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437 Uppsatser om Tree rings - Sida 4 av 30

Flygbildsanalys av trädskiktets status efter brand : en metodstudie

During the past years fire has been identified as an important factor for nature conservation in the forest landscape. To accurately quantify the size of a burnt area is obviously important, but also to quantify the degree of fire damage to the tree canopy. Such data are important for assessing the conservation value, and to support planning and management of the burned area in the future. I have examined how to estimate the status of tree crowns after fire from interpretation of aerial photographs. This is possible because fire changes the structure of tree crowns and this influences the colours in aerial photographs by spectral reflection. Included in the study are four areas, three of which burned in 2005 and one in 2006.

Product/Service-Systems ? en litteratur undersökning för att definiera och differentiera forskningsområdet

Inom industrin används olika testmetoder för att uppnå hög kvalitet i mjukvarukontrollerade system. Kvalitetskraven är särskilt höga för säkerhetskritiska system t.ex. styr- och reglersystem i fordon. I det här examensarbetet används två analysmetoder (Fault Mode and Effects Analysis och Fault Tree Analysis) för att ta fram ett nytt säkerhetstest för ett broms- och växlingssystem som Scania tillverkar. Det studeras även hur formella metoder kan användas för att ytterligare öka kvalitet ochh tillförlitlighet.

"I will go now to my pyre" : Isaks bindande läst genom J.R.R. Tolkiens The Lord of the Rings

This paper investigates the science fiction novels of Swedish crime writer Per Wahlöö, most famous for his collaboration with his writing partner Maj Sjöwall on the ten Martin Beck mysteries. During two important years, 1964 and 1968, Wahlöö wrote the novels Murder On the 31st Floor and The Steel Spring, set in a near future land ruled by a social fascist power structure where political opposition is eradicated. The pretexted notion of this paper is that these novels consists of extensive quantities of criticism against the Swedish welfare state and the monopoly-capitalistic Swedish press during the sixties. Through the lens of science fiction theory and the notion of the novels as historical sources this paper concludes that PerWahlöö´s science fiction becomes a bridge between the classic Swedish detective novel and the new social critic crime fiction in the style of Sjöwall-Wahlöö and others. The novels are also representations of the historical process in the mid-sixties during the radical turn: the sci-fi novels as social criticism of the contemporary society ? an utopian flare.

Ett träd för ett annat

This project is a collaboration with Ett Klick för Skogen, a foundation that buys and preserves endangered forests in Sweden. There are several ways of helping the foundation, e.g. buy a tree and for this the buyer obtains a symbolic diploma. Many organisations uses this method to collect money and for me the lack of a thorough expressions are consistent. The objective with this project has been to renew these diplomas for Ett Klick för Skogen and in the long run increase the collections and preservation of endangered forests in Sweden.The idea has been to vivify hardwood trees in a new and rather poetic than pedagogic manner.

Naturreservat : en bra naturvårdsåtgärd för att bevara enskilda arter och/eller bevara den biologiska mångfalden?

The examination of the adequate nature conservation methods in a natural reserve, to conserve a specific species and / or increase biological diversity is the subject of this study. This work is based on four species, that can be found during the Spring season, liverleaf, wood anemone, brimstone and woodpecker. The incidence and availability is studied and closely observed for these species in twenty forests, i.e. ten forests which are nature reserves and ten forests with the similar characteristics as the nature reserves habitat, but are not nature reserves in Gnesta mucipality, Södermanland. Measurements of the tree crown and the diameter of the tree trunks where noted to study how these factors could affect the outcome of the abundance and incidence of the four species.

Utveckling av gran, Douglasgran, bok och tall under skärm av hybridlärk :

?Development of Norway spruce, Douglas fir beech and Scots pine with a larch shelter wood? is a report written by Per-Olof Magnusson. The thesis is a compulsory part of forest engineer program at ?Skogsmästarskolan?, SLU, Skinnskatteberg, Sweden. The purpose of this report is to describe and evaluate an experiment with hybrid larch (Larix x eurolepis) as shelter wood, and different tree species growth and survival depending on the density of the shelter wood. The experiment is conducted by southern Swedish forest research centre, faculty of forestry, SLU in Alnarp. The hybrid larch ought to be an interesting alternative to birch (Betula sp.) as shelterwood on suitable sites in southern Sweden.

Hur ser lavars fördelning ut runt stammen på ek, och påverkas den av trädets storlek och dess närmiljö?

The aim of this study was to describe preferences of geographic direction of ten, oak-living epiphytic lichen species and how they responded to sun exposure, nearby bushes and trees, bark fissure depth and circumference. The frequency of every species was recorded in arcs of ten degrees around the tree at a height of 130 to 180 cm above the ground. An estimation of the amount of every species in every arc was also recorded. To analyse how the distribution of the lichen species responded to the different factors their concentration for every tree was plotted against the four factors. The distribution of Cliostomum corrugatum had a positive response to high sun exposure and a negative response to a thick layer of bushes and trees.

