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3305 Uppsatser om National Forest Inventory - Sida 2 av 221
Analys av linjetaxering i samband med gallringsinventering med avseende på kvalitet, tillförlitlighet och framtida utformning
Modern forest owners are very familiar with forest management and forest economics. Therefore they have high demands for quality in forest operations. Guarantee of quality in the shape of self-checking activities is an important tool to guarantee a well managed forestry operation. To meet the forest owners? demands on guarantee of quality and the entrepreneurs wish of an easy method for self-checking, the forest owners association, Södra skogsägarna, has developed a new method for thinning inventory.
The purpose of this study is to evaluate the method that is used for self-checking and to find ways to develop and improve of the method.
The data has been collected by inventory in a number of stands with circle-area survey and with strip survey, which is method that is used for self-checking.
The results show that the strip survey does not diverge more than ±10 % in measuring values of basal area, number of stems, roads share, thinning quotient, outtake of basal area and total volume compared to circle-area survey.
Naturvärden i en värmländsk bruksskog : en skogshistorisk studie av Åbengtshöjden/Bogranghöjden
In this study I have analysed the history of a forest belonging to Saxåhyttan in Värmland. The study area is 448 hectares and has been used by iron industry since the 16th century. A forest that has been used by man during at least 400 years should have few ecological values. This inventory however shows the opposite.
The aim of the study is to interpret the history of the forest in the area, i. e.
Samband mellan laserdata och fältdata
To make it easier for forestry planning the forest owners needs data which describe characteristics of the forest. Such data you usually get from some type of inventory. A relatively new technology which probably is getting more important in the future, is laser scanning because of lower costs. But because the laser technology is relatively new you need to compare it with conventional inventory technologies to get better understanding of the possibilities the laser technology gives. This work intends to estimate field measured characteristics of the forest from laser data with help of regression analysis and then see which of the field measured properties that best could be estimated and which laser variables that gave the best results.
This study shows that heights has the best estimates, but biomass, diameter and volume also gives good estimates.
Sjunkande pH i Västerbottens humuslager : en kvantitativ analys
Acidification is a central concept in the environmental debate. The effect of acidification of the soil is a matter of a decreasing amount of cations and thereby a decreasing ability to resist a supply of hydrogen ions to the soil. Acidification has gradually increased in the O horizon in Västerbotten over a 30-year period from the 1970th to the 1990th. The aim of this study was from inventories of The Swedish National Forest Soil Survey and The Swedish National Forest Inventory explain and quantify the acidification that has occurred in the O horizon of two regions in the north of Sweden. Data from SMHI, The Swedish Meteorological and Hydrological Institute, has also been used.
Skogens produktionsvärden och dess betydelse för Sveriges ekonomi
The forest is characterized by many different values such as those related to forest productivity which are of a big importance for Swedish economy. History has proved that forest resources had helped the country in the transition from the agricultural to the industrial society. Today Swedish forest industry is among the strongest in Europe and significantly contributing to the Swedish export. The industry provides many direct and indirect job opportunities and is one of the biggest employers in the industry sector. It is also worth to notice that the forest can also generate an additional income for the owners, even if the forestry isn?t their primary income source.
Analys av framtida potential för virkesköp från privata skogsägare i Västerbottens län : beslutsunderlag för virkesköpsstrategier
This study was conducted on behalf of SCA forest AB, Västerbottens forest administration. Timber procurement from non-industrial private forest owners has become an increasingly important part of SCA:s wood supply. The objectives of this study was to report the current forest conditions in the private forests in the county of Västerbotten, analyse the potential for procurement of wood from private forest owners, and provide a basis for decisions on future strategies for timber procurement from private owners.Material and data have been collected from different sources, mainly from Swedish National Forest Inventory and SKA-VB08. This material was the basis for the analysis and calculations performed with the Heureka application PlanWise. This study area was divided into six different analytical areas (Coastal south, Coastal middle, Lycksele, Inland south, Inland north, Skellefteå), where each area of analysis is represented by a number of municipalities.In this study, two scenarios were specified; one describing the current forest management with current harvesting levels and the effects of these assumptions, the second to illuminate what potential there is for future timber harvesting.
Analys av data från flyglaserscanning :
In forestry there are always needs of forest data to make good strategic decisions of different actions and economic winning. Usually this data gets from field-estimations made by forest workers with expensive costs and sometimes unsatisfied quality.
