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912 Uppsatser om Tree species - Sida 25 av 61

Analys av linjetaxering i samband med gallringsinventering med avseende på kvalitet, tillförlitlighet och framtida utformning

Modern forest owners are very familiar with forest management and forest economics. Therefore they have high demands for quality in forest operations. Guarantee of quality in the shape of self-checking activities is an important tool to guarantee a well managed forestry operation. To meet the forest owners? demands on guarantee of quality and the entrepreneurs wish of an easy method for self-checking, the forest owners association, Södra skogsägarna, has developed a new method for thinning inventory. The purpose of this study is to evaluate the method that is used for self-checking and to find ways to develop and improve of the method. The data has been collected by inventory in a number of stands with circle-area survey and with strip survey, which is method that is used for self-checking. The results show that the strip survey does not diverge more than ±10 % in measuring values of basal area, number of stems, roads share, thinning quotient, outtake of basal area and total volume compared to circle-area survey.

Analys av hemområdesstorlek hos mellansvenska vildsvin (Sus scrofa scrofa)

The wild boar population grows rapidly in number in Sweden, and it has been predicted that the annual number of shot wild boar will soon exceed the cull of moose. According to estimates, the Swedish population encompassed some 150 000 individuals in 2010. The mean annual harvest has increased by 30% since 1990, indicating that the wild boar is a species we must learn to manage sustainably. A successful management of the boars aims for a population in balance with agriculture and traffic, and also provides good hunting opportunities. For this to be possible, understandings of several aspects of the ecology of wild boar is needed. The sows in this study had an average homerange of 707 hectares during summer, and 659 hectares in winter.

Parametriserad 3D-modell av cyklon : Parametrisering av en 3D-modell av ett cyklonfilter i SolidWorks för snabb framtagning av nya konstruktioner till Outotec Skellefteå

This bachelor thesis project has been executed at Outotec Sweden AB in Skellefteå. Outotecs main business focus is selling mineral and metal processing technologies. A rest product from the metal process is particle-polluted gas and cyclone designs are today the most commonly used abatement device for particle control. A cyclone provides a simple design with high efficiency particle percolation by using air streams.The purpose of this work is to reduce the time it takes create new cyclone designs in Outotecs projects. An extensive construction work is needed for every new cyclone order due to new designs.

Skyddet av arter: en jämförelse mellan amerikanska Endangered Species Act och den svenska fridlysningslagstiftningen

I dagens samhälle är skyddet av hotade och utrotningshotade arter väldigt aktuellt och kontroversiellt. Den problematik som uppstår när man vill skydda arter återfinns i alla länder, därför är det intressant att se hur andra länder valt att genomföra sitt skydd. Ett land med en omtalad och långtgående lagstiftning i detta fall är USA. Därför valde jag att genomföra en jämförelse mellan USA:s Endagered Species Act (ESA) och den Svenska fridlysningslagstiftningen. Den svenska fridlysningslagstiftningen är ingen enhetlig lagstiftning såtillvida att den har samlats upp enbart i miljöbalken (MB).

Rosenlunds bankar : Erosion och förändring sedan 1960

During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught.The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase.

Föryngringsplan för en svårt stormskadad fastighet i Kronobergs län :

In January 2005 large forest areas in south Sweden were severely damaged by storm. This final thesis describes the work with creating an ecological and landscape-adapted regeneration plan for a severely storm damaged property in Kronobergs region in south Sweden. This regeneration plan, in difference to more regular plans, are focusing more on the owner?s use and goal?s for the property and seeing the property from a more comprehensive view in the regeneration process. Beside production and environmental values the plan also take in consideration other values as aesthetic, culture history, landscape picture and recreation values.

Evaluating six crop mixes used for game fields in southwest Sweden : biomass production, fallow deer preference and species diversity

Game fields are one way to divert animals away from sensitive areas, create shelter and forage, and also to increase the biological diversity. In this study I investigated how the plant composition in six different crop mixes used for game fields affected the biomass production, biomass consumption and biological diversity at the Koberg estate in southwestern Sweden. Six experimental fields were used and each field contained six plots, approximately 1500 m2 each, that was sown with a different crop mix. The crop mixes ranged from a pure grass mix (A), 70 % grass and 30 % leguminous plants (B), 53 % grass, 21 % leguminous plants and 26 % other herbs (C), 100 % leguminous plants (D) to the most complex mixes constituting of 91 % leguminous plants and 9 % other herbs (E) and 87 % leguminous plants and 13 % other herbs (F). The fields were cut weekly during the summer in 2010, to estimate weekly biomass production.

