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949 Uppsatser om Mountain birch forest - Sida 1 av 64
Timmerkvalitet hos björk i blandskog med gran
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).
Härjedalens fjällängar ? en flygbildsstudie över igenväxningen av subalpina ängar
Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Landskapsvårdens hantverk, 15 hp, [2014].
Vinster med björkinblandning i granbestånd i syfte att höja markens pH-värde
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.
Ståndortsanpassning och produktionspotential för björk i Gävleborgs län
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.
Klassning av fjällbjörkskog enligt FAO:s definition av skogsmark med hjälp av flygburen laserskanning
Sweden?s forestry legislation was updated in 2010 and a new definition of forest land was introduced. This definition was adapted to the one used by the Food and Agriculture Organization of the United Nations (FAO) for international statistics on the state of the world's forests. It is in short based on the lands ability to grow forest that reaches 5 meters, 10 % canopy closure and has a continuous distribution, according to FAO at least 0.5 hectares. A country-wide laser scanning is now carried out for the production of a new national elevation model; the laser data also provides information on forest height and density.
Fortsatt gran eller självföryngrad björk efter stormfällning? : en ekonomisk analys
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.
Ett gammalt kulturlandskap i Vindelfjällen : skogshistoria och markutnyttjande i Vuornavagge under 300 år
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.
Fjällfåglar : En jämförande studie från dal till topp i ett nordligt och sydligt svenskt fjäll
Title: Mountain birds ? a comparative study from valley to mountaintop in a northern and southern Swedish fjeld Author: Kristian Zackrisson Abstract Main aim in this study was to increase the knowledge about birds in the Swedish mountain area. Three questions were asked: 1) Which bird species can be found during the breeding season along a low mountain slope from a forested valley to a mountaintop with bare mountain environment? 2) Do the number of species and individuals differ in different elevation zones? 3) Is the composition of bird species along a low mountain slope the same in the Kebnekaise mountains inLaplandand the Grövelsjön mountains in Dalarna? Bird census in two study sites located in the Kebnekaise mountains and the Grövelsjön mountains and subsequent analysis of the results from the bird census was the main parts in this study. Totally 20 bird species were found along a low mountain slope in the Kebnekaise mountains.
Levande fäbodbruk på 2000-talet : -svårigheter respektive möjligheter
Mountain holding in the 21st century ? difficulties and possibilities This study examines the difficulties and possibilities that mountain holding farmers have today. The following questions were considered: i) Who is cultivating mountain holdings today? ii) Which is the most important reason to keep animals there? iii) What kind of subsidies are most common? iv) What kinds of animals and what breeds are the most common? v) For how long period of time are the animals kept at the mountain holdings every season? vi) How are the fundamental regulations in the animal welfare law being followed, and are there any problems/conflicts in keeping animals at the mountain holdings? vii) What meaning do the animals have for the farmers and what are the farmer?s thoughts about the future? A survey based on these issues was sent out to 107 mountain holdings farmers with animals on grazing land, where 59 % submitted a response. The results showed that knowledge on how to keep animals at the mountain holdings was overall good.
Viltets inverkan på vegetationsutvecklingen i en Sydsvensk skogsföryngring :
Herbivore impact on the Swedish forest has under a long time been a common subject of
debate. There are many different opinions depending on what direction the forest owner has with his/her forest. Populations of moose and roe deer have increased significantly in Sweden during the last decades. The purpose of this study is to get a full picture of the herbivore impact on the regeneration areas. The field work was done once a year for seven years (1999?2005).
Hur påverkar naturvårdsåtgärder mängden av vedlevande insekter : Manuellt dödade träd vs självdöda
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.
Bedömning av skada på naturmiljö och rennäring för den föreslagna fjällvägen mellan Borgafjäll och Saxnäs : - Väg- och transportforskningsinstitutets metod för bedömning av skada på bevarandeintressen
Assessment of impacts on nature and reindeer husbandry by the considered mountain road between Borgafjäll and Saxnäs- Swedish National Road and Transport Research Institutes method for assessment of damage to heritage assetsThere are plans regarding the building of a new road from Borgafjäll/Båtas to Saxnäs, and two road alternatives have been presented. The road has been localized to an area which is protected as a nature reserve and listed as a Nature 2000 area. This report aims to determine the effects on the Nature 2000 area and reindeer husbandry, and to be a source of knowledge for future environmental impact assessment in that project. In order to assess the impact on nature values and reindeer husbandry a method from the Swedish National Road and Transport Research Institute (VTI) has been used. A literature review has been made to prescribe the effects and consequences.
Lövskogens förändring i eklandskapet söder om Linköping : 1927 jämfört med 2013
The forests of Sweden are constantly changing. Map studies indicate that the amount of deciduous trees in Sweden has decreased in recent years in favor of the coniferous trees. The National Forest Inventory has since the early 1920s monitored the Swedish forests and in recent years has made the old data digitally available. In the present project, we have investigated how the numbers of stems in different diameter classes have changed for birch and other deciduous trees. The inventory was conducted in the same manner as in the first forest inventory.
Lämplig röjningstidpunkt utifrån björkstubbskottens konkurrens
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..
Uttag av kvalitetsvirke a björk - potential och problem
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.