material and the extensive littering of the material in nature, where it is not degraded for a very long time, needs to be dealt with. One way to address at least one of the issues could be to use polymers from nature instead of fossil-based ones. Here, a β-glucan concentrate originating from barley was investigated. The concentrate was processed into a foam by hot-melt extrusion, and the processing window was established. The effect of different blowing agents was also investigated. Water or a combination of water and sodium bicarbonate were used as blowing agents, the latter apparently giving a more uniform pore structure. The porous structure of the foamed materials was characterized mainly by using a combination of confocal laser scanning microscope and image analysis. The density of the samples was estimated and found to be in a similar range as some polyurethane foams. A set of 3D parameters were also quantified on two selected samples using X-ray microtomography in combination with image analysis, where it was indicated that the porous structure had a pre-determined direction, which followed the direction of the extrusion process

Odors Attracting the Long-Legged Predator Medetera signaticornis Loew to Ips typographus L. Infested Norway Spruce Trees

Predatory long-legged flies of the genus Medetera are important, but currently understudied, natural enemies of Scolytinae bark beetles such as Ips typographus. Medetera flies lay eggs on beetle-infested trees, where the developing larvae find their prey, but the chemical cues used by Medetera to locate infested trees are currently unknown. To identify odors attracting Medetera signaticornis, a species in Europe, headspace samples were collected at several time-points through different stages of I. typographus attacks on logs of Norway spruce (Picea abies). The headspace samples were analyzed using combined gas chromatography and mass spectrometry (GC-MS), and gas chromatography coupled with electroantennographic detection (GC-EAD) to determine compounds that stimulate M. signaticornis antennae. Antennae of M. signaticornis males and females were found to detect (-)-cis-verbenol, (+)-trans-verbenol and myrtenol, which are known to be produced by bark beetles. Antennal responses were also observed for verbenene, isoterpinolene, alpha-pinene oxide, camphor, pinocamphone, terpinene-4-ol, myrtenal, borneol, alpha-terpineol, geranyl acetone, and verbenone, which are primarily produced by microorganisms, and alpha-pinene, alpha-fenchene, beta-pinene, camphene, 3-carene, limonene, gamma-terpinene, and terpinolene, known spruce tree compounds. In field experiments testing two synthetic blends containing 18 antennal active and two additional compounds 2-methyl-3-buten-2-ol and ipsdienol we observed significant attraction of M. signaticornis within 24 h. These attractive blends can form the basis for development of Medetera monitoring lures for use in future forest and pest management