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912 Uppsatser om Tree species - Sida 18 av 61

Matematisk generering och realtidsrendering av vegetation i Gizmo3D

To render outdoor scenes with lots of vegetation in real time is a big challenge. This problem has important applications in the areas of visualization and simulation. Some progress has been made the last years, but a previously unsolved difficulty has been to combine high rendering quality with abundant variation in scenes. I present a method to mathematically generate and render vegetation in real time, with implementation in the scene graph Gizmo3D. The most important quality of the method is its ability to render scenes with many unique specimens with very low aliasing.

Inokulering med två hjorttryfflar på arginingödslade täckrotsplantor i Gideå plantskola :

The effect of inoculation on containerized pine and spruce seedlings in a nursery with two ectomycorrhizal fungi was investigated in regard to the development of mycorrhiza and plant growth. The fungi were Elaphomyces muricatus and Elaphomyces granulates and the inoculated seedlings were compared to an uninoculated control. These seedlings were all fertilized with arginine. Five mycorrhiza species were found after DNA sequencing of the mycorrhizal root tips with different found morphotypes on seedlings from all treatments. Thelephora terrestris was the type which had the greatest distribution on pine seedlings and Tylospora asterophora was found at big extent on spruce seedlings. The inoculated species was not found, if it was due to the species hadn?t colonized the roots or if the DNA sequencing failed we can only speculate about.

Produktivitet vid stubbskörd :

Stump harvest could be found in the late 1970?s and the early 1980?s. And now when the prices on energy are high it has become an interesting topic again. This work has been conducted within Holmen Skog?s stump harvest testing in Norrköping.

Influence of prescribed burning and/or mechanical site preparation on stand stem density and growth of Scots pine stands above the Arctic Circle : results 9-19 years after stand establishment

Prescribed burning was commonly used for site preparation in Sweden to establish new forests until the 1960?s, when mechanical scarification was introduced. During recent decades the interest in prescribed burnings has increased again, mainly due to certifications of forestry stating that 5% of the regeneration areas should be burned on dry and mesic soils. The objective of the study was to evaluate actual influence of prescribed burning compared to other site preparation on stand stem density, growth parameters and tree damages for Scots pine (Pinus sylvestris L.) after direct seeding and planting. The study also attempts to simulate growth until first thinning.

Spaljerad frukt på Trädgårdens skola. Rapport från ett praktiskt trädgårdsmästararbete

Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Trädgårdens hantverk och design, 21 hp, 2010.

Två år efter restaurering:Vad har förändrats i bottenfaunan?

The aim of the study was to examine if the benthos in a restored portion of a small lowland stream south of Linkoping differed from two non restored reference areas two years after restoration. The reference areas were one stretch downstream and one upstream stretches of the restored stream. The benthic invertebrates were collected using standardized kick sampling. In order to classify the communities and estimate any differences, three different indices were exercised. In addition rank-abundance curves and checklists were used to get a picture of species composition.

Torrefaction of biomass : a comparative and kinetic study of thermal decomposition for Norway spruce stump, poplar and fuel tree chips

Stump biomass is energy rich and stump harvesting for use as fuel become more and more interesting in Sweden. Swedish Forest Agency (2009) has estimated that stump harvesting in Sweden would respond to an annual energy supply of 57 TWh/year. However, stump has not been recognized as a bioenergy resource in Sweden. Suitable methods for pre-treatment of stump are probably of great importance to make it accepted as fuel. It is therefore rewarding to carry out an investigation in this area for stump. This report represents results from a diploma project, which was aimed to develop a fixed bed reactor for experimental study of biomass torrefaction, followed by TG analysis and kinetic modelling employing Ozawa method and different kinetic models including one-step and three-pseudo-component models.

Nyttan av kurserna på naturbruksprogrammets djurvårdsinriktning

The aim of this study is to find out if the former students think that they have made use of the courses they have taken at the Natural Resource Use Programme specialised in Animal Husbandry at Lillerudsgymnasiet or if the courses should be exchanged. In the study it is assumed that a course can be useful professionally, for further studies and in private life.The main questions are: Have the former students made use of the courses they took at the Natural Resource Use Programme specialised in Animal Husbandry at Lillerudsgymnasiet? Was it the right decision to replace the course Horses?I have sent a questionnaire to all the students who graduated between 2003 and 2007. Out of 107 questionnaires I received 66 replies (62 %). All students have studied the same mandatory courses but different eligible courses.

