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268 Uppsatser om Biomass harvest - Sida 5 av 18
Distribution of wild boar (Sus scrofa) damage and harvest loss in crop fields
The last decades the populations of wild boar (Sus scrofa) has increased rapidly over the species? entire European range, including Sweden. This is followed by increasing human-wildlife conflicts as a result of the wild boar foraging behavior, causing damage to agricultural crop fields due to trampling and feeding. To be able to minimize damage we need more knowledge of where in the fields the risk of damage is high and what features in the landscape that affect this risk. I analyzed damage distribution in relation to the distance to six different landscape features; forest, road, ditch, building, game field and bait station, in the study area, the Island Mörkö in eastern central Sweden.
Torkning av flis med restvärme : Metoder för att sänka återledningstemperaturen
The purpose of this study has been to evaluate whether a Low temperature bio-mass dryer could be integrated with the local district heating system in Malå. The aim is to increase the thermal efficiency of the cogeneration plant in Malå, by lowering the temperature of the cooling medium. Another benefit that comes from this is improved combustion efficiency at the power plant, since drying the fuel causes an Increase of the heating value.Simulations has been made in Excel, and with use of linear regression, to find out if it is profitable. Data for this purpose has been supplied by the power company Skellefteåkraft and furthermore SMHI.The result of the Calculations shows that a very efficient bio-mass dryer is needed, if yield of investments should be made possible. An Investment of 4,27 Mkr, in a dryer, could at a such criterium return 60000 kr/year, if the price of the biomass is 190kr/MWh.
Nitrogen fixation among boreal feather mosses along a clear-cut chronosequence
The Swedish boreal forests are limited by nitrogen (N) availability. While biological N2 fixation by cyanobacteria hosted by pleurocarpous feather mosses are important sources of N input to natural boreal forest ecosystems, little is known about the patterns of N2 fixation in silvicultural systems. This study investigates the biological N2 fixation rates of two boreal feather moss species (Pleurozium schreberi and Hylocomium splendens) along a chronosequence from clear-cut to mature forest, as well as the vegetation characteristics along the chronosequence. Measurements and samples were collected from 32 forest sites that were classified into four age classes (clear-cut, pre-commercially thinned, thinned and mature forest). The sites were located near the city of Arvidsjaur in northern Sweden.
Taktisk planering med geografisk hänsyn : fallstudie med Heureka PlanVis på SCA Skogs distrikt Liden
SCA is the largest private owned forest owner in Sweden, with an ownership of 2 million hectares of productive forestland. To manage the planning of such large areas and to fit the traditional organization structure of a Swedish forest company, the planning approach is subdivided into three stages; strategic, tactical and operational.
The strategic part, based on a statistic sample of stands, returns a harvest level estimate which should then be implemented at actual sites in the tactical part. This procedure can lead to incompatible solutions as the strategic solution is not necessarily possible to translate into actual sites in the tactical plan. The geographic aspect is important in tactical planning due to the large costs for moving equipment and maintenance of a large number of forest roads.
Sjunkande pH i Västerbottens humuslager : en kvantitativ analys
Acidification is a central concept in the environmental debate. The effect of acidification of the soil is a matter of a decreasing amount of cations and thereby a decreasing ability to resist a supply of hydrogen ions to the soil. Acidification has gradually increased in the O horizon in Västerbotten over a 30-year period from the 1970th to the 1990th. The aim of this study was from inventories of The Swedish National Forest Soil Survey and The Swedish National Forest Inventory explain and quantify the acidification that has occurred in the O horizon of two regions in the north of Sweden. Data from SMHI, The Swedish Meteorological and Hydrological Institute, has also been used.
Utvecklingen hos nattskatta (Solanum nigrum L.) och dess bekämpningsbehov i konservärtsodling :
Black nightshade (Solanum nigrum L.) is a major problem in gardenpea cultivations
contracted by Findus AB, a Swedish food processing company. The main problem is that the
nightshade berries contain solanin and, thus, are not tolerated in the marketed product, which
is fresh frozen peas. In addition, berries have the same size and color as the peas and cannot
be separated at the factory. Black nightshades have the last ten years become a more common
weed in field grown vegetables in the southern parts of Sweden. This MSc thesis presents an
experiment conducted in 2005, aiming at developing a tool for predicting the need for control
of black nightshade in peas.
Samband mellan laserdata och fältdata
To make it easier for forestry planning the forest owners needs data which describe characteristics of the forest. Such data you usually get from some type of inventory. A relatively new technology which probably is getting more important in the future, is laser scanning because of lower costs. But because the laser technology is relatively new you need to compare it with conventional inventory technologies to get better understanding of the possibilities the laser technology gives. This work intends to estimate field measured characteristics of the forest from laser data with help of regression analysis and then see which of the field measured properties that best could be estimated and which laser variables that gave the best results.
