This thesis is about Christmas tree plantations in Sweden, and if its profitable to produce Christmas trees in Sweden. Sweden has 4,3 million households, 3 million of these households buys Christmas trees. 80 % of these Christmas trees are Norway Spruce (Picea abies), which is the most common Spruce in Sweden. Every year over 170 000 Christmas trees are imported to Sweden. The main import comes from Denmark.

After the storm Gudrun in 2005, the Swedish Transport Administration started clear-cutting of railroad corridors to reduce the risk of trees falling down on the tracks. Simultaneously, train accidents with moose and roe deer have become more frequent and the costs for consequent delays and repairs of engines are of growing concern. There is reason to assume that tree-clearance of railroad corridors may have contributed to an increase in number of accidents with moose and roe deer because the cleared areas provide attractive forage and thus may attract wildlife. The objective of my study was to investigate how clearing of trees affected the number of accidents with moose and roe deer. I compared deer-train collision frequencies before and after clearance of the selected railroads and compared these with uncleared control railroads in a BACI (before-after control-impact) approach.

Human presence has always influenced the surrounding areas, the forest as well. Structure and species composition have changed during human land use. Knowledge regarding these changes should be of great interest for conservation and forestry. We have analyzed human impact on the tree species composition on five study sites during 2000 years in Ångermanland, Sweden. More specifically the change in tree species composition in percentage amongst alder, birch, spruce and pine over time.

AbstractIntroductionOccurrence of bacteraemia and fungemia is a serious condition with high mortality and the incidence is increasing worldwide. The aim of this study was to survey the occurrence of bacteria and fungi in blood cultures from adult patients domiciled in the county of Gävleborg during one year and also to calculate the incidence and mortality in the same geographical area.MethodThis is a descriptive epidemiologic study, based on all episodes of blood cultures analyzed at the Microbiology laboratory, Gävle hospital during 2005. Patients from 20 years of age, domiciled in the county of Gävleborg at the date of drawing the blood culture, where included in the study. Criteria of exclusion were negative blood cultures and cultures which were classified as contaminants.ResultsAltogether there were 4 564 blood cultures analyzed, resulting in 524 (11 %) positive cultures for further study. There were 442 patients (48 % women) involved in 499 episodes with confirmed bacteraemia or fungemia.

In Uganda, small scale pig production plays a major role for households to earn a living and to secure their access to meat. Piglet mortality due to diar-rhoea-related dieseases is high. In an attempt to understand the underlying causes for this high mortality this study aims to investigate the role of trans-missible gastroenteritis virus (TGEV) and is a part of a larger project con-ducted at Makerere university in Uganda. A complicating factor in this investigation is the porcine respiratory corona-virus (PRCV), a stabile mutant form of the TGE virus. The occurrence of this virus had shown to alter the impact of TGEV in e.g. Europe and North Amer-ica.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree.

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.

The rainforests of the world are important not only to the countries in which they grow but to the world as a whole. They influence oxygen and water circulation as well as carbon sequestration which in turn affect global radiation and global warming. The forest also have great value and in Malaysia as in many other tropical countries large volumes are harvested which leaves great areas of degraded forest with little growth and biological diversity. Due to their low financial value these forests are often transformed and used for other purposes than forestry such as oil palm plantations. The trees are often transported out of the forest using large bulldozers. They are heavy which causes compaction of the forest floor and during transport the top soil layers are moved to improve mobility.

In Sweden and in Scandinavia the amount of tree species are rather few. However many different forms of trees arise due to mutations and gives rare appearances like cut-leaved and hanging forms. In some cases these trees are interesting as cultivars and a few of them have become popular garden trees. The knowledge of the original trees and early propagation is meagre.In this study a selected group of trees were found through search of literature. Eight tree forms were chosen and investigated in situ.

The storm Gudrun in 2005 led to massive windthow damage in forests in southern Sweden. Since then there has been a growing interest in factors influencing wind damage in above all Norway spruce (Picea Abies) stands. Although many other interesting areas still need to be examined. In 2005 there where a lot of stands that suffered different degrees of damage, a lot of these stands weren?t cut, but instead left to grow. The future development of these stands is uncertain and the guidelines are unclear.

White-Nose Syndrome, WNS, is an emerging fungal disease in the Northern American bat population causing mass mortality in infected hibernacula. Geomyces destructans is a newly discovered psychrophilic fungus causing WNS but the pathogenesis and epidemiology of the disease is not yet fully clarified. Geomyces destructans has been found in Europe but has not been a cause of mass mortality there. This study is the first investigation done to see if G. destructans is present in Sweden.

Data retrieved from airborne laser scanning represents a new source of forest data. Today, the technology has matured so that it can function in an operational environment. The aim of this study was to compile areas of application of laserdata in forestry. Moreover to analyze costs and accessibility of laserdata. The goal was to provide private forest owners information to support assessments of possible benefits of laserdata.

Allanblackia is a tree genus native to humid forests in West, Central and East Africa. Its fruits contain large seeds from which edible high-quality fat can be extracted. In order to create a sustainable supply chain of Allanblackia seeds, a domestication program has been initiated with the purpose to enable smallholder farmers to grow the tree as an agroforestry component and cash crop. More knowledge is required to understand the tree?s biology and possible symbioses involving soil microorganisms with plant growth enhancing poten-tial.

The main purpose with this study was to investigate whether the tree growth differs or not in prescribed burnt areas compared to mechanically scarified. Together with the result from the main purpose, answers of whether it's possible or not to combine nature conservation with tree production in prescribed burnt areas was presented. In these areas the regeneration were analyzed to see if there was enough tree plants to comply with the Swedish Forestry Act regulations terms for approved regeneration. A field survey was conducted at 6 objects, three objects for prescribed burning and three for mechanically scarification. All objects were planted within the same year.