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117 Uppsatser om Harvesting - Sida 1 av 8
Simulation of rattan harvests in Indonesia : different harvesting pressures and the resulting patterns
The objectives of this research were to determine whether the natural rattan resources in Sulawesi, Indonesia can cope with the strongly increased Harvesting pressure that has occurred over the last centuries. I was furthermore looking for patterns in the rattan population dynamics that might give a hint on how the Harvesting system could be improved to ensure a maximum sustainable yield. To
answer these questions, I developed an individual-based model to analyse the dynamics of rattan growth in connection with rattan harvests by locals to identify sustainable levels of rattan harvests around villages in Sulawesi, Indonesia. Scenarios with different Harvesting intensities were run to compare the change in harvest amount. For a given Harvesting pressure, scenarios with a high number of harvesters and a low Harvesting frequency had the same effect as scenarios with high Harvesting frequencies and a low number of harvesters.
Detektor på skördare för utsortering av träd med metallskrot
Fortifikationsverket which is the landlord for the Swedish national defence has a great problem in their forestry due to the relatively large amount of metal objects in their timber. These metal objects cause different types of economical losses in the timber refinement chain. To enable out sorting of logs containing metal objects already in the Harvesting phase, Fortifikationsverket is interested of the possibility to utilize some type of metal detector in a Harvesting head for that purpose.The goal of this study was to, with help of a case study, enlighten the problem that metal objects in timber cause for Fortifikationsverket and their customers of timber and to investigate conditions of to mount and utilize some kind of metal detector in a Harvesting head at present.The saw timber deliveries by Fortifikationsverket during the time period 2003-2005 was used as a reference volume for calculations of economical losses. In this case study was included two sawmills where timber from Fortifikationsverket were delivered to for further refinement. Factors investigated were the type of damage metal objects caused in these two sawmills and the economical signification of these damages.
GPS- & GIS-användning i drivningsprocessen hos Stora Enso SKog AB :
GPS (Global Positioning system) and GIS (Geographical information system) has been used for planning and inventory in the forest sector for more than ten years. The last years the development has come to equip harvesters and forwarders with GPS and GIS (GIT).
The goal with this study was to reach a basis for decision, how Stora Enso Skog should continue its investment in GPS and GIS in harvesters and forwarders. To reach this basis for decision, possible advantages and benefits, disadvantages and problems in the Harvesting process was evaluated. The study was made as an interview study with four Harvesting managers and ten machine teams. To secure the quality of the results an interview questionnaire was made before the interviews were done.
The results showed that GIT will make the Harvesting managers work easier.
Bättre åtkomst till avverkningstrakter med anpassat marktryck från avverkningsmaskinerna
The global climate-change means increasing mean-temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the Harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the Harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when Harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged Harvesting grounds was made.
Gödslingsstrategins inverkan på Holmen Skog, Umeå distrikt
This thesis analyzes the effects of different fertilization strategies on forest management at Holmen Skog in Umeå district. Harvesting volumes, net present values and fertilization intensity are presented for each fertilization scenario. The planning reserve (percentage area older than minimum final felling age) was also analyzed in this study.The thesis covers the analysis of five different fertilization scenarios, varying in fertilization intensity, from no fertilization at all, to fertilization at every Harvesting operation (thinning or final felling). A sub-study was also carried out so the reader in detail can see how the different fertilization scenarios affect individual forest stands of different nature. The analysis has been done with the planning tool PlanWise, which is an application of the Heureka analysis and planning system.
Exercise pens as an environmental enrichment for laboratory rabbits
This thesis analyzes the effects of different fertilization strategies on forest management at Holmen Skog in Umeå district. Harvesting volumes, net present values and fertilization intensity are presented for each fertilization scenario. The planning reserve (percentage area older than minimum final felling age) was also analyzed in this study.The thesis covers the analysis of five different fertilization scenarios, varying in fertilization intensity, from no fertilization at all, to fertilization at every Harvesting operation (thinning or final felling). A sub-study was also carried out so the reader in detail can see how the different fertilization scenarios affect individual forest stands of different nature. The analysis has been done with the planning tool PlanWise, which is an application of the Heureka analysis and planning system.
Ut ur Östersjön genom vassen : beskrivning av övergödningsproblematiken samt optimering av en reningsmetod genom skörd av vattenväxter
This study is based on AgroSeas business idea from environmental problems to valuable resource, with the objective to optimize a method to purify the already eutrophicated Baltic Sea by Harvesting water plants, mainly reed. The nutrients will then be recirculated to arable land through residues from biogas production. The amount of nutrients that can be removed by Harvesting the biomass
depends on the amounts of biomass and the nutrient content of it, which in turn is strongly dependent on the nutrient concentration of the surrounding water. Vegetation suggested in the study for an effective nutrient uptake is helophytes: reed, cattails, reed canary grass, reed sweet
grass in shallower water and lemnoideaes: duckweed and nymphaeids in the deeper parts.
Competitive species has high purification ability but requires regular maintenance to avoid channeling and overgrowth. Regarding time and method of harvest, effectiveness may be improved by: Harvesting plants above the water level and after flowering, a border is kept, Harvesting twice a season, a bigger machine and a regular maintenance.
This literature has illuminated a major environmental problem and it has been suggested
optimizations for a method for cleaning the Baltic Sea through Harvesting water plants, but to get a
definite answer for the optimal method for each site tests should be carried out, this because many
factors determine to what is suitable for each, specific environment.
