Freshwater mussels are aquatic organisms that are involved in nutrient cycling and water purification. Freshwater mussels have filtering activity and transfer nutrients and energy-rich organic compounds from the water column to the sediments. Besides this activity, freshwater mussels are among the most important water pollution indicators due to their ability to concentrate many environmental contaminants such as heavy metals. The genome of most freshwater mussels has not yet been sequenced. The knowledge about the genome of the freshwater mussel's species can be useful to develop a multi-biomarker panel for early indication of water pollution. This study aimed to sequence the whole genomic DNA of freshwater mussel Unio tumidus using the MinION device. In this study, a total of 6 Gb data and 194 contigs with a total length of 825,486bp were generated while the length of the largest contig was 35,755 and the GC content 37.66% and N50 11647 bp was obtained. The generated data was not enough to assemble the whole genome of the mussels' species, and just a partial sequence could be obtained because of many challenges during the DNA extraction and library preparation. However, to obtain the whole DNA composition of these species making more effort, such as performing more library preparation and sequencing runs, are required, but the finding of this study can be used for the generation of more sequencing data for the assembly of the full genome.

The ongoing shrubification of the Arctic tundra may in the future have serious consequences for the ecosystem. More trees and shrubs will lead to changes in species composition and may alter diversity, carbon and nutrient balance, and result in a lower albedo. Reindeer can reduce the spread of shrubs, but plants have developed chemical defenses against herbivores made up of secondary metabolites. The concentration of these can be affected by several factors, including damages from herbivory and the availability of nutrients. In this study samples of the shrub B. nana ssp. nana (dwarf birch) and soil samples were collected from outside and inside herbivore exclosures in Fennoscandia. Then, concentrations of phenols and terpenes, the major defense component in birches, and soil nutrient availability were analyzed. A proxy was created for measuring the density of reindeer at each location. The aim was to evaluate this data and see if the exclusion of herbivores or the nutrient availability had any effect on the concentration of the defense components. Few differences between the exclosures and control plots could be found and only two out of 18 t-tests showed any difference that was deemed statistically significant. The density of herbivores was found to have no effect and the nutrient availability showed no clear results. This study concludes there are many factors influencing the concentration of defense components in dwarf birches, including the rising temperatures, that need to be considered in future studies. A better understanding of this subject would be essential in visualizing the future of the Arctic tundra.

No description available.

Strandzoner är heterogena miljöer formade av regelbundna störningar och präglade av hög artrikedom och många viktiga ekosystemfunktioner. Flertalet studier lyfter fram växters förmåga att sprida sina frön med vatten som en viktig faktor bakom sammansättningen av växtsamhällen längs med vattendragens strandbankar. En successiv tillförsel av arter längs med älvnätverkens vattenfåror borde leda till en högre artrikedom nedströms längs älvarna. Vattendragens naturliga fluktuationer i vattenstånd skapar förutsättningar för frön att deponeras över strandzonerna, fluktuationer som är påverkade i reglerade älvar. I denna studie inventerades kärlväxter i strandzonslokaler längs huvudfårorna av en reglerad och en oreglerad älv i norra Sverige för att undersöka mönster av artrikedom och diversitet nedströms längs vattendragen. Inventeringsobjekten var placerade innan och efter mynningen av anslutande biflöden längs älven för att undersöka om artrikedomen vid huvudfårans strandzoner påverkades av tillförsel av spridningsenheter från biflödena. Resultaten visade ingen signifikant ökning av växtsamhällenas artrikedom närmare älvarnas utlopp. För den oreglerade älven visade sig artdiversiteten tvärtom minska nedströms längs vattendraget. Endast sju av tretton lokaler visade på en förhöjd artrikedom efter anslutande biflöden vilket inte visar på någon betydande effekt. Variationen i artrikedom och diversitet var stor mellan lokalerna längs älvarna vilket tyder på att andra, lokala faktorer, har större effekt för etablering och sammansättning av älvarnas växtsamhällen. / Riparian zones are heterogeneous environments influenced by natural disturbances and characterized by high species richness and essential ecosystem functions. Many studies emphasize the ability of plants to disperse their propagules by water as an important factor for the composition of plant communities along riverbanks. The accumulation of propagules from species pools in upstream locations should lead to a higher species richness further downstream along a river. Seasonal flooding helps to disperse and distribute the propagules over the riverbeds, a function that is altered in many regulated rivers. In this study, vascular plants were inventoried in the riparian zones of main stems of one regulated and one free flowing river in northern Sweden to investigate the patterns of species richness and diversity along the course of these streams. Sample plots were located before and after the confluence of tributaries along the main stem to be able to determine if species richness in the riparian zone of the river was influenced by dispersal from the tributaries. The result did not show any significant increase in species richness closer to the coast in the river system. Only seven out of thirteen plots showed increased species richness downstream of the tributaries, which did not support the relation between species richness and position along the stream. Variation in species richness and diversity among sites was high, indicating that other local conditions probably had larger effects on the composition of the plant communities along the rivers.