StoraEnso Skog is a great forest company in Sweden and they have part of the responsibility of the forest own by Bergvik Skog. Bergvik Skog is owner of 1, 9 million hectares productive forest land. Both Bergvik and StoraEnso have great interest in new inventory techniques to get the important forest data.
The company Foran Remote Sensing offers the opportunity with airborne laserscanning of forest and forest land. Foran got the mission of Bergvik and StoraEnso to laser scan Bergviks possession in Älvdalen, Dalarna.
Förtolkat digitalt data till skogsägarplan
The purpose of this study is to investigate how to use remote sensing data when making a forest management plan. The main focus of the study is to compare different methods to identify forest stands of a forest property, and by manual measures and estimates try to evaluate the quality of interpreting data.
This report is based on survey questions sent to five different organizations working with remote sensing data. Only two of these where willing to participate in this investigation. The organizations where asked to analyze the same forest property and divide into compartments and make estimations of volume, basal area etc. in every stand.
Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet
Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish National Forest Inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).
Hur kopplad är asp till tidigare jordbruksmark? : en studie av aspförekomst och tidigare markanvändning i fem län i Mellansverige
Aspen (Populus tremula) is a tree that is important for biodiversity. It is a pioneer tree that is favored by much light. It is possible that aspens that regenerated on agricultural land have a different importance for biodiversity than aspens that regenerated in forests, since their conditions have been different. By studying how the land use have changed you can see how many of today?s aspens regeneretad on agricultural land.
Ifrågavarande kronopark skall benämnas Skatan : en skogshistorisk analys av Ekoparken Skatan
People have utilised and influenced the boreal forest for many centuries. Prior to the industrial revolution during the 19th century, however, human use primarily only had a low impact on the forest. When the timberfrontier swept over the country, the Swedish forests came to change for ever. The study site for this thesis is situated in the northern part of the county of Västerbotten, Sweden, and has previously been a National forest. Today the area is an ecopark and the land is owned by the forest company Sveaskog.
Environmental variables determining the occurrence of the red-listed Carbonicola anthracophila and C. myrmecina in boreal forests
The global biodiversity loss is mainly due to human activities such as an intensification of forestry. Boreal forest ecosystems in Fennoscandia are characterized by disturbances such as forest fires, storms and floods. However, industrial forestry practices suppress forest fires and change the landscape, leading to a loss of habitats and associated species. Particularly lichen species with slow adaptation abilities and a strong substrate specificity face an extinction debt in boreal forests since their substrates are long-lived but no longer created. In this study the species-substrate relationship of two red-listed forest-fire dependent lichen species Carbon-icola anthracophila and C.
Föryngring i stormfälld rekreationsskog : en jämförelse mellan föryngring i produktions-, rekreation/produktion och rekreationsskog.
When the storm Gudrun hit Sweden on the 8th and 9th of January, many recreational forests in southern Sweden blew down. For this reason there is a demand for new regeneration methods as to how these storm-felled areas should be regenerated and with what species.
In this study the forest is divided into three areas: production, recreation/production and recreation. The first area is a forest with production as main goal and these kinds of forests are located a bit from the city. The second type ? recreation/production forest ? has two equal goals: production and recreation, and is located close to the city.
Krav och önskemål på skogsbruksplanen : förbättringspotential med laserskanning
In 2009 The National Land Survey of Sweden, Lantmäteriet, commenced a project intended to provide a new digital elevation model (DEM) of Sweden. The method chosen for the project was airborne laser scanning (ALS). In addition to information about the land surface the project will also provide information about the forest, this as a by-product. This data can be used to estimate forest variables such as height and volume. The estimates are often more reliable than what is standard today.
This study is based on interviews with employees and members of the forest owner association Södra in southern Sweden.
Kvalitet på vägdata : inventering av skogsbilvägars standard samt jämförelser med lokal bedömning och SNVDB.
During 2006 SNVDB (the national road data base for forestry) is being introduced to Holmen Skog. This data base contains all information about Holmen Skogs road systems. The information will then be used in different kinds of optimisation models which only produce correct and reliable results if the input data are of the adequate quality.
Today there are reasons to believe that road data is of various qualities. The forest roads are often in a bad condition and have to be improved before a planned harvest. The cost of maintenance and construction of new roads is a large part of the total harvesting cost.