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719 Uppsatser om Invasive alien species - Sida 17 av 48
Könsselektering av spermier från lantbrukets husdjur
Millions of preselected progeny have been born since the development of The Beltsville Sperm Sexing Technology 1986. The method is based on flow cytometry and sorting is done on the basis of DNA difference of the X- and Y-chromosomes. Preselection of progeny provides an opportunity to obtain genetic gain and increased production as well as increased animal welfare and decreased environmental impact. However, the method is associated with low fertility, high costs and uncertainty whether the sorting process contributes to DNA damage and thereby results in genetically impaired progeny. Today, sex sorted sperm is only commercially available in the bovine industry, due to the fact that bull sperm is more suitable for selection than sperm from other species.
Svamparnas roller i svenska barrskogsekosystem : hur ser kunskapsläget ut hos några olika grupper människor?
Fungi are everywhere around us and recently, there has been
an increased interest in their role and importance in the forest.
The fungi have several strategies to acquire energy and nutrition; one example is a mutual symbiosis with trees and plants - another being dissolving organic materials.
Attempts have been made to better understand the circulation of nutrition in coniferous forests, and how fungi cooperate.
Trees and plants have adapted with mycorrhizae and are now interdependent which is important to consider in forestry.
A great number of fungi depend on dead wood and old trees to set fruiting bodies and spread further. These fungi also create environments for other species, such as birds and insects.
The vegetation of a forest is determined by a series of factors; tree species, how old the forest is, soil type, as well as the ability of the fungal spores to spread and establish. Furthermore, in determining vegetation, the fungi?s ability to compete in the soil matters. These factors are nearly unexplored.
Researching fungi knowledge and interest, a survey was distributed to five groups of people.
The groups included forest owners, high school teachers, high school students, senior citizens, and a fifth group - ?o he ? - consisting of people of mixed ages and backgrounds.
Predation på evertebrater under tidig vår i sjön Tåkern
Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.
Bildandet av naturreservat : uppföljning och klimatanpassning
AbstractWe are facing a century of rapid change in climate, with significant challenges in managing the impact of changes in living conditions for plants and animals. We can already see the responses of species through changes in phenology and spatial distribution, which may change ecosystem structure and function, with subsequent effect on ecosystem services and biological diversity. In Sweden, between 2005 and 2010, the red-listed species has increased by 13 % and similar trends can be seen across the world, making it difficult to attain national and international environmental objectives of preserving biodiversity. One way to reduce the loss of biodiversity is to protect nature from exploitation by allocating valuable areas as nature reserves, but climate change affects protected areas just as much as other landscapes and therefore requires elaborate systems of protection to facilitate species' survival. The paper has examined how the decisions and management plans for nature reserves in Sweden have been followed-up and whether they are climate adapted or not by examining 30 nature reserves, classified as newly formed (2012), recently revised (2009-2011) and older (1977-2007) reserves, and assessed what is in the decisions and management plans for follow-up, revision, long-term goals and documentation.
Vilken preferens har tjockskalig målarmussla (Unio crassus) för bottensubstrat och vattenhastighet i Storån, Östergötland?
The thick shelled river mussel (Unio crassus) has a fragmented distribution in southern Sweden. It is a threatened and protected species. In both the Swedish red list and the IUCN Red List of Threatened Species Unio crassus is classified as Endangered (EN). Causes for this classification are for instance differentiated bottom substrate and deterioration in water quality. In this study, habitat preferences of Unio crassus were investigated to assist in future restoration work.
Healthier vegetables through temperature stress? : a review of Brassica oleracea
The objective of this report is to present a review of the studies which has been carried out up to days date concerning how temperature affects vegetables physiologically when it comes to their health inducing as well as quality reducing features. The essay therefore starts off with defining what is meant by the terms health promoting and quality reducing features. It then moves on to describe how different subspecies of Brassica oleracea, that is to say vegetables such as broccoli, cauliflower, Brussels sprouts and kale, is affected by temperature. B. oleracea was chosen because the species contains several commercially interesting subspecies and therefore provides a broad field even though only one species is assessed.
Biotopskydd av stenmurar : Skäl för dispens
Stone walls in agricultural land are incorporated in the general protection of biotopes. They are protected because they provide a habitat for endangered species. Therefore it is illegal to carry out proceedings in an area that is included in the protection of biotopes. In order to do that, exemption is needed which can only be granted if there are special reasons. The essay stipulates what these special reasons are.In an exemption errand the interest for nature conservation must be weighed against a public or a private interest.
En studie av Helleborus :
This work describes the genus Helleborus both from a general point of view, and with individual descriptions of 17 species. The intention is not to make a complete description of the genus, but rather to give an overview and an introduction into the world of Helleborus. A separate chapter lists a few pests and diseases attacking the genus, followed by a brief summary of propagation methods and breeding of the genus. Finally, there is a short discussion of thoughts about the genus and its future use..