Kunskap om fiskars diet är viktigt för att kunna bedriva en ekosystembaserad fiskförvaltning. I Sveriges största sjö Vänern lever glacialrelikta stammar av lax (Salmo salar) och öring (Salmo trutta) som enligt Natura 2000 har särskilt bevarandevärde och därför är föremål för riktade förvaltningsåtgärder. Studiens syfte var att beskriva och jämföra diet hos lax och öring i Vänern genom att undersöka vilka bytesarter som utgjorde deras föda, hur dieten skiljde sig åt i två olika delar av sjön, Dalbosjön och Värmlandssjön, samt hur parasitförekomsten i magsäckarna såg ut. I samband med sportfisketävlingar i Vänern samlades magsäckar från uppfiskad lax och öring in av sportfiskare. Maginnehållsanalys och artbestämning utfördes. Artbestämning av parasiter utfördes av Statens veterinärmedicinska anstalt genom analys av fotografi. Bytesfiskar som påträffades var nors (Osmerus eperlanus), siklöja (Coregonus albula), storspigg (Gasterosteus aculeatus aculeatus) och abborre (Perca fluviatilis). För både lax och öring var nors den vanligaste bytesfisken medan andelen siklöja var låg och storspigg var vanligt förekommande endast hos lax. Ingen signifikant skillnad noterades mellan sjöarna för lax och öring gällande den procentuella andel av magsäckarna där en viss bytesfiskart förekom. Lax i Dalbosjön hade signifikant lägre antal byten per mage än lax i Värmlandssjön. Bandmask förekom i sju procent av magarna. På en övergripande nivå verifierar resultatet i föreliggande studie i hög grad det som tidigare varit känt om dieten hos lax och öring i Vänern, samtidigt har nya rön om dieten hos dessa arter kunnat tillföras liksom kompletterande perspektiv i Vänerns ekosystembaserade fiskförvaltning. / Knowledge of fish diet is important for ecosystem-based fish management. Lake Vänern, Sweden’s largest lake, is home to populations of landlocked salmon (Salmo salar) and brown trout (Salmo trutta). These populations have special status of protection through Natura 2000 and are therefore targets for specific management efforts. The study aims to describe and compare the diet of salmon and brown trout in Lake Vänern, by finding what species of other fish they prey on and how the diet composition varies between the two lake basins Dalbosjön and Värmlandssjön, as well as the occurrence of parasites in their stomachs. The stomachs of salmon and brown trout specimen were collected by sport fishermen during sport fishing competitions in Lake Vänern. Stomach content analyses and species identification were carried out. Identification of parasite species was performed by Statens veterinärmedicinska anstalt through image analysis. Prey species consisted of European smelt (Osmerus eperlanus), vendace (Coregonus albula), three-spined stickleback (Gasterosteus aculeatus aculeatus) and European perch (Perca fluviatilis). For both salmon and brown trout, the largest proportion of prey species consisted of smelt while the proportion of vendace was low, three-spined stickleback was common only for salmon. No significant difference was found between the two basins for salmon and brown trout with regards to the proportion of stomachs where a certain prey species occurred. Salmon from Dalbosjön had significantly lower amount of prey per stomach than salmon from Värmlandssjön. Tapeworms occurred in seven percent of the sampled stomachs. The results verify previous knowledge of the diet of salmon and brown trout in Lake Vänern. New findings about the diet of these species have been added as well as complementary perspectives in Lake Vänern's ecosystem-based fish management.

