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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Tillväxt- och åtgärdsstudie av den invasiva arten Reynoutria japonica, Parkslide / Growth and Action method Study of the Invasive Species Reynoutria Japonica, Japanese Knotweed

Holm, Josefine January 2020 (has links)
Hoten mot den biologiska mångfalden är många men kan delas in i tre huvudkategorier: biotopförstörelse, överexploatering och införsel av främmande arter. Främmande eller invasiva arter är arter som introducerats till en plats av människan och som orsakar stora problem för den inhemska biologiska mångfalden som redan existerar på platsen. Parkslide (Reynoutria japonica) är en av de arter som idag räknas som mest invasiv och skapar stora problem för den biologiska mångfalden och samhället. Parkslide har ett aggressivt rotsystem som sprider sig över stora ytor och snabbt utplånar allt som växer i anslutning till den.Syftet med studien var att i samarbete med Örnborg Kyrkander biologi & miljö AB, utarbeta åtgärdsmetoder mot Parkslide samt att studera hur stora rhizomfragment av arten behövde vara för att tillväxa. Studien delades upp i Studie A och B, där studie A undersökte rhizomfragmentens tillväxt. Studie B utförde åtgärdsförsök på Parkslide med hjälp av åtgärdsmetoderna: salt, ättika (24%) samt såpa. Resultatet för studie A visar att det finns skillnad i tillväxt mellan rhizomfragment på 1 cm och rhizomfragment på 3 cm, där 1 cm tillväxte 0% och 3 cm tillväxte 100%. Resultaten hos Studie B visade att salt var överlägsen som åtgärdsmetod och såpa minst effektiv.De resultat som studien lyckats få fram på kort tid bidrar på sikt till att en reducering av Parkslide skulle kunna vara möjlig, vilket kan vara till stor hjälp i skyddandet av de habitat som är speciellt viktiga för många arter och i slutändan för den biologiska mångfalden.
42

Mechanism specific effects of two organic pollutants in a single and co-cultured system using two cell lines from Rainbow trout

Stylin, Nicole January 2020 (has links)
The present project aims at the investigation of the toxic effects of two organic environmental compounds and to determine whether the interactions of the compounds are different in a single and co-cultured system using two cell lines. The two compounds used for this purpose were PFBS (perfluorobutanesulfonic acid) and BaP (benzo[a]pyrene). For this study, two cell lines from rainbow trout, RTgill-W1 (gills) and RTL-W1 (liver) were used to test the toxic impacts of the selected compounds. The cell lines were cultured before performing the further tests using Neutral red cytotoxicity assay, qPCR and a multiple cell system. Neutral red was used to test acute toxicity, qPCR to determine changes in the expression of selected genes, and the multiple cell system for co-culturing. The hypothesis was to establish if there where interactions between the two cell lines in co-culturing and to investigate their sensitivity towards the compounds was comparable to single cell line. Neutral red indicated that neither BaP, PFBS or mixed compounds was causing acute toxicity. However, expression in gene regulation varied between the tested concentrations of BaP and PFBS, thus; co-culture indicated on lower expression.
43

Rearing of Nile tilapia in Bio-RAS approach compared to traditionally biofloc technique.  The future of Aquaculture!

Djurstedt, Mattias January 2020 (has links)
Aquaculture is important towards the accomplishment of the Sustainable Development Goals, especially goal 14 and rural economic development in developing countries, but today aquaculture still has many unsustainable factors both in water use and organic waste. Biofloc (aggregation of microorganisms) technology is a potential aquaculture system which could make the industry more economic viable and more sustainable. In biofloc technology the reared species is together with microbes in the same water body and the toxic nitrogen species (NH4+) is converted into microbial protein. This gives both better growth performance and feed utilization, but also less water use. However, there are some problems in biofloc technology when the reared species and the microbes both has their own biological preferences towards feed, water parameters and water turbulence. These problems limit the production of the system. In Bio-RAS (term created by A. Kiessling and S. Zimmermann (RAS means Recirculating aquaculture system)) approach the water body is separate between the reared species and the microbes, therefore both organisms can be handled towards their own biological preferences. In this study Bio-RAS approach is tested and compared towards traditionally biofloc technology, where the Bio-RAS results was significant better in both growth performance and feed utilization. The conclusion is that Bio-RAS may be the future “tree branch” for the technology to follow for both economical and sustainability reasons
44