This study shows that heights has the best estimates, but biomass, diameter and volume also gives good estimates.
Den öländska älgstammens förvaltning : en granskning av förvaltningsplanerna och jaktens upplägg
To Swedes in general and, to hunters in particular, there is a great interest for moose (Alces alces), witch is Sweden?s largest deer species. In the province of Öland (Sweden?s second largest island) the local people show a great interest for the moose existence, both for consumptive (hunting) and non-consumptive use (tourism). This became apparent in 2002 when the moose hunters on Öland voluntary agreed to temporarily postpone the moose hunt on the island.
pH-sensitivity in boreal streams ? the influence of landscape characteristics
The goal of the society to increase the proportion of renewable energy has led to an increased demand of bioenergy e.g. forest biomass. However, there are concerns that removal of biomass will lead to decreased base cation concentrations in the soils and acidification of streams. In order to find in which types of landscape removal of branches and tops could have such negative effects, this study aims to analyse the relations between pH-sensitivity and landscape variables in the Bothnia Bay water district. GIS and digital geographical data were used to analyse the landscape in subcatchments.
Kolbalansen vid olika skötselstrategier för skogen på Tagels fastighet.
Since the 19th century the concentration of CO2 in the atmosphere hasincreased by 40 percent as an effect of the use of fossil energy sources.Increased concentration of CO2 will likely lead to increased temperature,changes in precipitation, rising sea level and increased frequency of extremeweather like storm events. A step to reduce emissions of CO2 and mitigateclimate change, for the property of Tagel, can be to adopt new silviculturalstrategies and analyse which is the most effective. As a result of that, threescenarios was produced, business-as-usual (BAU), increased set aside landand energy. An introduction of windpower at Tagels estate (property) andeffects on carbon balance was also examined. By using the Heureka systemand LCA-analysis in this study, it showed that the scenario of increased setaside land was the most efficient way to reduce carbon dioxide (CO2)emissions for the analysed period of 100 years.
"De tycka emellertid av gammal vana att det smakar gott, och tro dessutom att det är bra för hälsan" : samiskt växtutnyttjande från 1600-talet fram till ca 1950
Meat and fish was the most important food for the Sami people in northern Scandinavia until the beginning of the 20th century. It is not so well known that the Sami people also used a lot of wild plants as food and medicine although that kind of food was relatively common among them until the end of the 19th century. The purpose of this master thesis has been to describe which plants the Sami people used in general and also which plants were the most commonly used, and when and how these plants were harvested. I also wanted to measure the quantities of Angelica archangelica and Rumex acestosa within traditional harvest sites. Furthermore I wanted to find out if the plant use differed among Sami groups geographically.
Den licensierade vargjaktens betydelse för vargstammen
In October 2009, a new decision was made concerning the administration of predators which resulted in a new wolf policy in Sweden. This meant that the wolf population now should be limited to 210 individuals by harvest. The new policy also recognized that the public acceptance of this species must increase and the genetic status improved. In the 17th of December a decision was taken by the Swedish parliament that it should become legal to hunt wolves in Sweden. The wolf hunt resulted in debate on a large scale amongst people, some thought of it as a good decision while others thought it was wrong.
Obtaining high quality textile fibre from industrial hemp through organic cultivation
AbstractThe urgency to find alternative fabrics to conventionally produced cotton is increasing as vast amounts of agrochemicals are used and a lot of irrigation is required. In this literature survey the potential of organic cultivation practices to produce highly qualitative hemp fibre, suitable for the textile industry, was investigated. The definition of a fibre in the textile context as well as of the qualities that are essential for a textile fibre was necessary as a base for the discussion in this thesis. The quality parameters looked at were fineness, strength, length, friction, and colour. The impact of external growth factors and plant development on these quality properties are discussed.
Uppfångning och kvarhållning av 134Cs och 85Sr i olika växtutvecklingsstadier
Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in the event of rainfall. An increased level of radioactivity in the plants may occur due to interception and retention of the radionuclides. If the content of the plants is above the threshold limit value, entire yields may have to be destroyed. In order to prevent contamination or decrease the content countermeasures can be taken. The impact of the
biomass, leaf area index (LAI) and growth stage of the plant on the interception and retention is important to know in order to decide which countermeasures to use.
Weather may also be an important factor.
In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley and spring oil-seed rape was studied.
Energy efficient storage of biomass at Vattenfall heat and power plants
Storage of biomass is often associated with problems such as heat development, dry
matter losses and reduction of fuel quality. The rise in temperature can potentially
cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles
can cause health problems in the surrounding. The dry matter losses and reduction of
fuel quality can have economical effects. The aim of this thesis project is to develop
guidelines on how to store large amount of biomass at Vattenfalls heat and power
plants in an optimal way.