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458 Uppsatser om Retention trees - Sida 19 av 31

Uttag av energisortiment vid gallring av contorta, ett komplement till konventionell gallring? :

A recommendation for stand treatment of lodgepole pine (Pinus contorta) is, in a scientific point of view, lacking when it comes to harvesting for biomass energy. Within the next decades it is expected that 280 000 hectares of lodgepole pine will have reached thinning age on the domains of Svenska Cellulosa Aktiebolaget (SCA). Due to this the interest has grown rapidly for studying the possibilities of harvesting biofuel assortments already in the first thinning. In this study the distribution of the biomass within lodgepole pine trees has been studied and taken into account for estimating the proportions of harvested assortments when using different methods of thinning. The methods studied were conventional biofuel-harvesting (with delimbed branches gathered separately from the round wood) and thinning with cutting of round wood and long tops (incl.

Restaureringens roll gällande Hornborgasjöns förmåga till kväve- och fosforretention

Idag är Hornborgasjön en av Europas viktigaste fågelsjöar men det har inte alltid varit så. Innan natur och kulturvårdsintressen värnades utdikades sjön till förmån för jordbruket och lämnades att växa igen. I början och mitten av 90-talet påbörjades och färdigställdes en omfattande restaurering av sjön som i kort innebar en höjning av vattenståndet och en ökad sjöareal. Under många år har man regelbundet testat vattenkvaliteten i Hornborgasjöns inlopp och utlopp. Rapporten syftar till att använda en del av dessa data till att undersöka sjöns retention av kväve och fosfor samt om denna förändrats i och med restaureringen. Detta gjordes med hjälp av medeldifferenserna av totalkväve och totalfosfor mellan in- och utlopp.

Har forskningen om internationella relationer någon praktisk betydelse? : En studie om idémakt i utrikespolitik

The aim of this paper is to get a deeper understanding if research about international relations has any practical meaning. The main focal point is about the importance of the scholar idea soft power, and its meaning on foreign policy actions through expressions. A quantity and quality method is used. The point of the main theory that concerns international relations takes a rationalistic perspective, and expands it to the notion that ides can have an impact on policy outcomes. Three different types of research utilization can be traced to determine in which way an idea is getting implemented.

Förändringen av tall- och granbestånden i eklandskapet söder om Linköping, 1927 jämfört med 2013

The aim of the study was to compare how the population of pine (Pinus sylvestris) and spruce (Picea abies) have changed between 1927 and 2013 in the oak landscape south of Linköping. A field study was carried out in 22 two kilometre lines which also had been studied in 1927. In these lines, which where ten meters broad and had a direction from west to east, the pines and spruces were counted, measured and classified by steam diameter. The obtained result was that the basal steam area (m²/ha) had increased for pine (44%) and spruce (57%) between 1927 and 2013. The amount of trees had increased in all diameter classes except thinner pine and spruce with a diameter of 5-10cm.

Älgens barkgnag på granstammar : omfattning med avseende på geografisk utbredning, skadad volym och ekonomiska konsekvenser

In three areas in the province of Småland studies has been done to investigate how big damage the moose may do to P. abies. An inquiry examination and two different types of surveys were done to find out how big area, which volume and which financial consequences the moose debarking has had on the forest. When the volume was calculated the rot spreading was included. The area that was damaged was stipulated with the answers from the inquiry examination. 59 % of the asked forest owners answered the inquiry.

Den sista vilan : vad kännetecknar en rofylld begravningsplats?

This essay examines the criteria for a peaceful cemetery. First there is a short history of the Swedish funeral place. After that follows the definitions of a peaceful place according to environmental psychology. From these definitions an analysis method is constructed for identifying a peaceful cemetery. The analysis method contains six criteria, shape of the entrances, existence of sound, vegetation character, the cemetery?s demarcation, the cemetery?s management and what feeling the cemetery mediates.The analysis method is put into practice on three cemeteries, Överklinten cemetery, Stockholm forest cemetery and the old cemetery in Malmö.

Lilaköttig taggsvamp, Sárcodon fuligíneovioláceus : miljökrav i Sverige och en analys av vad som styr artens etablering

Burnt Spine-cap Sárcodon fuligíneovioláceus are one the most endangered mycorrhizal fungal species in Europe. They have their main distribution in Sweden. It form mycorrhiza with pine and dependent on limestone, which makes it connected to a rare environment. It has therefore been important to study the ecology of it further and to recognise the requirement it has on the environment more accurate and what it need to establish in a new area. In this study, 31 of 34 known sites in Sweden was visited and studied in field and their history analysed through aerial photographs.