Uppföljande lavinventering runt Domsjö Fabriker / Lichen inventory around Domsjö factory

Hallgren, Erika January 2020 (has links)
The lichen population in the vicinity of Domsjö factory, Örnsköldsvik, was studied since many common species seemed to be negatively affected. The first lichen inventory in Örnsköldsvik was done in 1960 and the last one was made in 1988. A connection between the effected lichen and the sulphur dioxide emission as well as the distance from Domsjö factory was then made. The purpose of this study was to investigate if any change could be found in the population of pendoulus lichen in the vicinity of Domsjö factory, Örnsköldsvik, since the last study dating back to 1988. This study investigated the following facts; which are presence, length, and at what height on the trees the lichen Alectoria sarmentosa, Bryoria capillaris and Usnea spp. Only lichen on spruce, with trunks bigger than 150mm at breast hight were also included in the inventory. The results are based on data from 42 sites. No connection between the Domsjö factory, and the presence of Bryoria capillaris could be made, while Usnea spp. still seem to be affected. The length and the height of the investigated lichen did not seem to be affected; by the distance from Domsjö factory nor by the inventoried tree structures. No samples of Alectoria sarmentosa were found in the inventory.
45

WELL-certifiering

Hjelmar, Carolina, Sandell, Adam January 2019 (has links)
No description available.
46

Validation of Theoretical Approach to measure Biodiversity using Bird Species of a Seminatural Grassland in Sweden

Toe, Henry January 2020 (has links)
Biodiversity is a term that has recently been widely used. It is the variety and variability among living organisms and the ecological complexes in which they occur. The ongoing Worldwide biodiversity crisis comes along with a growing demand for feasible environmental indicators to measure, evaluate and communicate anthropogenic influence on biodiversity. Those indicators can be useful tools for national and regional management and support decision making processes. Therefore, LBCI (Landscape Biodiversity Capacity Index) might be a reliable method to measure biodiversity capacity, using land use data. The LBCI method is based on two indicators which are; 1. The landscape functional connectivity and 2. Landscape heterogeneity which includes number of biotopes and evenness of all these biotopes in the specified landscape. The aim of the study was to test for correlations between the BBCI (Biotope Biodiversity Capacity Index) to that of the empirical estimated biodiversity indices of bird species for semi-natural grasslands in different landscapes. The study involved the use of randomly selected fourteen landscapes of bird species, each landscape of bird species observations was downloaded from Artportalen and then two analysis were applied on the data using linear regression and non-linear fitting of Michaelis Menten function to answer the research question. The results obtained suggest that with the fourteen landscapes of bird species data, it was revealed that there was a better strong positive correlation between species richness and BBCI. Moreover, the study also suggests of confirming a positive relationship between Shannon index and BBCI respectively.
47

Blomsterlupinens olika blomfärger i relation till bebyggelse och breddgrad / The difference in flower colours of garden lupine in relation to human settlements and latitude

Ehrlander, Christine January 2020 (has links)
Blomsterlupin, Lupinus polyphyllus, är en invasiv art som introducerades i Europa som trädgårdsväxt på 1800-talet. Arten har sedan spridits och finns idag vild i stora delar av Europa. Mänskliga aktiviteter antas ha en betydande påverkan på växtens spridning. Trädgårdslupin visar en stor variation i blomfärger; där blått är den genetiskt dominerande och vanligaste färgen. I denna studie ville jag testa om avståndet till bebyggelse påverkar mångfalden i olika blomfärger och om den blå färgen blir mer dominerande, desto längre bort från bebyggelsen växtplatsen är lokaliserad. Jag undersökte också om det fanns något samband mellan mångfalden av olika blomfärger och breddgraden för växtplatsen. Det fanns inga signifikanta samband mellan de olika variablerna för vilka jag utförde regressionsanalys, men det fanns vissa trender med p-värde <0,06. Det fanns en tendens till samband mellan den ökade variationen i effektivt antal huvudfärger med latitud, vilket skulle stödja min initiala hypotes. Det fanns också en tendens att det effektiva antalet blomfärger ökade när man minskade avståndet till närmaste hus, vilket ger ett visst stöd till uppfattningen att mänskliga aktiviteter påverkar förekomsten av olika blomfärger genom multipla introduktioner. / Garden lupine, Lupinus polyphyllus, is an invasive species introduced in Europe as a garden plant in the 19th century. The species has since then spread and is today distributed over large parts of Europe. Human activities played a significant role in the spread of the plant. Garden lupine shows a large variety of flower colours, with blue being the genetically dominant and most common colour. In this study, I test whether the distance to the next settlement affects the diversity of different flower colours and if the blue colour becomes more dominant with distance from human settlements. I also investigated whether there was a relationship between the diversity of different colours and latitude. There were no significant relationships between the different variables for which I performed regression analysis, although there were some trends with p-values <0.06. There was a tendency for variation in overall flower colours to be positively correlated with latitude, which supports my initial hypothesis. There was also a tendency for effective flower colour to be inversely correlated with distance to the nearest settlement, which supports the notion that human activities affect the frequency of different flower colours through multiple introductions.
48

