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681 Uppsatser om Soil moisture gradient - Sida 31 av 46
Föryngring och produktion av skog på torvmark
Kunskapen kring svensk torvmarksbeskogning är undermålig. En kunskapslucka som till stor del beror på att torvmark tidigare bedömts som ointressant mark i samband med skogsproduktion. Detta beror mycket på det svenska regelverkets restriktioner mot markavvattning och gödsling samt miljöaspekterna som berörs och den aktivare skötsel som krävs. Det ökade behovet av skogsråvara gör att skogsbruket söker nya marker där torvmarken har potential att etableras för skogsproduktion.Studien är en kunskapssammanställning som lyfter fram kunskap kring skogsbruk på svensk torvmark med fokus på föryngringsprocessen. Finland använder torvmarker i skogsbruket på ett sofistikerat sätt.
Jämförelse mellan sådd och naturlig föryngring av tall i Härjedalen
The purpose of this study was to compare naturally regenerated Scots pine (Pinus sylvestris (L.)) against seeded Scots pine in terms of benefits and differences. An inventory was performed at a number of different sites, 4 ? 6 years after soil scarification and data on the number of new established plants, their height growth as well as ground-line diameter was collected. Information about site conditions such as altitude, quarter exposure and frost risk was also collected. A review of previous studies was conducted in addition to the field study.
Svartgran ? ett alternativ när allt ser mörkt ut? : en kartmodell för att visa lämpliga ståndorter för odling av svartgran
A common problem in forestry is plant death caused by frost. The risk of frost is highest on wind protected, flat or low-lying areas in the terrain. Here you often have regeneration problems with Norwegian spruce which is especially sensitive to spring frost. Swedish tree experiments have shown that the black spruce can be a suitable alternative on these areas, for example on moisture frost prone areas. The species originates from North America and its pioneer tree characteristics make it more frost hardy than Norwegian spruce.
Erosionsskydd i strandzoner :
Erosion in coastal areas is a common problem all around the world. The range of the problem depends on several factors, i.e. type of bed-rock and soil, wind and wave climate. Another factor is whether the area is of high interest, i.e. if the area is important for tourism and recreation, if there are houses and other buildings close to the shoreline or if it is a site of special scientific interest.
Stubbtransporter - en jämförelse av tre olika transportsystem
In Sweden, the demand for bio energy has increased in recent years due to the current energy and climate debate. In 2008, the energy supply of Sweden was 612 TWh, biofuels accounted for 123 TWh of these. Stumps have been highlighted as a potential fuel in recent years and the Swedish Forest Agency expects a technically and biologically feasible potential of 20.7 TWh annually between 2010 and 2019. The idea of utilize stumps is not new. During the 19th century stumps were used for tar production and during the 70?s and 80?s attempts were made to use stumps in the pulp industry.
Odlingsstrategier på organogena jordar : en studie om beslutsfattande bland KRAV-anslutna lantbrukare
This study examines how farmers certified by KRAV face proposed regulations on organic soils put forward by KRAV economic association among others, and how they are affected economically. These soils are, from an environmental perspective, interesting as a target for production regulations as they cause greenhouse gas emissions through decomposition of organic material when cultivated. The regulations advocate that organic soils should be grown with pasture where soil cultivation is only allowed every fith year which implies that possible adjustments of cultivation have to be made in order to fulfill the regualtions. Collection of data have been made through a questionnaire sent out to 574 farmers certified by KRAV. The answers have been analysed using a decision making model and statistical findings suggest that proportion of organic soils, type of production, economic conditions and farmers? goals and values have an influence on whether the regulations and potential cultivation adjustments have been considered or not.
En undersökning av framtidametoder för att säkra förband i produktion
The thesis is an examination of the methods that are appropriate and long-term choice to obtain clamping force and secure screw joints in production. The employer, Scania CV AB, transmission manufactures axle gears to all trucks produced in Södertälje. One of the most common assembly elements is screw joints, where the clamping force is essential to achieve a secure joint. Current methods to secure the joint is due much of the friction effect and is an indirect method to measure the clamping force. The clampforce accuracy becomes more widely with torque angle control.
Skydd mot yterosion i slänter av finmorän
Slopes in fine till soils are exposed to surface erosion due to rainfall, snowmelt and upland water sources. Large areas of road slopes are therefore covered for surface erosion protection. Preventive methods like ditches and trenches are also being used. Silt tills are particularly troublesome since the water can bring the soil into suspension and cause mudslides. Different methods for erosion protection have been studied in this work, with the emphasis placed on rockfill covering. The need for and the dimensioning of this type of covering has been examined in literature and field studies.
