Sök:

Sökresultat:

719 Uppsatser om Invasive alien species - Sida 2 av 48

Species diversity and geographical distribution of Fusarium species on winter wheat in two regions in Sweden

Various Fusarium species causes some of the most common cereal diseases worldwide. Besides the yield losses that can be a result of these diseases, strains from several Fusarium species can produce mycotoxins, some very toxic. The aim of this study was to investigate which Fusarium species and how many that occurred in winter wheat grains from Mälardalen and Kalmar län, if there was any difference in the distribution of Fusarium fungi between the regions and the potential within species to produce mycotoxins belonging to the group trichothecenes. Winter wheat grains collected in 2009 from ten fields (unsprayed plots) in the two regions were analysed for Fusarium species. PCR was used to amplify the TEF region where after the samples were sequenced.

KLIMATTOLERANS HOS URBANA TR?D I G?TEBORG: Analys av klimatgr?nser och framtida klimathot

Urban trees contribute significantly to our society. By providing ecosystem services and a habitat that other urban species and ecosystems depend on, both biodiversity and the people in the city benefit. Some characteristics that the trees possess include functioning as biological filters for the atmosphere and water, as well as positively impacting people's mental health. However, urban trees are challenged by stressors such as pollution and a drier environment, making them particularly sensitive to climate change. The goal of this study was to estimate the expected magnitude of climate change in Gothenburg and compare it with the current urban species' natural climate boundaries to understand the extent of the climate threat and which species appear to be most at risk.

Artrikedom av kärlväxter i övergivna och restaurerade hagmarker : betydelsen av igenväxningsgrad och tid sedan igenväxning började

Continuously grazed grasslands have remarkably high plant species diversity. In Sweden this type of habitat has declined for the last two centuries. Changed land use has caused habitat fragmentation and loss of habitat quality. This has caused a great number of plant species to end up on the verge of extinction. To try to save this unique habitat and the species that are tied to it, lots of resources are laid on restoration of abandoned grasslands. In this study, plant species richness of continuously grazed, abandoned and restored grasslands were related to degree of overgrowth, time since overgrowth started and rate of overgrowth.

Finns det något samband mellan stormusslors (unionoida) föryngring och utsläpp i närheten av dess levnadsmiljö? : en jämförelse mellan vattendrag i Västra Götaland

Common species of freshwater mussels may, like the freshwater pearl mussel (Margaritifera margaritifera) have a drastic decline in number and there is several reasons, like sedimentation, a decline of host fishes, introduction of alien species, nutrition leakages from agriculture and pollutants of medic drugs and poison. Ann Gustavsson made in the year of 2007 a study over rejuventation of freshwater great mussels in nine watersystems and considered that the rejuventation within the populations were all along the line poor. This study orients from her work and points to determine if there is a connection between the poor juventation and pollution of nitrogen and phosphorous from industries and private sanitations. The study was performed with the software program ArcGIS9.2 to take out drainage areas for the concerned habitats and contact was made with the concerned authoritys. When it comes to supervision of private sanitations is it the countys and for industries is it the county administrative board.

Klimatinducerade fenologiförändringar och dess effekter i näringsväven

The climate affects animal populations through several processes. These processes includereproduction, phenology and the success of hunting. By influencing the phenology of species theclimate also affects the way species interact. If a climate-induced phenology change promotes abasal species to bud earlier in the spring for example, this will affect the links to other species inthe food web due to a time lag in the tropic levels above. This dependence, that a predator has tobeing synchronous to its prey, is called the match/mismatch hypothesis (MMH).

Selecting plant species for the occasion of the 300th anniversary of Carl von Linné at Möckelsnäs :

This report was an outcome of a cooperation between ?The Visitor and Knowledge Project Carl von Linné? and SLU, the Swedish University of Agricultural Science. The aim with the cooperation was to create a garden and to suggest suitable plants for an orangery already built. All species suggested should have a documented relationship with Carl von Linné. The project is located in the southern part of Sweden at an estate named Möckelsnäs not far away from Linné?s birthplace.

Fjällfåglar : En jämförande studie från dal till topp i ett nordligt och sydligt svenskt fjäll

Title: Mountain birds ? a comparative study from valley to mountaintop in a northern and southern Swedish fjeld  Author: Kristian Zackrisson Abstract Main aim in this study was to increase the knowledge about birds in the Swedish mountain area. Three questions were asked: 1) Which bird species can be found during the breeding season along a low mountain slope from a forested valley to a mountaintop with bare mountain environment? 2) Do the number of species and individuals differ in different elevation zones? 3) Is the composition of bird species along a low mountain slope the same in the Kebnekaise mountains inLaplandand the Grövelsjön mountains in Dalarna? Bird census in two study sites located in the Kebnekaise mountains and the Grövelsjön mountains and subsequent analysis of the results from the bird census was the main parts in this study. Totally 20 bird species were found along a low mountain slope in the Kebnekaise mountains.

Sand pits as habitat for ground beetles (Carabidae) : does the area affect species number and composition?