Comparing processed and raw honey microbiota using 16S gene barcoding

Casu Pereira de Sousa, Ricardo Antonio January 2023 (has links)
Still one of the most important animals on the planet, Honeybees are responsible for pollinating several species of plants that are vital to the ecosystem. They also produce honey, which is one of the few natural edible products of animal origin and has many beneficial properties for humans. Using 16S barcoding (SQK-16S024, Oxford Nanopore Technology) together with third generation sequencing MinION Mk1B and Flongle Flow Cell (Oxford Nanopore Technology) it was possible to acquire thousands of reads across the samples. The reads generated by the sequencer were analyzed using the Epi2Me software (Oxford Nanopore Technology) that identifies each sequence to species level. The initial results showed that the samples contained very small amounts of bacterial DNA. To increase the number of reads generated on each sample the number of cycles during PCR was increased. By Principal component analysis of the most common bacteria present across the samples, it was seen that in the microbiota of Swedish raw honey and processed honey there was no significant difference between them. When the Italian sample was considered in the analysis it was possible to see a significant difference between Swedish honey and Italian honey. The results suggest that different processes involved in preparing the honey to sell can cause differences in the microbiome of honey.
49

Lokalisering av framtida områden med värdekärnor i barrskog för tretåig hackspett och svartmes : En artjämförelse och landskapsanalys i Götene, Karlsborg och Skövde kommun / Location of future areas with value cores in coniferous forest for three-toed woodpeckers and coal tit : A species comparison and landscape analysis in the municipalities of Götene, Karlsborg and Skövde

