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2121 Uppsatser om Clear-cutting - Sida 1 av 142

Hur påverkas bentiska funktionella födogrupper av kalavverkning? : Effekt på abundans, samt återhämning, av funktionella födogrupper efter kalavverkning kring små vattendrag.

Forestry affects most of the forest-covered land in Sweden. In the landscape, the most common stream type is headwaters, which are important sites for many processes and organisms in both the terrestrial and the aquatic ecosystems. The aim of this study was to investigate how the abundance of benthic invertebrate functional feeding groups in headwater streams develops after Clear-cutting and if it also is possible to detect a change in the composition of feeding groups. The study also attempts to determine what factors have an effect on temporal changes in abundance of these groups. For the study, 11 sites in northern Sweden were sampled for benthic invertebrates using a Surber-sampler, and for each site canopy-cover and pH was obtained.

Hur stor areal äldre skog lämplig för trakthyggesbruk finns det på Gotland 2013?

The degree project at hand investigates how large areas of older forest (80 plus years) suitable for clear cutting there is on the Swedish island of Gotland. Large areas of older forest on Gotland are situated on land with shallow soil depths which are economically uninteresting and often unsuitable for clear cutting forestry. Other forests hold big nature conservation values and should not, or cannot, be used for forestry purposes. The survey is made as a GIS analysis based on the old but carefully made ?Brief forest inventory? (ÖSI) made in the 1980s and early 1990s. A sample from the inventory is combined with studies of orthophotos, satellite photos and other GIS layers that display estimated soil depth and nature conservation values. Partly contrary to common belief, the survey shows that there are still large areas of older forest suitable for clear cutting forestry on the island.

Laserskärning i Sverige : ? tekniken, marknaden och hur de utvecklas

Laser for material processing possesses a number of advantages which mean that it has been and will be an important component for a wide range of industries' future development. Cutting materials processing is the dominant use of laser technology and has revolutionized the manufacturing industry. The aim of this thesis is to describe the principles of metal cutting by laser, how laser cutting is applied in practice and to identify how Swedish companies are using laser cutting. For the theoretical and technical description of laser cutting literature studies are the primary source of information. The empirical basis for the mapping of the Swedish industry for laser cutting is grounded on a survey; this includes Swedish companies that use laser cutting in their production.

Skogsmarksgödsling : en ekonomisk analys av olika gödslingsstrategier för ett skogsinnehav i norra Sverige

The purpose of this study is to analyze the economic effects of different fertilization programs both on stand- and forest-level. The study is applied on an objective sample of inventory data for a forest area in Kalix in northern Sweden. The forest area belongs to the forest company Sveaskog. The study includes different economic models and will be used as a support when the company decides how to invest and how much to invest in fertilization. The study investigates the economy of five different fertilization policies. For each program the rate of interest invested in fertilization and the cost for the extra produced volume has been calculated.

Clear-cut and substrate characteristics important for the occurrence of the beetle Upis ceramboides

Disturbances, such as fire and wind, are important for saproxylic beetles (= beetles depending on decaying wood) to gain substrate in boreal forests. Clear-cutting is an example of a man-made disturbance. Measures such as prescribed burning have been made to resemble natural disturbances. The aim of this study was to see which clear-cut characteristics are important for the occurrence of the saproxylic beetle Upis ceramboides. This is a species favored by open habitats and is said to respond positively to forest fires. The distribution area in Sweden for this species has decreased during the last two centuries and I wanted to see if there were differences between clear-cuts in Hälsingland, where it is very rare and decreasing, and Norrbotten where this study was conducted.

Bakteriell produktion i humösa istäckta sjöar i norra Sverige

The main purposes of this study were to 1) quantify bacterial production in winter during ice conditions, and 2) to compare these production measures with values measured from summer and open water conditions in three humic lakes situated in northern Sweden. Another purpose of this study was to 3) examine whether Clear-cutting significantly affected bacterial production or water chemistry in two lakes situated in catchments were a large part of the forest had been removed through logging compared to an undisturbed reference lake. In winter (March/April 2014), the bacterial production ranged from 0, 7 - 2, 2 µgC/L/day and in the summer of 2013 the production values was 4 ? 10 times higher. The main reason for lower bacterial production in winter was ascribed to lower water temperatures as well as to older and more recalcitrant DOC, as there were no significant differences in total dissolved nitrogen or DOC concentration or -quality, that could explain a lower production compared to summer.

Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet

Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).