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Analys av framtida potential för virkesköp från privata skogsägare i Västerbottens län : beslutsunderlag för virkesköpsstrategier
This study was conducted on behalf of SCA forest AB, Västerbottens forest administration. Timber procurement from non-industrial private forest owners has become an increasingly important part of SCA:s wood supply. The objectives of this study was to report the current forest conditions in the private forests in the county of Västerbotten, analyse the potential for procurement of wood from private forest owners, and provide a basis for decisions on future strategies for timber procurement from private owners.Material and data have been collected from different sources, mainly from Swedish National Forest Inventory and SKA-VB08. This material was the basis for the analysis and calculations performed with the Heureka application PlanWise. This study area was divided into six different analytical areas (Coastal south, Coastal middle, Lycksele, Inland south, Inland north, Skellefteå), where each area of analysis is represented by a number of municipalities.In this study, two scenarios were specified; one describing the current forest management with current Harvesting levels and the effects of these assumptions, the second to illuminate what potential there is for future timber Harvesting.
Vilken är den teoretiskt optimala toppdiametern på bokmassaved vid motormanuell avverkning?
The bioenergy market has been introduced relatively late in a perspective of the Swedish forestry. Nowadays branches and tops are used more frequently as bioenergy after Harvesting. Therefore, it has developed a competitive situation between pulpwood and bioenergy. This situation has even established some questions. Two examples of these are:
? At what top diameter should the final piece of pulpwood be crosscut to get the best economically result?
? Should the top diameter, at the final piece of pulpwood, be crosscut at a thicker or smaller diameter than what is done today?
The purpose of this report is to answer these two questions when the Harvesting is made motor manually in beech stands.
Jämförande tidsstudie vid riskörning med kompakteringsskotare och traditionell ?lätt? modifierad skotare :
This report is a thesis work for a B.Sc. in Forestry exam at the School for Forest Engineers, SLU.
The work was an assignment from Sydved Energy AB. The aim of the work was to compare the operational productivity between two kinds of forwarders for extraction of Harvesting residues, one forwarder with a special compression device and one ordinary, slightly modified forwarder.
Two sites were studied for each forwarder. The study shows that the annual production was about 11,000 m3 higher for the traditional forwarder. The cost for the traditional forwarder was SEK 0.9 lower per m3.
Biomassauttag vid delkvistat sortiment i klen gallring
The purpose of this study was to estimate the removal of biomass in connection with thinning operations in young stands that are dominated by small diameter trees. The economy of such operations depends on the products generated as well as the performance of the Harvesting systems. Conversion tables designed to predict the outcome based on Harvesting method was another goal of this study. Removal of biomass affects the nutrient composition of the site. Therefore it is a purpose that this study will provide researchers with some variables that can be utilized when studying this aspect.
Trees were harvested and divided into bunches based on diameter.
Analys av mjuka faktorer som påverkar grotuttaget från hygge till avlägg inom Sveaskogs organisation
Biofuels are getting more important as EU plans to replace fossil fuels with renewable energy sources. Because of that Sveaskog has chosen to invest in developing the handling process of logging residue. The company has a joined organisation for handling both round wood and logging residue. They are also working at integrating the forwarding of the logging residue with the rest of the Harvesting team. Sveaskog is currently extracting 44 % of the available amount of logging residue.
Utvärdering av en subjektiv metod för att skatta mängden trädbiomassa längs vägkanter :
Forest biomass is becoming an increasingly important source of renewable energy, and thereby the demand is increasing. There is currently 213 000 km of forest roads in Sweden that could be suitable for biomass Harvesting. Harvest of biomass along forest roads both provides biomass and maintains the quality of the roads. Currently, the volume of biomass along roads can only be assessed post harvest, chipping and industry deliverance.
As the decision of whether or not to harvest should preferably be based on more than experience, the TJ-method has been proposed. The TJ-method is a subjective method to quickly determine the dry matter quantity with the assessment being conducted from the roadside.
Planering av vägupprustning med hjälp av GIS och optimering : en fallstudie på Holmen Skog
The objective of this thesis was to develop a method for the planning of road upgrading at Holmen Skog, a Swedish forest company. A critical issue for creating such plans is to identify roads that are suitable to upgrade to a standard that can handle heavy traffic during spring thaw, since spring thaw is a bottle neck for transporting timber. The method was tested in a case study at a district.
The work consisted of two parts. The first was to retrieve and prepare geographical data for the roads.
Vad skapar stress respektive trivsel hos avverkningslag? : en jämförelse mellan bolags- och entreprenörslag
As a student during my studies, I have been told about entrepreneurs who have red numbers in their financial statements, and there is a forest machine operator shortage in Sweden. The basic idea of this thesis was to examine the underlying factors that may have caused the problems described above.
The aim of this thesis was to investigate the factors that create stress and job satisfaction as a forest machine operator. The study was performed as a comparison between forest companies own Harvesting teams and entrepreneur teams to investigate if there are any differences in stress and job satisfaction between the two different types of team. The study was conducted in collaboration with SCA Skog.
The material for this study was collected by doing interviews with SCA's Harvesting teams. A total of 27 forest machine operators were interviewed, divided into a total of 10 separate Harvesting teams.
It was very similar between the different type of teams, which situations the operators experienced stress.