Honey bees, Apis mellifera, are important pollinators across the world who provide the crucial function of maintaining the health and wellbeing of natural and agricultural ecosystems. However, in recent years, there has been a documented decline in honey bee populations worldwide. Research suggests that the intestinal microbiota of honey bees is crucial for their wellbeing and immune system as well as providing protection against harmful pathogens and affecting their growth and development. The aim of this study was to evaluate the seasonal shifts occurring within the microbiota of eight different honey bee communities and to compare the seasonal shift between autumn, winter and spring. This was done by Nanopore sequencing of the bacterial 16S rRNA gene. The results showed that there was no statistical difference between the examined species throughout this study. This is in line with current research suggesting that the intestinal microbiota of honey bees remains relatively stable. However, other studies have shown that there occur seasonal shifts in the genera within the intestines, which might suggest a larger shift occurring within the genera as opposed to the induvial species. In conclusion, no seasonal shift could be observed between the species examined throughout this study which suggests that the intestinal microbiota of honey bees remains stable throughout the year.

Apis Mellifera is the most abundant of the honeybee species thus making it one of the most crucial pollinators across the globe. It is a species that is in decline, it is important to understand these creatures in order to preserve its populations. The microbiome of these creatures is becoming an prominent area of research in understanding the lifecycle and development of these creatures and sustaining hive integrity. By investigating the nature of the microbiome in Apis melifera, it has begged the questions that brought about the aim of this research; are microbiome profiles conserved amongst the individuals of the same hive? If yes, to what extent is the microbiome profile shared between individuals? If variation between individuals of a hive do exist, what factors could influence this variation? The investigation required extracting the intestinal tract of many honey bees, extracting and purifying DNA, PCR to amplify the 16S rRNA regions of the bacteria within the tract and sequencing with the MinION (Oxford Nanopore Technologies).Readings of samples were compared and analyzed statistically to identify trends. Through this investigation it was found that species of bacteria were conserved almost entirely across bees yet abundance varied greatly. Despite this variation, there was a degree of grouping between abundances within samples. There certainly is a conservation of species in members of a hive, but the variation in reads of bacteria could be a result of caste, age, and season and requires further exploration.

No description available.

Förändrad markanvändning i form av bebyggelse, maskinkörning, jordbruk, avverkning har under en längre tid bidragit till en förlust av både biologisk mångfald och biotoper. Idag beräknas en tredjedel av jordens landyta bestå av åkermark och betesmark. En siffra som fortsatt kommer öka om konsumtion och efterfrågan går i den exponentiella takt som det idag gör. Den här studiens syfte är att undersöka om hypotesen som säger att heterogena landskap ger en högre artdiversitet stämmer. Studien ska även undersöka om det finns ett orsakssamband mellan artrikedom samt förekomst av rödlistade arter och storlek på landskap och måttet av landskap heterogenitet. Arbetet sker genom följande: litteratursökning, förarbete och avgränsning, kartarbete, hantering av data och statistisk analys. Resultat efter utförd enkel linjär regression visar att det finns ett signifikant samband mellan artdiversitet och landskapsheterogenitet, med alla 50 landskap inkluderade, men att detta kan skifta beroende på provstorlek. Resultat från samma radiestorlek (10km) men med färre antal landskap påvisar inte signifikant samband vilket är värt att notera för framtida studier inom ämnet. Studien är idag högst aktuell då ett av det största hoten idag mot biologisk mångfald är biotopförstörelse. Studien kan i framtiden utvecklas för att skapa ett bra underlag vid ställningstagande och beslut inför markförändring i det svenska landskapet. Studien hyser stora möjligheterna att utvecklas och förbättras genom mer utvecklade statistiska analyser, fler datapunkter och medräknande av fler variabler. / Changed land use in the form of buildings, machine driving, agriculture, felling has for a long time contributed to a loss of both biodiversity and biotopes. Today, it is estimated that a third of the earth's land area consists of arable land and pasture. A figure that will continue to increase if consumption and demand move at the exponential rate as it does today. The purpose of this study is to investigate whether the hypothesis that heterogeneous landscapes provide a higher species diversity is correct. The study will also examine whether there is a causal relationship between species richness and the occurrence of red-listed species and size of landscape and the measure of landscape heterogeneity. The work is done through the following: literature search, preparatory work and delimitation, map work, data handling and statistical analysis. Results after performing simple linear regression show that there is a significant relationship between species diversity and landscape heterogeneity, with all 50 landscapes included, but that this may vary depending on sample size. Results from the same radius size (10km) but with fewer landscapes do not show a significant relationship, which is worth noting for future studies in the subject. The study is today highly topical as one of the biggest threats today to biodiversity is biotope destruction. In the future, the study can be developed to create a good basis for decisions prior to land change in the Swedish landscape. The study offers great opportunities for development and improvement through more developed statistical analyzes, more data points and the inclusion of more variables.