Epixylic lichens and bryophytes in young managed forests : substrate preferences and amounts of dead wood

Dead wood is important for many species. The amount of coarse dead wood (diameter >10 cm) is much lower in managed forest than in unmanaged forests. Stumps constitute the largest proportion of the volume of coarse dead wood in managed forests. Since stump harvest for biofuel may increase, the amount of dead wood will decrease even more, which may threaten biodiversity. The first aim of this study was to compare the amounts of fine woody debris (FWD, .

The welfare of bottlenose dolphins and killer whales in captivity

The aim of this paper was to investigate whether or not it is possible to keep bottlenose dolphins and killer whales in captivity while maintaining good animal welfare. Today, many zoos and aquariums claim that their primary function is to conserve species and educate people about conservation and threatened species. The keeping of wild animals is justified by conservation programs and by the information spread to the zoo visitors. This does however not seem to be the case for marine mammals such as bottlenose dolphins (Tursiops sp.) and killer whales (Oricnus orca) since these species are not threatened in the wild and neither of them are listed as threatened in IUCN's Red List. Bottlenose dolphins and killer whales are entirely aquatic carnivores and are distributed in all coastal and pelagic waters from the Arctic ice in the north to the Antarctic ice in the south.

Ståndortsanpassning och produktionspotential för björk i Gävleborgs län

Large amounts of birch-timber are imported to Sweden, from particularly the Baltic States, since the domestic production can?t support the pulp industry. The goal of this study was to show the potential of birch and the area?s most suitable for birch production. The study was limited to Gävleborg County. Using site characteristics, site index (SI) for birch was estimated on all National Forest Inventory plots in Gävleborg County.

Do 25 years old skid tracks restrict growth and survival? : a study on growth conditions for the planted regeneration in a rainforest rehabilitation project

The rainforests of the world are important not only to the countries in which they grow but to the world as a whole. They influence oxygen and water circulation as well as carbon sequestration which in turn affect global radiation and global warming. The forest also have great value and in Malaysia as in many other tropical countries large volumes are harvested which leaves great areas of degraded forest with little growth and biological diversity. Due to their low financial value these forests are often transformed and used for other purposes than forestry such as oil palm plantations. The trees are often transported out of the forest using large bulldozers. They are heavy which causes compaction of the forest floor and during transport the top soil layers are moved to improve mobility.

DYNAMIKEN OCH EFFEKTEN AV MARINA V?RMEB?LJOR P? TROPISKA KORALLER (SCLERACTINIA)

Marine heatwaves (MHW) have become increasingly common in recent decades due to greenhouse gas emissions that have caused climate change. A marine heatwave is when the sea surface temperature rises, which damage many different ecosystems in the sea. One ecosystem that is sensitive to temperature changes is tropical coral reefs, which are at risk of bleaching during marine heatwaves. Coral bleaching is when its symbionts leave the coral and they lose their color, while also starving to death as they lose their food source. The purpose of this report was therefore to investigate what the connection between marine heatwaves and coral bleaching looks like, and to see if there are any geographical differences.

Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län

During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams.The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net called strömöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets.

Orienterare, framtidens naturvårdare? : Inventering av markstörningar i samband med O-Ringen i Skåne 2014

As an increasingly rationalized forestry and agriculture have human interference in the form of tradition, grazing and use declined. There is a strong link between biodiversity and disturbance of the landscape. In sandy soils many insects and plants require exposed sand to survive while the disorder may contribute to seed dispersal in the woodlands. On behalf of O-Ringen Skåne 2014, a study of the interference from orienteering in sandy soil and the forest during competitions conducted. The aim is to clarify the interference of which orienteering runners contributes, through to inventory presence before and after the competitions in the bottom and field layer in three locations.

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