Andersson, Carolin January 2022 (has links)
Idag sker stora populationsminskningar för många arter på grund av avsaknaden av livsmiljöer. Utifrån detta är det av stor vikt att stärka grön infrastruktur i hela landskapet och speciellt i sådana områden där det idag finns brist på livsmiljöer för olika djur- och växtarter. Värdekärna är den primära indikatorn för att beskriva kvalitéer i landskapet och kan till exempel utgöras av en nyckelbiotop i skogen. Den tretåiga hackspetten (Picoides tridactylus) anses i allmänt vara en specialist på barrskog och även svartmesen (Periparus ater) betraktas som en utpräglad barrskogsart. Syftet med studien är att undersöka om det finns områden i Götene, Karlsborg och Skövde kommun som kan utöka/förbättra barrskogsområden med värdekärnor. Detta genom att utföra en landskapsanalys och jämföra levnadsförutsättningarna mellan de två barrskogsarterna, tretåig hackspett (Picoides tridactylus) och svartmes (Periparus ater). Målet är att på lång sikt försöka förbättra områden med värdekärnor i berörda kommuner för att öka arternas förekomst och sannolikheten att överleva. Data för värdekärnor, avverkningsanmälningar och medelhöjd av träd har analyserats i ArcMap för eventuella hot mot arternas livsmiljö och lokalisering av potentiella framtida livsmiljö områden. Karlsborg kommun har stört areal av värdekärnor och minst avverkningsanmälning. Skövde kommun har mindre areal av värdekärnor och mer avverkningsanmälningar jämfört med Karlsborg. Götene kommun har minst areal av värdekärnor och mest avverkningsanmälningar. Skövde kommun har störts areal av potentiella framtida områden med värdekärnor för båda arterna. Karlsborg kommun har något mindre än Skövde och Götene kommun har mints areal av potentiella framtida områden med värdekärnor för båda arterna. Resultaten framtagna i denna studie kan inte betraktas som mer än ett första steg i arbetet med att försöka lokalisera framtida områden med värdekärnor för den tretåiga hackspetten och svartmesen. För framtida arbeten skulle det vara av intresse att i fält inventera de ”potentiellt framtida områdena” och på så vis avgöra om denna arbetsmetod är något som går att tillämpa i fler kommuner och eventuellt andra fågelarter för att finna potentiella framtida områden med värdekärnor för arter. / Today, large population reductions occur for many species due to the lack of habitats. Based on this, it is of great importance to strengthen green infrastructure throughout the landscape and especially in such areas where there is currently a shortage of habitats for various animal and plant species. Value core is the primary indicator for describing qualities in the landscape and can, for example, consist of a key biotope in the forest. The three-toed woodpecker (Picoides tridactylus) is generally considered a specialist in coniferous forest and the black tit (Periparus ater) is also considered a distinct coniferous forest species. The purpose of the study is to investigate whether there are areas in Götene, Karlsborg and Skövde municipalities that can expand / improve coniferous forest areas with core values. This is done by performing a landscape analysis and comparing the living conditions between the two coniferous forest species, the threetoed woodpecker (Picoides tridactylus) and the black tit (Periparus ater). The goal is to try to improve areas with core values in the municipalities concerned in the long term in order to increase the occurrence of the species and the probability of survival. Data for core values, deforestation reports and average height of trees have been analyzed in ArcMap for possible threats to the species' habitat and location of potential future habitat areas. Karlsborg municipality has disturbed the area of value cores and at least felling reports. Skövde municipality has a smaller area of value cores and more felling reports compared to Karlsborg. Götene municipality has the least area of value cores and the most felling reports. Skövde municipality has disturbed area of potential future areas with core values for both species. Karlsborg municipality has slightly less than Skövde and Götene municipality has mined area of potential future areas with value cores for both species. The results of this study cannot be considered as more than a first step in the work of trying to locate future areas with value cores for the threetoed woodpecker and the black tit. For future work, it would be of interest to inventory the "potentially future areas" in the field and thus determine whether this working method is something that can be applied in more municipalities and possibly other bird species to find potential future areas with value cores for species.
50

FRÅN UTSÄTTNING AV ÖRINGROM TILL ÅRSYNGEL : EFFEKTER AV UTSÄTTNINGSMETODIK OCH INTRASPECIFIKA INTERAKTIONER

Rode, David January 2023 (has links)
Egg stocking is a common method of re-establishing brown trout (Salmo trutta) populations, while the outcomes have been shown to give different results depending on variations in methods and locations. More recently, the dispersal of yearlings has been studied, but research on intraspecific interactions after egg stocking and the optimal number of eggs stocked are less studied. The aim of this study was to increase the understanding of stocking of egg methodology and how competition from older trout affect the resulting density of yearling trout. This was done to contribute to an optimization of growth and survival of trout from egg stockings. The study was based on data on egg stocking numbers and density estimates of young trout from electrofishing surveys in Rotälven, a tributary to Österdalälven, Dalarna County. Egg stocking has taken place from 2018 and onwards with a continuous increase in numbers from 84,000 to 1.35 million eggs per year. Here I studied eleven approximately 1000 m stream sections that had been sampled for surviving yearlings of trout from egg stockings in each section located in the main channel of Rotälven. There was a difference in the density of yearlings on the side of the river where the egg was stocked compared to the opposite side. On the other hand, there was no difference in the density of yearlings in the section where 100,000 eggs were stocked compared to the section where 50 000 were stocked. Furthermore, there was no correlation between the density of yearlings and older fish density in the study sections or in different stream velocities. Furthermore, was there neither any correlation between average length of yearlings nor densities of different ages of trout. These findings could contribute to an optimized stocking of egg through increased understanding of competition between year classes and stocking of egg methodology.

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