Sand pits are a valuable habitat which can hold many sand living species including several endangered ones. As many sand habitats with exposed sand are declining, sand pits have a potential as a substitute habitat. This study was conducted to see what effect the area of a sand pit has on species number and composition of ground beetles (Coleoptera: Carabidae). Also, the effects of other environmental variables were tested, for example the proportion open sand, vegetation cover, sun exposure and tree cover. The study was conducted in the county of Uppsala in 2008 and included 13 sand pits with areas between 200 and 180,000 m2.

Biodiversitet av evertebrater på vegetativa tak

In a city sometimes conflicts arise between either to save the species-rich vacant lots where many species thrive, or to build new buildings. Green roofs can then serve as a refuge for plants and animals that have had their natural habitat destroyed or diminished. Today we know too little about green roofs contribution to the biodiversity in the cities. We also know very little about how various types of vegetation on roof can increase biodiversity and its ability to attract different species.The aim with this study was to examine how different types of vegetation on the roofs affect the biodiversity of the invertebrate and how species-composition and number of individuals differ between the roof- and groundlevel.This study has been carried out on Augustenborg Botanical Roof Gardens in Malmo, and in an area about 1.5 kilometers away from Augustenborg. Three different types of vegetation on the roof and ground floor were selected: sedum- ruderal and grass.

Utvärdering av Naturvårdsverkets bedömningsgrunder för makrofyter i sjöar

According to the Water Framework Directive of the European Union, macrophytes should be used as indicators in the ecological and environmental monitoring of lakes. In the member state Sweden the Environmental Protection Agency has elaborated assessment criteria for determining lake status based on macrophytes. The main focus of this thesis is to evaluate the efficiency of the assessment criteria for macrophytes. In addition the concordance between the ecological status classes of the four quality factors included was analysed.The assessment criteria for macrophytes are based on the total phosphorus preference of the respective species. The focus is thus mainly on the nutrient level of the investigated lakes and the environmental problem monitored is eutrophication.

AHA in northern Sweden ? a case study : conservation values of deciduous trees based on saproxylic insects

AHA is a Swedish abbreviation of "reveal threatened park and avenue trees" and is a method to assess the conservation value of individual trees, mainly in the park environments but also in natural stands. This method has previously only been practiced in southern Sweden (Sörensson 2008). To see if this method could provide satisfactory results in northern Sweden, I have studied it in areas around the Umeå River. This was done by studying the relationship between trees with different classifications of conservation value (as classed by the AHA method) and their content of species (species richness and abundance). Insects were collected using trunk window traps in a period of 13 weeks during the summer of 2014.

Habitat preference and dispersal of a sandassociated beetle, Apalus bimaculatus

Species that have a high degree of specialization and poor dispersal ability can be more prone to extinction than more generalist species and good dispersers. How these species traits affect the viability of populations is dependent on landscape factors,such as isolation and connectivity. Additionally, interactions between species (e.g. symbiosis), and how these interactions vary spatially and temporally can have a large impact on populations. When the range and habitat areas of a species continuously decrease, management strategies are often needed if the species shall be able to survive.

Scilla-släktets användningsmöjligheter i Sverige : med utgångspunkt i ståndort, egenskaper och historia

This study investigates the main question ?How can the small, blue spring bulb genera Chionodoxa, Puschkinia and Scilla be used in Swedish outdoor settings, with main focus on the genus Scilla?? This is done by answering four sub-questions: Which of these Scilla-species are hardy in Sweden? Which are their characteristics and habitats? What does their history of application look like? What is commercially available today? The aim of the work has been to make a survey of hardy and available Scilla-species, their character-istics, field of application and history. The purpose is to create a tool in the work with geophytes in different outdoor settings in Sweden, and to contribute to the discussion of new fields of application for bulb plants, such as Chionodoxa, Puschkinia and Scilla. The questions are answered through literature studies and discus-sions with knowledgeable persons in the field. First, an investigation and a survey of Scilla-species hardy and commercially available in Sweden, will be presented, where information of appearance, charac-teristics, habitats, varieties and historical and present application of the species will be found. With this background, a discussion around all the questions, today?s use and also new fields of application, has been carried through. The conclusions made from this study, are that there are today 15 Scilla-species commercially available and hardy for the Swedish climate.

Skydd på vilken grund? En komparativ fallstudie av den svenska utlänningslagen.

This paper studies the Swedish Alien?s Act regulations regarding individuals in need of international protection. The purpose of the essay is to examine the differences between the three grounds of protection that are found in the Swedish Alien?s Act. Central questions have been whether the origins of protection statuses granted in this act are national or international, as the UN convention relating to the status of refugees and also the progress of the European Union?s Common European Asylum System both are affecting the Swedish legislation.

Osteometriska Mätningar : För artbedömning av får, get och svin utifrån mått av revben

Ribs from sheep, goat and pig are rarely assessed  to species due to the fact that they are very similar in their morphology and size. The ribs are instead considered unidentifiable although it is possible to see what kind of bone it is. If these ribs would be identified to species not only would species assessment degree of archaeological source material   increase, the relationship between meat-rich and meat poor regions would change.To find out whether there are morphologically measurable differences between sheep, goat and pig ribs, three measurement points on each rib has been defined and measured. At each measurement point two measurements were measured, one medial-lateral measurement and one cranial-caudal measurement. The ratio between the medial- lateral measurement and the cranial-caudal measurement was calculated for each point.

<- Föregående sida 2 Nästa sida ->