Att utkräva ansvar - en analys av Vattenfalls verksamhet i Tyskland
With the expansion onto the international market almost a decade ago, Swedish energy corporation Vattenfall began it's breaking and burning of coal on German soil. Criticism aimed at Vattenfall peaked in the mid 2000s with the revelation of large quantities of carbon dioxide emissions and the re-location of villages and graveyards in German states Brandenburg and Saxony. The purpose of this thesis is to show where the responsibility for these activities lie. By analyzing the history of, and the political debate surrounding, Vattenfall, I will show that the prevailing policies of right- as well as left-wing parties in the 20th century were all, regarding this matter, market oriented. I will also show that these market promoting policies made possible a situation where the transparancy of, and state control over, Vattenfall were close to eliminated.
Structure and tree diversity of lowland limestone forest on Seram Island, Indonesia
There have previously been very few studies of forests on Seram Island in the Eastern Indonesian archipelago and none before on lowland limestone primary forests. The COLUPSIA project on collaborative land use planning has therefore chosen Seram as one of two project sites. The objective of the COLUPSIA project is to establish collaborative and equitable land use planning. In order to achieve its objective the COLUPSIA project aims to improve understanding of traditional resource management and how it interacts with governmental systems, as well as enhancing knowledge about tropical landscapes and ecosystem services.The aim of this study was to contribute to the COLUPSIA project through describing lowland limestone forest on Seram Island in respect to (1) forest structure, (2) tree species richness and (3) tree species composition. We set up 5 plots, each of 0.2 ha, at one site, Mawalai, and collected data on tree variables (tree diameter ?10 cm) as well as for some other life forms and environmental data.
Möjligheter att förutsäga kvävegödslingsbehov i höstvete med Yara N-tester
The Yara N-Tester is a handheld chlorophyll meter which can be used in several different
crops as an aid to determine if there is a need of complementary fertilization with nitrogen
(N) or not. If the crop requires more N the N-Tester will recommend an amount in kg per ha.
The possibility to assess the need of N depends on the strong relation that exists between
chlorophyll- and N-concentration in the leaves of plants. In the multiannual trial series
?Nitrogen to winter wheat at different soil conditions? measurements with the N-Tester was
carried out at flag leaf emergence (GS 37). In this work the result of measurements, the NTesters
ability to estimate the need of N in winter wheat, will be presented for the years
2008-2011.
Kvickrotsstudier: 1. Kvickrotens reaktion på myllningsdjup, kvävemängd och kväveplacering i konkurrens med gröda. 2. Reducerad glyfosatanvändning på trädad åkermark :
1. Reaction on burial depth and nitrogen availability and placement in competition with a crop
In this trial it was investigated how couch grass (Elymus repens) changes its ability to compete in stands of wheat and barley with different burial depth and different amounts and placement of nitrogen. More knowledge in this area can be valuable in the attempt to decrease the use of herbicides and still keep the weeds under control.
The trial was carried out in the summer of 2004 as an outdoor pot experiment. The pots contained 15 litres of soil with a surface of 0,06 m2.
Förbränning av pellets framställda av defibrerad granråvara :
Fuel pellets are in Sweden mainly produced from sawdust and cutter shavings. Before the pelletising process the raw material is dried to attain consistent moisture content and ground up in a hammer mill. In the densification process (pelletising) the ground material is forced through holes in a rotating die. This heats up the wood particles which cause them to soften and self bond. After the process the pellets are cooled, sieved and bagged.
The milling process creates a wide range of particle sizes.
Development of real-time RT-PCR for the detection of human sapovirus in foods
Food-poisoning is a major health problem and an estimated half a million Swedes are food-poisoned annually, with acute gastroenteritis as a consequence. One of the major causes of contaminated foods is related to food- and waterborne viruses. To be able to trace back the source of contaminant, the method of detecting viruses must be specific and sensitive. No standardized method for detecting foods for sapovirus exists today.
The aim of the work described in this bachelor thesis is to implement and opti-mize a real-time RT-PCR method for the detection of all genogroups of human sapovirus in foods.
Fuktens påverkan på utegipsskivor under byggtiden
This thesis is a study of humidity at Knauf Danogips external plasterboard. The study is performed at the building project Kv. Maskinen in Jönköping in cooperation with NCC Construction AB and Knauf Danogips. The measuring was performed during five winter/spring months to see how the weather influenced the plasterboard.The measuring was performed at a small two-storied building and a larger fourstoried building. From the buildings` placement were a couple of measuring dots selected and to get a good result was the dots located in the four cardinal points.