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1178 Uppsatser om Forest road - Sida 39 av 79
The effects of mother trees and site conditions on the distribution of natural regeneration establishment in a Bornean rainforest disturbed by logging and fire
In the tropics, logging and wild fire can result in degraded secondary forests with lower biodiversity than in the natural forest. One way to limit forest degradation is to rehabilitate the present large areas of secondary forests. However, there is a lack of knowledge concerning the ecology of tropical tree species and further studies would be advantageous for future rehabilitation efforts of degraded rainforest. The objective of this study was to investigate how mother trees in secondary forest and different site factors affect the abundance and spatial distribution of natural regeneration of non-pioneer tree species in a tropical rainforest in Sabah, Malaysia.
The study took place in the INIKEA Forest Rehabilitation Project area, which suffered from wild fire in 1983 and has been selectively logged over both before and after the fire. Natural regeneration and site variables were inventoried in plots, while mother trees were inventoried in the whole survey area.
Det gör ont när stockar spricker!
The aim of this study was to provide SCA Forest Norrbotten District with material to assist in their work towards decreasing the frequency of bucking splits in their saw timber logs. SCA Forest supplies the Munksund sawmill with pine timber. Periodically the sawmill experiences problems related to bucking splits in their logs.
The purpose of this study was to find an available method to measure the occurrence of splits directly on incoming timber. The ambition was also to gain some knowledge about possible variations between different logging crews in terms of split frequency. If possible, this information could be used to investigate if certain crews produced more splits than others, and thereby making it possible to provide feedback to the logging machine operators.
The study consisted of two major parts, a literature review, and a practical sawmill study.
Fo?rutsa?ttningar fo?r elektrifierade lastbilar med eHighway inom svensk gruvindustri : En ja?mfo?relse av olika transportslag mellan Mertainen och Svappavaara
The Swedish government has a goal of achieving a fossil-free vehicle fleet in 2030. Heavy transport constitutes a significant part of Sweden's transportation sector and the vehicles are driven almost exclusively by fossil fuels. Siemens has developed eHighway, a concept for electric road systems enabling electrification of trucks, in order to reduce the environmental impact of heavy transports. This study aims to investigate the potential that eHighway has on transporting iron ore from the mine of Mertainen to a processing plant in Svappavaara. Electrified trucks are compared with conventional trucks, and diesel and electric trains.The evaluation was made with respect to energy consumption, environmental impact, and cost.
Förekomst av törskate (Cronartium flaccidum, Peridermium pini) på tall (Pinus sylvestris) i relation till markfuktighet och fältskikt : en studie om 2000-talets törskateepidemi i norra Sverige
Resin-top disease is a rust fungi that occurs both as a host alternating form, Cronartium flaccidum G. Winter., and as a non-host alternating form, Peridermium pini Pers. The host alternating form can use a variety of hosts but the most commonly used species in the boreal forest is Melampyrum sylvaticum. In Scandinavia the Resin-top disease infect Scots pine, Pinus sylvestris L. The fungus infects the needles through the stomata and then grows through the branch to the stem where it strangulates the vessels transporting water and nutrition to the treetop, which kills the top.
Avsättningsmöjligheter för slaggrus från avfallsförbränning vid Åmotfors Energi
The incineration of waste is steadily increasing in Sweden and so is the production of ashes. The bottom ash has for many years been used as construction material in
landfills. Now many of the nation's landfills are closed and there is a great need to find another beneficial use for the ash. Bottom ash is a gravel-like material and with its material properties it can replace natural gravel in parts of roads and surface constructions. Today this use is only approved within landfill areas where leachate is
collected and checked.
Goliatmusseron (Tricholoma matsutake) - kräver den en kontinuitet av träd? :
Modern forestry management may disadvantage some mykorrhiza forming fungi because; they are dependent on late successions and cannot survive the constantly recurring breaks in the continuity of their host tree. For this study the specie goliatmusseron (Tricholoma matsutake) was chosen to investigate this possibility. In Sweden T. matsutake is found in greatest amounts north of Örnsköldsvik on glacifluvial sandy soils in association with pine trees and reindeer lichens.
Seventy two forest stands where the specie previously had been found were studied; 62 in the northern part of Sweden and ten in the southern. Several indicators were studied to find out if these stands have had a continuity of living trees.
Bokhögstubbar i Klåveröds strövområde : utbredning, egenskaper och betydelse för rödlistade vedlevande skalbaggar
Lack of dead wood is the main cause of decaying or loss of populations for many
forest species. To increase the amount of dead wood is a prerequisite to maintain
biodiversity in forests of northern Europe. In summer 2006 the recreation area
Klåveröd, at Söderåsen in Skåne, Sweden, has been inventoried for high stumps
(snags) of beech, (Fagus sylvatica). The result of the inventory has been compared
with data of the real estate and forest management directories from the owner,
region Skåne. The results have also been matched with the results from an
inventory of saproxylic beetles in 2005, performed with windowtraps on selected
snags both in the area and the adjacent national park Söderåsen.
594 snags were found on 747 ha.