Dynamisk arbete med vegetation

Nybyggda parker och grönytor runtom i vårt land designas idag ofta utifrån ett slutgiltigt utseende. Med detta menas att en park som i slutändan förväntas domineras av tio stora ekar, planteras med tio ekar. Här finns det i stället en möjlighet att planera för förändring över tid, en långsiktig designprocess som tillåter andra uttryck att komma fram under vägen mot målbilden. Denna uppsats söker därför utforska hur vegetationsdesign och skötsel kan planeras så att de ger upplevelser kontinuerligt längs denna väg mot målbild. Tyngdvikten i denna uppsats kommer att ligga vid vegetationen under dess nyplanterade och unga år, då de fortfarande är plastiska och formbara. Naturlika planteringar, med Filborna Skogspark som exempel, kommer att undersökas.

Scintigrafisk undersökning av esofagusmotilitet hos häst :

Scintigraphic examination of the esophagus has for some time been the method of choice for the study of motility dysfunction in humans. The method has not yet been described for horses hence the lack of reference values for passage time for a bolus through the esophagus in healthy subjects. The purposes of this study were to measure passage velocity and time for a bolus to pass through the esophagus in healthy subjects, as well as to evaluate the reproducibility of the method. Eight warm-blooded trotters were used in the study. The horses were sedated with a low dose of Acepromazine prior to onset of the study.

Skötsel av tätortsnära skogliga rekreationsområden : besökares upplevelser i norra och södra Sverige

The main purpose of this M. Sc. thesis is to increase the knowledge about managing urban forestry for recreational use. The analysis is focusing on differences between visitors? experiences in the north and south of Sweden, represented by Nydalasjön and by Härlanda tjärn.

Röjningsförbandets betydelse för avverkningsekonomin i södra Sverige :

The aim of this work is to demonstrate how the net present value (NPV) at the time of the first thinning depends on the spacing after pre-commercial thinning, and show how net value from first thinning in same stand is influenced. This study is performed with models based on non-distant dependent growth models for single trees. Two different growth models have been used, one for cleaning (pre-commercial thinning) and one for thinning. The first one yields stem density distributed over diameter classes. In the second one, (the thinning model), it is possible to choose when thinning should be done, the thinning method, thinning grade and numbers of thinning.

Risk analysis and a study of risk awareness and risk communication at LEAF Gävle concerning dust explosions

The purpose of this report is to study the risk of dust explosions at the candy manufacturing plant Leaf Sverige in Gävle, Sweden. The risk analysis was conducted with a preliminary hazard analysis, PHA and event trees. The analysis focuses only on the risk posed to employees and material damages at the plant. No third person injuries have been considered. Another purpose of this report is to study risk awareness and risk communication concerning dust explosions.

Frivillig men motvillig? ? En kartläggning av faktorer som bidrar till intentioner att lämna respektive stanna i anställningen hos gruppbefäl och soldater i Försvarsmakten.

Fo?rsvarsmakten har nyligen ersatt va?rnplikten med ett personalfo?rso?rjningssystem da?r gruppbefa?l och soldater ansta?lls pa? samma villkor som pa? den civila arbetsmarknaden. En ova?ntad konsekvens av detta a?r en oo?nskat ho?g personalomsa?ttning inom denna ansta?llningskategori. Syftet med denna studie var att kartla?gga faktorer som bidrar till intentionen att stanna kvar i eller la?mna sin ansta?llning hos kategorin gruppbefa?l och soldater i Fo?rsvarsmakten.

Undersöka förbättringspotential med verktyg från Lean produktion

In the year 1783 a fissure eruption from Laki in the southern part of Iceland produced a large amount of volcanic gases during a period of eight months. The volcanic gases and aerosols spread across the northern hem sphere due to ideal weather conditions and had a substantial impact on the environment, human health and also climate effects. This, so called dry fog, caused severe health problems, which led to death casualties, killing animals, crops and other vegetation. The consequence was a widespread famine which was aggravated by a hard and long winter in 1783/84. Analysis shows that the Icelandic volcanoes are the primary risk to produce dry fog that can affect Sweden.

Where has the fertilizer gone? Closing the nutrient budget for a eucalyptus fertilization experiment in southern China

An increasing demand for wood products in China has resulted in large areas invested in fast-growing tree plantations of eucalyptus. Eucalyptus plantations are often associated with an intensive management including fertilization. By understanding the effects of fertilization and where in the ecosystem nutrients are accumulated a more sustainable forest management could be achieved. In this study, a nutrient budget including all biomass and soil components was created for Eucalyptus urophylla. The examined nutrients were nitrogen, phosphorus and potassium.

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