Vättern är Europas femte största sjö och har en unik kallvattenekologi, här finns Europas viktigaste bestånd av röding (Salvelinus alpinus). Historiskt fiskades rödingen i hårt i Vättern med fångster på upp till 70 ton per år i mitten av 1900-talet, fångsten minskade sedan successivt tills den 2009 endast uppnådde 3 ton. Sedan dess har flera åtgärder för att skydda rödingen sats in så som skyddade zoner, minimimått och begränsningar för fritidsfisket. Syftet med studien är att utreda om rödingens ålders- och storleksstruktur förändrats samt om införandet av ett maximimått är en rimlig åtgärd för att skydda rödingpopulationen i Vättern.. Stora fiskhonor producerar proportionerligt fler ägg av bättre kvalitet än mindre honor, de har en längre lekperiod och deras avkommor har bättre överlevnadschans. Att skydda de stora individerna kan därför ha en positiv inverkan på hela populationen. Genom att analysera provfiskedata från åren 2005–2020 med chi2-tester och obalanserade tvåvägsanovor fanns att medelåldern ökat men att den genomsnittliga storleken och konditionen per ålder minskat något. Med hjälp av SELECT-modellen analyserades selektionen för olika grupperingar (kön och period) vilka visade att selektionen skiljer sig något mellan honor och hanar men är likvärdig över tid. Genom att jämföra olika fönsteruttag mot selektionskurvorna kan man försöka förutspå vilket uttag och maska som är bäst lämpad för rödingfiske. / Vättern is the fifth largest lake in Europe and has a unique cold-water ecology, the lake sustains Europes most valuable stock of arctic charr (Salvelinus alpinus). Back in the day  the arctic charr was heavily exploited with catches reaching over 70 tonnes on some years. Since the mid-20th century catches decreased until they reached 3 tonnes in 2009. Since  then, measures such as protected areas, minimum length requirements and limitations on recreational fishing has been taken to protect the arctic charr. The aim of this study is to decide if the age- and size structure of the arctic charr in Vättern has changed as well as  whether a maximum length requirement would be a possible measure to protect the  population of charr in Vättern. Large fich females produce proportionally more eggs of a better quality than smaller females, they have a longer spawning period and their offspring  has a higher survival rate. Protecting larger individuals could thus have a positive effect on  the entire population. By analyzing sample fishing data from the years 2005-2020 with  chi2-tests and unbalacend two-way anovas showed that the mean age int the sample had  increased while the average size per age had decreased. By using the SELECT-modell to  analyse selection we showed that selection over time is similar, but it varies between males and females. By comparing different possible harvest windows against the selection curves its possible to predict what window and mech size is most suitable.