Sortimentsinriktad avverkning
Forest enterprises have always searched for ways to improve efficiency. For the past few
years there has been an emphasis on stock-keeping levels. Increased demand for fresh
round timber and the need to decrease the amount of tied-up capital has made the forest
industry reduce its inventory levels. This has brought on a higher demand on the timber
supply from the forest management districts concerning both delivery in time and
assortment output. As a result, the flow of timber has fluctuated a lot with serious
consequence for the timber supply during 1994.
Spatiella mönster och lager av organiskt klor och klorid i barrskogsjord i sydöstra Sverige
The concentration and storage of organic chlorine and chloride were determined in soil, to a depth of 40 cm, in a coniferous forest in the Stubbetorp catchment area in south-east Sweden. Also, the spatial distribution of the two forms of chlorine was determined. Soil samples were collected at 49 of the nodes in a grid with approximately 105 m between the nodes. The analysis of spatial variability suggested that no spatial autocorrelation was present either within the variable organic chlorine or chloride. This means that no sample was more influenced by another nearby sample, as compared to other samples further away.
Stormskador i stickvägsgallrade bestånd i sydvästra Sverige :
A storm in January 2005 felled 75 millions cubic metres of forest in South Sweden. Previous studies of wind damage in thinned stands indicated the importance of early thinnings. The risks of wind throw increased by increasing age and height of the stands. Previous studies also indicated increasing risk of wind throw along the strip roads. The aim of the present study was to investigate wind damage in Norway spruce stands in South Sweden in relation to time of the first thinning and different pattern of strip roads (width, length and direction).
Vart är naturen i skärgården på väg? : skogshistoria på Ängsön-Marskär i Stockholms södra skärgård
The following thesis is a study of the forest history on the island of Ängsön-Marskär concentrating on the last three hundred years. The island is located in the administrative province of Stockholm, the local community of Haninge and it is situated approximately seven kilometres east of the island Ornö in the south of the Stockholm archipelago. The questions this thesis attempts to answer are: How where the natural resources on Ängsön-Marskär used through the centuries? How has the state of the forests developed since the 16th century? How will the nature develop onwards? The thesis is based on archival sources for Ängsön-Marskär and the surrounding areas. A field study was conducted where the entire island was investigated using an objective forest inventory method.
The first map material existing over Ängsön-Marskär is from the year 1711.
Kvalitetssäkring av markberednings- och planteringsuppföljning hos SCA Skog AB Jämtlands skogsförvaltning :
Quality assurance means to systematically work for better understanding of the customers needs, demands and expectations. The goal for this study was to investigate how quality can be assured in the job follow up that is made by forestry contractors after soil scarification and planting. The study consisted of a description over the current follow up process at SCA forest AB Jämtlands forest administration, analysis of current follow up situation and an investigation of follow up process made by contractors in other line of business.
The first step was a statistical comparison where the own follow up made by contractors were compared with follow up made by SCA them selves over 100 stands. Two soil scarification contractors and two planting contractors carried out the silvicultural measures. The results showed that significant differences between a number of quality factors measured, for example number of approved plants or approved scarification points, average score on stand and number of totally planted plants.
Överlevnad, tillväxt och skador i planteringar av sitkagran (Picea sitchensis) efter stormen Gudrun
Sitka spruce (Picea sitchensis (Bong.) Carr) is just like Norway spruce (Picea abies) a species in thegenus picea. The natural range of Sitka spruce is a narrow strip along the west coast of North America. Itis the most coastal of all picea species, and very dependent on the mild and humid climate along thepacific coast.Sitka spruce has been grown a long time in the countries around the North Sea, particularly in GreatBritain where it currently is the most important species in British forestry. Sitka spruce has not beenplanted in Swedish forests to any large extent before the storm Gudrun in 2005. Several studies indicatethat the production of wood biomass is higher for Sitka spruce compared to Norway spruce.
När cykelstigen kom till byn : en fallstudie i Arvidsjaurs kommun
Den omfattande exploateringen av Sveriges skogar under 1800-talets andra hälft ledde till en motreaktion där tankar om uthålligt skogsbruk etablerades i början på 1900-talet. Detta fick till följd att efterfrågan på arbetskraft ökade i de norrländska skogsbygderna. Framkomligheten var inte bara ett problem för skogsbruket, även befolkningen i Norrlands inland var i stort behov av utfartsvägar som komplement till kommunikationen längs älvarna. En åtgärd som vid tiden föreslogs för att komma till rätta med den svåra framkomligheten i det norrländska skogslandskapet var byggnation av en enkel typ av vägar. Cykelstigarna var, som namnet antyder, tänkta för persontrafik i första hand med cykel och motorcykel.
Utveckling av Mätmetoder för Färdmotstånd
The student project Elba at KTH started in 2011 and is a project where a battery driven prototype car is developed. The vehicle competes in Eco Shell Marathon in Rotterdam, Holland. In this competition the vehicle that travels a certain distance including several starts and stops with the lowest energy consumption wins. To minimize the consumption is therefore very important, which requires knowledge of the vehicles energy losses.A vehicle's energy losses depends on several factors and can be divided into the powertrain efficiency and the driving resistance. The driving resistance can then be divided in to rolling and air resistance, if smaller losses like vibrations are ignored.