Volume and taper equations for Sitka spruce (Picea sitchensis (Bong.) Carr.), Norway spruce (Picea abies (L.) Karst.) and White spruce (Picea glauca (Moench) Voss) in Iceland

The aim of this study was to evaluate different types of volume and taper equations that can be used to predict single-tree stem volume and stem diameter at any given height along the tree stem for plantation grown Sitka spruce (Picea sitchensis (Bong.) Carr.), Norway spruce (Picea abies (L.) Karst) and White spruce (Picea glauca (Mounch) Voss) in Iceland. A number of published tree volume equations were tested and modified to predict the total stem volumes over bark but three logarithmic equations were taken for more in-depth analysis. Three taper equations were tested. Two variable-exponent equations (Kozak 1997, Kozak 2004) and one exponential equation described by Biging (1984). Data from a total of 617 sample trees were used in this study, collected from stands in various parts of the country and present different types of stands growing in different soil types and cover most of the site conditions suitable for forestry in Iceland.

Trädslagsinverkan på markvegetationens utveckling i odlingsförsök med tall och contorta :

In the 1970?s it was predicted that in the beginning of the 21st century there would be a timber shortage in Sweden and a large scale introduction of the exotic tree species lodgepole pine started. An introduction of a foreign tree species means a risk of a negative influence on the forests ecosystem. Today, the stands that were established in the 70?s are middle-aged and the effect on the forest floor vegetation can be studied.

Potentiella arealer för ökad virkesproduktion i norra Sverige genom skogsodling med Pinus contorta var. latifolia, Larix sukaczewii, Abies lasiocarpa, Populus × wettsteinii och Picea mariana

Sweden is a country with few native tree species. According to Govt. 2007/08: 108, exotic tree species may be seen as an opportunity to increase the growth of tree volume in Sweden. Potential areas where explored In this work for cultivation with Pinus contorta var. latifolia Engelm., Larix sukaczewii Dylis, Abies lasiocarpa (Hook.) Nutt., Populus × wettsteinii Hämet-Ahti (tremula x tremuloides) and Picea mariana (Mill.) Britton et.al.

Lämpliga främmande trädslag för Kalmar och Mönsterås kommuner

This report concerns the for Sweden foreign tree species hybrid larch, hybrid aspen and poplar, and focuses on the area Kalmar and Mönsterås municipalities. The report shows that there are not only advantages with these species. The larch, the most common of the alien tree species has the greatest problems due to that its timber is difficult to sell in the area but also the Larch´s poor pulp quality and is more likely to be damaged by wildlife than the spruce is. Hybrid Aspen is much easier to sell and is used like regular aspen for match wood and textile pulp. Its disadvantage is the high cost for plants and to prevent damage from wildlife.

Utbyte av massaved och biobränsle i några typbestånd av Contorta :

The aim of this study is to describe a number of type stands of lodge pole pine in Norrbotten with respect on stem volume and total biomass. Further questions to answer is if there is stand characteristics that make the stands more suitable for pulpwood in early thinning, or if it is better to apply whole tree harvest. The study shall also give an indication if bio energy can be an economical interesting alternative for Sveaskog. Sampled trees represented the variation in the different stands. Five trees were selected from each stand to represent that stand. Stem volume and biomass (kg dry weight (DW) per hectare) for each fraction was calculated.

Planteringsförbandets inverkan på bestånd av contortatall (Pinus contorta var. latifolia) med avseende på volymtillväxt och virkesegenskaper

At the beginning of the 1970´s forestry feared an imbalance in the future wood supply. Because of this anticipated "timber slump" forest companies undertook a variety of measures to counter this. One of these measures was the introduction of exotic tree species. The choice finally ended up with lodgepole pines which were considered a fast growing tree species compared to our native tree species. Theambition for the new lodgepole pine stands were to run these with rotation periods of between 40-60 years, thus smoothing out the ?timber slump? that was anticipated.

Rum och rörelse - analys av alléns betydelse för människa och landskap

Within literature, politics and science, there is a claim that ?tree avenues are important?. But the question and the goal for this essay are to explore the pretext to how and why. Planting tree avenues is a 4000 year old tradition and they are a common element in the Swedish and Scanian landscape since the 18th century. They were first mainly planted by aristocratic land-owners or on their initiative, but since the 19th century also by farmers.

Prestationspåverkan av flerträdshantering i klena gallringar

The aim of this study is to investigate how multiple tree handling harvesters perform compared to earlier developed standards. The study shows that multiple tree handling harvesters are more efficient in thinnings stands with mean stock volumes less than 0,12 m3fub per stock. The increased efficiency is different for different mean stem classes. In stands with a mean stem volume of 0,04 m3fub per stock, the increase can be as high as 40 percent while it is about 10 percent in stands with a mean stem volume of 0,12 m3fub. Comparisons have been done between stands that are felled with partly limbed stands and stands without partly limbed assortments. The difference in performance is clear and shows that the partly limbed assortments strengthen the multiple tree handling harvesters positive effects in low dimension thinnings.

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