Picea mariana ((P. Mill.) B.P.S), P. abies (L.), Pinus contorta (Dougl.) och P. sylvestris (L.) : en jämförelse av produktion och potentiell kvalitet hos försöksbestånd i Jämtlands län
Swedish forests are dominated by just two conifer species Norway spruce and Scotch pine. They are not able to achieve the highest possible production or fulfill industry demands for raw materials. The introduction of exotic conifers can potentially meet these shortcomings and present a relevant solution.
This study was conducted in a block experiment with ten blocks planted in 1987 by SCA in North Sweden. The objective of the block experiment was to study if Black spruce is an appropriate alternative to Lodgepole pine, Norway spruce and Scotch pine on different site classes.
Jaummuov?rrie blomster?ng: en v?rdering av artrikedomen och dess kulturhistoriska roll
The thesis "Jaummuov?rrie Flower Meadow: An Assessment of Species Diversity and Cultural History,"
provides a detailed botanical examination of Jaummuov?rrie flower meadow in the Ammarn?s area,
focusing on its biodiversity and cultural significance. The study aims to evaluate the species richness
of the meadow and explore its role in the cultural heritage of the region. In addition to its ecological
importance, the thesis delves into the cultural history of Jaummuov?rrie flower meadow, tracing its
significance to the local community and traditional practices.
Parasitering på en expanderande art : har kartfjärilen undkommit sina naturliga fiender?
Warmer climate is a driving factor to species expansion northwards. Expansion to new areas can result in escape from natural enemies, resulting in reduced levels of mortality and thereby potentially increasing the rate of expansion. The most important parasitoid species attacking butterfly larvae belong to the families Tachinidae, Ichneumonidae and Braconidae. The aim of this thesis was to investigate parasitism and difference between populations in established area and newly colonized area for the European map butterfly, Araschnia levana, in order to examine if the butterfly has escaped from some natural enemies. In 1982 the first European map butterfly was observed in Sweden and has now established up to middle Småland.
När trädens rotsystem får bestämma : En intervjustudie med en grupp yrkesverksamma inom anläggning av hållbara gröna miljöer.
ABSTRACTThis pilot study examines the knowledge about tree root systems amongst five treeplanting professionals. The aim is to find out the professionals? collective knowledge ofthe nature of root systems of various trees used in green areas. Furthermore; to explorehow the professionals adapt landscaped green areas to the tree root properties in asustainable manner. Questions: Which tree species have special root properties toconsider and how do the professionals utilize this knowledge? And: How do theprofessionals in general adjust planting according to the root systems of trees in areas tocreate sustainable green environments?Interviews with the professionals were performed.
Finns det daglig variation i resistans i de nedre luftvägarna hos häst?
Among researchers it has been established since decades that humans and animals have an internal biological clock that controls certain physiological mechanisms. One example regarding humans is the impairment of lung function during the night, causing the phenomenon ?nocturnal asthma? among asthmatics. Only a few studies concerning respiratory circadian rhythm in horses have been done previously and they showed a daily variation in horses with a chronic or an acute respiratory disease. The technique used in those studies was the conventional technique, which is invasive and less sensitive than the technique used in this study.
Vedlevande lavar på döda grenar på levande träd i produktionsskog
Saproxylic lichens in managed forests have less substrate available than in unmanaged forests due to the shortage of dead wood. However, a suitable substrate for these lichens could be dead branches on living trees. To this date, there has not been any systematically collected data about theabundance of dead branches on living trees and the lichens growing on these branches in managed forests. The aim of this study was to see where dead branches were located on living trees of Pinus sylvestris and Picea abies, how large the surface area of these branches was and what lichens grewof wood on these branches. The study was made in Finspång, Sweden, where 11 forest stands of P.sylvestris and P.
The change of haemoglobin during blood donation, and an assessment of a photometrical method for non-invasive haemoglobin analysis
In Sweden, lowest acceptable haemoglobin levels in blood donators are 125g/L for women and 135g/L for men for a test sample taken in the beginning of the blood donation. Levels, which are 10g/L lower, are accepted if the sample is taken after the blood donation. Earlier studies show that the haemoglobin level decreases for a person that is lying down.The two aims of this study were to examine how much the haemoglobin levels change during blood donation and to examine if the photometrical instrument Pronto-7TM shows equivalent results to that of the established method Cell-Dyn Sapphire.In the study, 120 blood donors participated. Blood samples were taken in the beginning and in the end of the donation. Analyses by Pronto-7TM were done before and after the donation.The haemoglobin level decreased significantly during the blood donation.