Birch is the dominant deciduous tree species in Sweden but only 16 % is found in pure Birch stands. The majority of the Birch (51 %) is to be found in conifer dominated stands. Swedish forest land comprises approximately of 23 % mixed stands and one problem is that for mixed stands there are few management recommendations. The underlying aim of this thesis was to study the management of mixed forest stands of spruce and Birch to achieve good timber quality of Birch. The study was based on a literature study and measurement in a field experiment launched in 1998 by the Swedish University of Agricultural Sciences (SLU).

Large amounts of Birch-timber are imported to Sweden, from particularly the Baltic States, since the domestic production can?t support the pulp industry. The goal of this study was to show the potential of Birch and the area?s most suitable for Birch production. The study was limited to Gävleborg County. Using site characteristics, site index (SI) for Birch was estimated on all National Forest Inventory plots in Gävleborg County.

The purpose of this report was to investigate if there are any correlation between spruce medium height in young spruce stands and the number of Birch stump shoots. The purpose was also to investigate if there are any correlation between the spruce height growth after clearing and the mean height of Birch stump shoots. The reason for this investigation is that the problem with Birch stump shoots after clearing can be expensive if there must be additional clearings before the first thinning. The study provides no apparent association and therefore no special clearance height is recommended. In the final stages of the work there are given some comments on the study´s weaknesses. Finally topics for further research are suggested..

The purpose of this report is to illustrate potentials and problems with withdrawal of quality timber of Birch. The purpose is also to describe possible ways to increase available quantities of quality timber. Former research is reviewed as introduction. The study begins with a prognosis of future volumes of Birch timber based on consequence analyze by Swedish Forestry Agency. To illustrate the importance of active maintenance, two stands are estimated and simulated in the Heureka module StandWise.

Today?s forest managers implement a large number of methods to increase the amount of dead wood in Swedish forests. They use everything from high cutting of trees to girdling trees and burning forests. However, implementation of these measures without proper knowledge of their consequences is a common problem. This study has been performed to increase knowledge about two of these measures, girdling and high cutting, and how these actions affect the number of wood-living insects living on dead trees.

The southern part of Sweden, Skåne, is frequently exposed to storms causing great damage to Norway spruce (Picea abies L. Karst.) stands. A storm during the winter 1999/2000 raised the attention of the problem. A lot of forest owners got large areas of spruce stands wind thrown during this storm. Can naturally regenerated Birch (Betula sp.) be an alternative on these wind-exposed sites? This was the main question I was facing when discussilig the problems with Esben Möller Madsen, Söderåsens forest district. The aim of this master thesis was to present an economic analysis of Norway spruce versus Birch.

The soil acidification and the pH-value of the soil have been discussed for many years. Many observations of the tree species effects on the soil pH have been done. We have discussed the effects on the soil surface pH-value with a Birch (Betula spp. L.) admixture in Norway spruce stands (Picea abies L.).We have used data from the Swedish National Forest Inventory. We have also discussed how the wood production and the biodiversity can be increased in mixed stands, in according to the Swedish forestry act Skogsvårdslagen. Our sampling areas are located in Norrland, Sweden. The results show a significant correlation between an increased Birch admixture and an increased pH-value of the soil.

After the mandatory rules for clearing was removed in 1994, the clearing area has increased in Sweden. After the storms Gudrun and Per, the areas became planted with new plants, mainly spruce, but also other tree species. Storm areas are now being invaded by naturally rejuvenated Birch in the tilling tracks. Since the Birch often is initially growing faster than the spruce it is inhibiting the growth and is also damaging the spruce. The purpose of this thesis is to study the new brush saw with chain and compare it with the conventional clearing saw, mainly in terms of performance and ergonomics. The results show that the new brush saw with chain is very good in almost all clearing operations compared to the conventional clearing saw.

After the mandatory rules for clearing was removed in 1994, the clearing area has increased in Sweden. After the storms Gudrun and Per, the areas became planted with new plants, mainly spruce, but also other tree species. Storm areas are now being invaded by naturally rejuvenated Birch in the tilling tracks. Since the Birch often is initially growing faster than the spruce it is inhibiting the growth and is also damaging the spruce. The purpose of this thesis is to study the new brush saw with chain and compare it with the conventional clearing saw, mainly in terms of performance and ergonomics. The results show that the new brush saw with chain is very good in almost all clearing operations compared to the conventional clearing saw.

Each year, Heterobasidion spp. is a major cause of economic losses to forestry in the northernhemisphere, including Sweden. New results indicate that pre?commercial thinnings could be at riskfor Heterobasidion spp. infections.

Low stumps represent on their own up to 80% of the dead wood remaining on clear cuts and therefore supply suitable habitat for saproxylic insects i.e. insects depending on dead wood for their survival. Recent stump harvesting activities threaten this substrate of ecological importance and increase the anthropogenic negative impacts on these species. Because of technical and environmental reasons (nutrient leakage, erosion) guidelines for stump harvesting recommend to retain stumps standing in wet parts of clear cuts. However, stumps in wet positions might not be a satisfactory substrate for saproxylic insects and therefore might not be as much used as stumps in dry positions.

Humans have inhabited mountainous areas in northern Sweden since the end of the last glacial period, ca 8000 B.P., and their presence has marked the landscape in various ways. Older traces include the remains of hearths and dwelling sites, but there are also remains, such as culturally modified trees (CMT's), resulting from more recent activities in forested areas. This study aimed to document how people, both indigenous Sami's and Swedish settlers, have used an area northwest of Ammarnäs in Västerbotten, during the last 300 years, and what traces their activities have left in the area. I used historical records as well as an inventory of CMT's in the area to address this aim. Historical records of Sami activity are meagre, but it is clear that the people of the Ran and Gran Sami villages utilized the area long before 1500 A.D.

The purpose of this study was to estimate the removal of biomass in connection with thinning operations in young stands that are dominated by small diameter trees. The economy of such operations depends on the products generated as well as the performance of the harvesting systems. Conversion tables designed to predict the outcome based on harvesting method was another goal of this study. Removal of biomass affects the nutrient composition of the site. Therefore it is a purpose that this study will provide researchers with some variables that can be utilized when studying this aspect. Trees were harvested and divided into bunches based on diameter.

Archaeological findings show that ski manufacturing goes back thousands of years in the Nordic region. There is a wealth of literature and film that deals with the subject, but it can be difficult to get an overall picture of how a specific type of traditional ski has been made. The starting point is the documentary "Skidmakaren i Gielas", where the viewer can follow Alfred Israelsson as he makes a pair of skis out of Birch wood. However, the documentary lacks important information about how the skis are actually manufactured. Length, width and certain working steps are disclosed.

As Birch is one of the most common trees in Sweden, and probably one of the easiest for someone who lives here to identify, it is interesting to note that most people do not know how variable the genus is and how widely it is distributed across the northern hemisphere. One can find Birch growing at both high and low elevations, demanding different soil conditions and preferring varying amounts of sunlight. Many people may also be surprised to hear that the colour of the bark can vary from bight white to almost black, and different shades of pink, orange and red can also be displayed. This, together with the astonishing beauty of the genus, the important role as a pioneer in many ecological systems and the difficulty in sorting out the taxonomy of the genus, constitutes the background of this thesis. The thesis is written at the Department of Landscape Development in Alnarp, Sweden with Kenneth Lorentzon, researcher at the Swedish University of Agriculture as a supervisor. The aim of this thesis is to highlight which species and cultivars within the genus Betula could be appropriate for horticultural use in Sweden.