Urban trees have very little in common with trees on natural sites, such as forests or pastures. Trees in urban environments are often planted in packed soil and in small volumes. This can lead to decreased availability of water and oxygen, as well as deteriorated ability for the soil to store nutritional elements. Also above ground the tree usually have limited space in cities. Regulations on free height over roads and cycle tracks demands high stems at an early stage of their development.

This thesis was conducted at Linköping University and SAAB Aerostructures, Linköping, and focuses on the automation of flexible fixturing in machining applications. At Linköping University a project called "Koofix" is conducted with support from Strategiska stiftelsen and several manufacturing industries including SAAB Aerostructures. The purpose of this project is to develop a more cost-effective, flexible, technique for fixation of workpieces during processing and assembly.Fixtures are an important part during the machining process, especially if you process the parts with high accuracy. Today a large number of fixtures are used at SAAB and they would prefer to reduce the number of fixtures by using flexible fixtures instead. SAAB uses one fixture for each article and this result in a high fixture cost and it also takes time to design and construct a new fixture.There are several advantages with using a flexible fixture such as that you can process workpieces with different length, height and thickness in the same fixture.

Tropical rain forests only cover around six percent of the world?s land area and contain around 70 % of the world´s animals and plants. Tropical rainforests have been, and still are, negatively affected by human activities. These activities lead to forest degradation which has negative impacts on production and biodiversity. Between 1970-1980 forests in Borneo, Sabah, Malaysia, was subjected to intense logging.

The activities of beavers in forested landscapes affect both ecological and economical values. The creation of the dynamic wetland mosaic associated to beaver activities can even improve the quality of water and have been documented as an important landscape engineer affecting the environment for many species. The local office of Sveaskog in Skinnskatteberg is responsible for the management of large areas of the forests in the County of Västmanland. In this area one of several company?s goals are to create ten new wetlands in their own forests as a part of cooperation with the Swedish bird society and Swedish wetland association.

This report investigates the possibility to use non-petroleum based adhesive (biobitumen) in asphalt. The main reasons for replacing bitumen are the fact that oil prices are rising, the threat of peak oil and the fact that the asphalt industry is becoming more environmentally friendly.The main purpose of this report is to investigate whether there are any non-petroleum based adhesives on the market. If so, how can they be used? The questions covered are:? Are there any other alternative asphalt coatings available?? Can bio-oils be used in asphalt?? If the bio-oils can be used, what are the details their properties?? How does a cold climate affect the bio binders?? What is the Swedish asphalt industry?s opinion about bio asphalt?The project was concluded through literature studies, consultations with people in the asphalt industry and through several interviews.The conclusion of this report is that there are some existing non-petroleum based adhesives on the market. They are mainly used for bike paths, sidewalks and parkareas.

The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.

Vida Skog is supplying the whole Vida Ltd?s mills with wood raw material. This study aims to evaluate Vida Skog?s contractors and the relatively new contractorportal and to identify measures that are important for the contractors? skills. The purpose with the portal is to facilitate co-operation between contractors and buyers by streamlining the logistics of the whole wood supply process.The study was conducted in the form of a questionnaire.Most of the respondents were positive to the portal.

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.

This survey was made to investigate the possibility of using an alternative method of fencing inSwedish forestry. The most common way of fencing in Sweden today is made by a two meter highmetal net that is attached to turned impregnated poles. The fencing methods that have beeninvestigated is a fencing system made completely out of wood so called ?German wood fence?.Browsing of game in forest regeneration areas is often a big problem and some kind of protection ofthe plants is often necessary. There is several ways of building fences and the most common way isto use metal nets and impregnated poles, this leads to a problem when the fence has profiled itspurpose.

Different methods for shelterwood cutting have been used in differ-ent parts of Europe since the middle ages. The use of shelter wood cutting in Norway spruce (Picea abies (L.) Karst.) forests in Sweden met a revival in the early 1990s as an alternative for the dominating clear-cutting system when silvicultural costs increased dramatically for the latter. Shelterwood cutting systems involve some possible problems but also a lot of positive effects. Among the problems are increased risk of wind throw and damage of the remaining shelter trees caused by the cutting operation. Positive effects are for example a valuable growth in the remaining trees and increased biological di-versity. This study is based on a total of 79 trees from 4 different treatments in a spruce shelterwood, cut in 1994, in the middle of Sweden (62,4º N).

For a long time the Swedish forests were used by the landowner?s mainly for providing wood to the household itself. The wood was not, to a greater extent, considered a product to be sold. During the 1800s the industrial era led to a demanding need for wood in the industry and thus the use of forest, forest production kicked off. The forest production was not regulated by law, which led to a differentiated forest production over the whole country without consideration of re-growth.

Stump wood was used between 1850 and 1950 for production of tar and as firewood. In the 1950s the use decreased because of the introduction of the cheap fossil oil. In the 1970s stump wood became an interesting issue again as a raw material for the pulp industry. Stump lifting has today become a possible source for bioenergy. The objectives with this study were to investigate the productivity of stump lifting and stump extraction, and to analyse the economy.

The measuring of logs is important in the sawmills process to the sawn products. The technology of automatic wood measurement is continuance developing. This study has the purpose to see how the different techniques and the routines works of measure frames for determining of wood value and sorting in sawmills. The study is performed as a literature study and a survey. The survey includes some of the Swedish sawmills that produce more than 10 000 cubic meters sawed products per year.

This survey was made to investigate the possibility of using an alternative method of fencing inSwedish forestry. The most common way of fencing in Sweden today is made by a two meter highmetal net that is attached to turned impregnated poles. The fencing methods that have beeninvestigated is a fencing system made completely out of wood so called ?German wood fence?.Browsing of game in forest regeneration areas is often a big problem and some kind of protection ofthe plants is often necessary. There is several ways of building fences and the most common way isto use metal nets and impregnated poles, this leads to a problem when the fence has profiled itspurpose.

The Swedish FSC standard (Forest Stewardship Council) is a level standard used to certify forestry. All the major Swedish forest companies are using the FSC standard, and approximately 50% of the Swedish forests are FSC certified today. In the essay six items within the chapter on environmental issues and biodiversity are examined: the proportion of protected forest, the proportion of annually burnt clear-cut stands, the number of trees with large diameter, the amount of dead wood, the proportion of deciduous trees within a stand and the proportion of deciduous-dominated stands. The FSC standard states a level for all items, and the purpose of the essay is to analyse whether these levels are supported by research within the field of conservation biology. The validity of the levels of the six items is them discussed to evaluate whether changes are required to the next revision of the FSC standard.