Maskinduglighet på planlaserskärare

Lars Höglund AB is one of Scandinavia?s most qualified manufacturers of sheet metal products and provides custom designed products of very detailed precision. One of the main methods of manufacturing is laser cutting. When Lars Höglund AB signed up a new customer, with high demands in tolerances for the products, Lars Höglund AB thought it would be necessary to know the capability of the laser cutting machine. Also the process of how to retrieve this capability was interesting. The capability will be researched for the following elements: Cutting right angles in squares with a corner radius of 1 mmCutting corners which are not right angleCutting of circles with constant radius Measurements were made on 150 pieces of sheet metal details, which had been cut out by the machine.  The data from the measurements where later used to study the capability.

Kartläggning av spånprodukter vid Sävar såg

A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning.

Ökad kollagring i boreal skog : Kan blädningsbrukad skog lagra mer kol än trakthyggesbrukad skog?

This study was conducted to test the hypotheses that a forest managed by selective cutting can store more carbon than a forest managed by clearcutting. The study was carried out as a meta-analysis. The data that was found was analyzed by performing t-tests on the proportional effect that the two silvicultural methods had on the driving factors of CO2-efflux and carbon stores in coniferous boreal forest. In all areas tested, an effect in favor of selective cutting was found, but not all of them significant however. The soil respiration following selective cutting was significantly lower than that of clearcutting, and the primary production of a clearcut area cannot according to reason exceed that of an area post-selective cutting.

Hänsyn till mark och vatten vid slutavverkning : en fältstudie på känsliga marker

The purpose of this study is to investigate if there is enough consideration taken to sensitive forest areas close to water or wetlands during clear cutting assignments, and to estimate the extent of damage made by forestry machines used at that time. A field and literature study is used to show how to improve and prevent the damage made in the wake of the machines. This study is made for Sydved, and shall culminate in a policy to prevent ground damage during their clear cutting assignments. The areas which were part of the field studies were clearcuttings on fine grained soil close to water and wetlands. The purpose was to find out if the water had been affected, what had been done to prevent ground damages and what more could have been done. The results of the field studies show that more work needs to be done to reach up to expectations. More information about the assignment area, better planning of sensitive regions, and strengthening of the main haul roads with brush are some of the improvements that can be done. There is also a need for more exact guidelines, follow-ups and education for everyone involved to have the same goals and understanding to prevent ground damage..

Objektskoncentration vid slutavverkning

The study is made on behalf of SCA Skog Jämtlands förvaltning which is one of five administration units that SCA Skog consists of. The purpose of the study is to investigate which reduced expenses there are according to spatial concentration of cutting areas. By increasing the spatial concentration of cutting areas it will reduce the need of movements by trailer, also reduce the number of roads that you use during the activities. To be able to perform the study, access to a annual cuttings in nine years have been made available. From this volume new annual cuttings has been created but more concentrated. The two different results have been compared and the results show that concentration of cutting areas generates reduced need for trailer transports and less km road that has to be maintained. But then, if it´s practical viable can be discussed.

Kvickrotens reaktion på klippning och konkurrens i rajgräs- och vitklöverbestånd :

Couch grass (Elymus repens (L.) Gould) is a severe weed in Sweden, and since both the use of herbicides and cultivation should be decreased, it will become increasingly problematic to control couch. The present work is meant to, by literature studies and an experiment, give some answers to the question if cutting and competition can depress the growth of couch. The experiment was carried out in the growing season 2001 at Ultuna, Uppsala, in plastic boxes. The design was three-factorial randomised complete blocks. The factors were plant combination, nitrogen level and cutting strategy.

Dragbrotschning av invändiga profiler

High-precision cutting in metal is very complicated, a lot of parameters affect the result: what geometries to be manufactured, surface roughness and tolerances to be achieved, batch size etcetera. When pull-broaching internal parts this might be even more important, than in any other cutting operation. Everything is machined in one single stroke and the general technology is built in to the tool, therefore big investments must be made to change the process. Milling for an example: one piece at a time is machined away, and a lot of parameters can be changed easily.It is very high pressure on the cutting-edge when the broach is cutting. To achieve the specified product and to avoid unnecessary toolwear it is essential to use the right cuttingfluid and the right cuttingspeed for an example.

Hur man förstör en film : Svenska Statens Biografbyrås censur av Hellraiser

The Swedish censorship is an institution run by the Swedish government since 1911 and has cutting films to protect the citizens from unnecessary violence. Their main purpose doesn't work well with the law of copyright in literary and artistic works, as they break this law while cutting movies. They therefore destroy the authors work by doing this, and in this thesis I will point out how they have destroyed the purpose of two scenes in the film Hellraiser and by that, more or less, altered how the audience may look upon two of the characters in the film.  The results points to the unnecessary way of physically cutting films to protect the audience, but also how they choose to work and what preferences they used in their line of work..

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