Hur påverkas dvärghamstrar av att vistas i hamsterbollar?

Lately the popularity to keep different species of dwarf hamsters has increased in Sweden. The requirements of the Swedish legislation to keep hamsters as pets are low which could be a reason for the increasing popularity. Hamsters are in nature generally nocturnal and can travel far distances to find food sources during their active part of the day. Their eyesight is poor, but is compensated by their well-developed hearing and olfaction. ?Run about balls? are made of plastic and the hamster is placed inside it where after the ball is placed on the floor and the hamster can then run protected outside the cage.

Ekosystemstödjande och multifunktionella växtval i urban miljö : En fallstudie med utgångspunkt i Nacka stadsbildning

This study has investigated how urban vegetation can be used in a multifunctional way to support ecosystem services in urban environments. Nacka municipality is in the start-up phase of building what is to become Nacka city. This provides a unique possibility to study and analyse what role the vegetation play in making the city a healthy living environment and how it needs to be adapted in order to be resilient against changing climate conditions and how the effects of those changes can be regulated. The study further investigates how airborne pollution, caused by urbanization processes, can be regulated or reduced by vegetation or species selection. Methods used in this study were a combination of qualitative interviews and literature studies, seeking to answer the questions: Which specific ecosystem functions are needed in the urban environment and which aspects will influence the ecosystems ability to deliver the functions in demand? And which plant species have the right mechanisms needed to deliver those functions? These questions have been studied and analysed in a local based context where the local conditions ands site specific needs of Nacka define criteria for plant selection.

Uptake of 137Cs by fungi and plants due to potassiumfertilization in Heby municipality in response to theChernobyl nuclear accident

The fallout from the Chernobyl nuclear accident resulted in large deposits of caesium, iodineand strontium as well as noble gases in various parts of Sweden. 137Cs has a radioactive halflifeof about 30 years and is therefore one of few radio-fission products remaining inmeasurable quantities in the Swedish soil. Radiocaesium behaves similarly to potassium insoil-plant systems and is easily absorbed by plants. It is important to understand how 137Csbehaves in different ecosystems in order to minimize the risk toward humans.The aim of this study was to determine how potassium fertilization influences radiocaesiumcontent in different forest plants and fungi. Potassium fertilizer was spread once in 1992 withapproximately 200 kg KCl per ha.

Födosammansättning hos gråsäl (Halichoerus grypus) samt test av flotte för insamling av sälfekalier.

During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught.The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase.

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.

Leaf area index in Vittelaria Paradoxa parklands in Burkina Faso estimated by light interception and leaf sampling

Burkina Faso as well as most sub-Saharan African countries struggle with providing food for a fast growing population. The dominating farming system is agroforestry parklands. Agroforestry parklands can broadly be defined as areas where scattered trees occur on farmlands as a result of selective clearing. The presence of trees in crop fields may in the long term have a positive effect on the production of annual crops. It is commonly discussed, but not proven, that the presence of trees leads to increased groundwater recharge due to higher infiltration capacity of the soil.

Hur kopplad är asp till tidigare jordbruksmark? : en studie av aspförekomst och tidigare markanvändning i fem län i Mellansverige

Aspen (Populus tremula) is a tree that is important for biodiversity. It is a pioneer tree that is favored by much light. It is possible that aspens that regenerated on agricultural land have a different importance for biodiversity than aspens that regenerated in forests, since their conditions have been different. By studying how the land use have changed you can see how many of today?s aspens regeneretad on agricultural land.

Lactobacilli in the gastrointestinal tract of dog and wolf : isolation, identification and characterization of L. reuteri

Since the first wolf was taken as a companion animal a lot have happened with the biology of these animals. Is it possible that changes in the gut microbiota of the domestic dog are involved in the increasing numbers of animals with gastrointestinal disorders? Probiotics have been proven to promote the immune system of dogs by increasing concentrations of neutrophils and monocytes, decreasing the fragility of erythrocytes and increasing the serum IgG concentrations. Probiotics have also been shown to improve the fecal consistency, fecal dry matter and defecation frequency of dogs. The aim of this study was to find out if the bacterial counts in the gut of dogs differed from the gut of wolves, with the focus on lactobacilli.

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