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905 Uppsatser om Forest edges - Sida 30 av 61
Minskad utbredning av apollofjäril, Parnassius apollo, i södra Stockholms län : En studie av möjliga faktorer utifrån artens habitatkrav
The Apollo butterfly, Parnassius apollo, is categorized as Near Threatened (NT) in IUCN Red List. Today in Sweden it is found only in strongly fragmentized populations. In the county of Stockholm, P. apollo exists exclusively in some islands of the archipelago and with one mainland population in Stora Vika. This study has the purpose of expanding the knowledge of the local conditions for the butterfly in the south parts of the county of Stockholm and thereby contributes to a sustainable land management that can preserve the Apollo butterfly.A comparative study was done between areas where the butterfly today have: a stable population (Stora Vika, Utö and Ålö), has disappeared (Muskö and Yxlö) or is strongly declining (north part of Ornö).
Den skogliga informationens roll i ett kundanpassat virkesflöde : en bakgrundsstudie samt simulering av inventeringsmetoders inverkan på noggrannhet i leveransprognoser till sågverk
This MSc thesis is divided into two parts. The first part deals with the need for information
from forest campartments selected for clear cutting, in connection with planning in an
integrated forest- and sawmill enterprise. A review of literature is followed by a case stud y,
where present conditions in a Swedish forest company are compared with current research in
the area. The seeond part consists of a simulation stud y, which aims at camparing the
accuracy of inventory estimates using different methods. The estimates are delivery forecasts,
covering one month consumptian of timber in a large sawmill.
Kan markfuktighetskartor användas för att hitta skogsmark med hög bonitet? : ett gis-baserat försök med dtw-index och laserskannad övre höjd
The depth-to-water-index (DTW-index) is derived from digital elevation models (DEM) to map soil wetness, in terms of distance from soil surface to the ground water table. The aim of this GIS based study was to investigate the existence of a relationship between DTW-index and forest site productivity (SP). The belief of such an assumed relationship was based on knowledge that the ground water level is related to site properties that can either promote or impede tree growth.
Data primarily comprised rasters of the Krycklan catchment in northern Sweden and depicted DTW-index and a laser scanned vegetation height. The 100th height percentile of each pixel in the vegetation raster was assumed to mirror the top-height, letting it act as a relative measure of SP within a delineated area of equal stand age.
Däck-mark Interaktion hos skogsmaskiner
The most predominant method for forest harvesting in Sweden is the cut-to-length method based on two-machines, a harvester that fells trees and cut them in a predefined length, and a forwarder which transports logs to a landing area for further transport to a processing facility. New machine solutions have to be much gentler to the ground than today?s machines. To be able to develop a forestry machine that preserves the terrain requires a proper understanding of the interaction between tire and soil.The goal of the project is to contribute to the existing knowledge of forest machine tire-soil interaction and to develop a tire-soil model that enables dynamic simulations of forest machines operating in rough terrain. The modeling has especially been focused on the interaction between tires and soft ground.A comparison of theoretical data of different WES-based terrain interaction models and a comparison test data from a full scale field test is presented.
Att veta Gudarnas hemlighet : En sårbarhetsanalys av omständigheterna kring stormen Gudrun med pressure and release modellen
The concept of vulnerability is the capacity or the sensitivity to become damaged. Vulnerability are characterized by one or more of the following terms; a system´s sensitivity to exposure to shock, stress or interference, the state of the system in relations to a threshold of damages, and the system´s ability to adapt to the changing circumstances. Vulnerability in this study is referring to the sensitivity of the circumstances that lead to sustainable livelihood that can´t be maintain and that there is an inability to cope with and manage stress. The choice of making a study in this area is based on that action needs to be taken to moderate the vulnerable aspects of society, in this respect in relations to storms. Analyzes of the social vulnerability to climate change or natural events is needed for effective actions.
Vad orsakar skador på kvarstående träd vid mekaniserad gallring - en intervjustudie
This thesis includes a review of scientific studies of tree injuries following mechanized thinning. Interviews have been made with drivers of single grip harvesters and forwarders in forest thinning and a number of essential factors have been identified as the most important to take into account in order to minimize and/orprevent injuries to stems and roots of remaining trees..
Advantages and disadvantages of different observation methods on a troop of wild olive baboons at a river in Southern Kenya
Every observation method has its advantages and disadvantages and a well-adopted method gives more reliable results. Factors affecting the choice of the most appropriate methods for recording foraging behaviours include species, group size, environment, seasons and age. The focus for this study was to determine which method is most appropriate for studying the foraging behaviour of a troop of 89 olive baboons (Papio anubis) living in a riverine forest by the Southern Ewaso Ng'iro River by Lale'enok Resource Centre in Kenya. To determine this, a literature study was carried out to compare methods from monkeys and apes. I found instantaneous sampling was the most common method with intervals of 5 minutes in most cited studies.
Metoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket, efter den senaste skogsvårdslagenMetoder för att undersöka effekterna av naturvårdshänsynen i skogsbruket, efter den senaste skogsvårdslagen.
In 1994 a new Forestry Act was accepted in Sweden. One of the aims of the law is to raise consideration forpreservation of biodiversity. Since the new law got accepted and some time has passed, there now lie someinterest in examining whether the law has been effective towards its purpose. Methods suitable for analysishave been examined during this study. The content of this pilot study is based around five parameters whichcan be used to validate the effects of the new law.
Jämställdhet åt skogen?! En studie som utreder anledningarna till att kvinnorna slutar som skogsinspektorer
The forest owner cooperative has observed difficulties with keeping women as forest advisers/ buyers. This is a problem because the organisation wish to have both men?s and women?s qualifications. The organisation?s purpose in their equality and multiplicity plan is to increase the knowledge and awareness of equality and multiplicity, increase the credibility to the members and customers, and to be well prepared for the future need of qualifications.
The purpose of this paper is to identify if there are any conditions that may limit female employees at this particular service.
Evaluation of an ectomycorrhizal macrofungi as an indicator species of high conservation value pine-heath forests in northern Sweden
Since the 1950s, the development of modern rotation forestry in boreal Fennoscandia has resulted in a severe reduction of older forests, and a high degree of fragmentation among the small patches that remains of old forest. In Sweden, when performing conservation value assessments in order to identify and preserve the remaining forest habitats, the government authorities use to a significant extent a set of indicator species that indicate habitats of high biological conservation value. One species considered to indicate high conservation values in pine-heath forests is the red-listed ectomycorrhizal (EM) macrofungi Sarcodon scabrosus (Fr.) P. Karst. In the present study, the validity of using S.
Härliga hagar och skrämmande skogar : om våra känslor för landskapet och vad de beror på
Do our imaginations of real landscapes get affected by works of art such as paintings, myths and literature? They often give very colourful descriptions in words as well as pictures. Do they actually change our feelings for the landscapes we are in and carry around as images inside?
Close your eyes and take a few deep breaths. Imagine that you are leaning against a wooden fence a mild summer evening.
Är bor nödvändigt vid skogsgödsling i Sverige?
This thesis has been made on behalf of SCA Skog AB to assess the need of boron in Swedishforest fertilization. Boron has been added to Swedish forest fertilizers since the beginning of the1980s. This makes the fertilizers more expensive and therefore has the necessity of boron inSwedish forest fertilization been raised.The Swedish bedrock generally contains small amounts of boron. The boron in the bedrock istightly bound to the mineral tourmaline and mostly unavailable for plants. This leads to that thecontribution of boron to the soil from weathering is very low besides soils with marinesediments.
Val av område och områdesskydd för Natura 2000 med skogshabitat : En jämförande studie av fyra län i Sverige
The Natura 2000 Network is one of the European Unions many tools concerning nature conservation, and is without comparison the premier contribution when it comes to halting the loss of biodiversity. This essay is a case study on how the regional work with the Natura 2000-network has been carried out in four different counties. These counties are Södermanland, Västernorrland, Jämtland and Örebro. They have been compared based on the theoretical concept of sustainable development. This essay describes how the officials in the County Administrations view the regional implementation of Natura 2000 when it comes to the selection of Natura 2000-sites with forest habitats and the creation of an additional protective measure.
Planering av väginvesteringar :
The problems around and the planning of wood flow is some of the most complex issues in the forest-sector. The experience and overview of the single employees is crucial for the possibility of correct tactical and economical decision-making. The increasing demand of savings and shorter reaction-times with greater flexibility in the wood-supply-chain, makes solutions and aids for improved effectiveness in the work and processes according to wood-flow urgent.
Holmen Skog is starting to develop a new forest-road-management-system. The system will facilitate the work according to construction, improvements and updating the standard of roads.
Lönsamhetskalkyl för produktion av gran på markavvattnad och askgödslad myrmark
In Sweden there are about 4 million hectares of bare peat (mire). This land has great potential to be transformed into productive forest land, provided drainage is carried out and, in some cases, even fertilization with ashes. Drainage of mires is necessary because the high groundwater table prevents trees from growing due to reduced oxygen availability. Some of the key nutrients that trees need to grow appear in too small quantities in mires, especially potassium (K) and phosphorus (P). Ash from the combustion of biomass contains these elements and is therefore suitable as a fertilizer.