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467 Uppsatser om Stands - Sida 5 av 32

Rumslig fördelning av grov gammal tall i Uppsala stad med tallticka som indikator på höga naturvärden :

Fragmentation and reduction of forest area is a threat for many forest species and their habitat. Deficiencies in forest quality, such as lack of dead wood and old trees, are one explanation of the threat. The most important action to prevent the continued loss of forest types is to protect forest, but also to restore and to create areas that not previously had high nature values. Hence one of the key strategic roles for Fritid- och Naturkontoret, Uppsala municipality, is to monitor biodiversity in the context of urban planning. The majority of the Uppsala municipality residents live in urban areas and most of them spend some of their spare time in natural areas in cities and their immediate surroundings. Exploitation in and around Uppsala is high, but it is important that there is enough nature close to houses to meet the residents? needs of recreation.

Plantinventering och plantkontroll med digitala bilder från helikopter :

This study was carried out as a commission from Holmen Skog, district ?Egen skog? in Norrköping. During October 2006 several Stands were inventoried by aerial photos from helicopter. The Stands were those for which the next action proposed was plant inventory or plant check. The photos were interpreted and the number of stems was calculated.

Mekaniserad ungskogsbehandling för röjning och skörd :

Earlier attempts at mechanising pre-commercial thinning have been met with varying degrees of success. Most attempts have been based on techniques where residual stems are straddled. Early treatment is essential to limit damage on residual trees. One part of the present study is an evaluation of mechanised pre-commercial thinning using the new Vimek 404R. Vimek 404R is a fairly small machine that permits selective removal of stems, making it potentially suitable also for areas overdue for pre-commercial thinning. The study established the level of performance for the machine, as well as the improvement needed to make it an economically viable option.

Planteringsförbandets inverkan på bildningen av kärnved hos tall (Pinus sylvestris L.) : en modellsimulering av planteringsförbandets inverkan?

The current state of knowledge indicates that there is more than one factor that initiates heartwood transition. This study supports its hypothesis on the theory that heartwood is formed by a fixed fraction of the annual growthring, 0,5 to 0,8 rings. To calculate heartwood volume modelings were carried out in four different pine Stands with different spacings, 0,75, 1,25, 1,5 and three meters. The model indicates heartwood diameter (HWD) and is based on four explanatory variables, height (H), crown ratio (CR%), diameter breast height (DBH) and tree height (TH). The shifting plant spacing results in varying growth rate in the juvenile stage.

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.

Säsongsvis avverkning : det operativa traktvalets påverkan på den säsongsmässiga uthålligheten i ett bolagsdistrikts traktbank

Due to soft grounds in combination with seasonal variation in soil humidity, there is a lack of Stands that are possible to cut during spring and autumn in some geographical regions. For Holmen Skog this sometimes means that a large proportion of the contracted private forest is cut during the winter when the ground is frozen. One consequence of this is that the proportion of winter Stands in the stand bank of own forest increases while spring and autumn Stands becomes a scarcity. This in combination with milder winters, especially when there is a long period of reduced bearing capacity in spring or autumn, means that the situation rapidly can become critical. The overall goal with this study was to generate basic data for decision support in the work to achieve a sustainable distribution between own forest and contracted private forest in the stand bank. The study took place at Holmen Skog, district of Umeå, during autumn 2007 and was based on interviews and an analysis of harvest planning and delivery data. The study showed that there is a problem with how the cutting is distributed between own and contracted private forest during the year and that it foremost is the proportion of winter thinning of own forest that has increased in the stand bank.

Höggallring i praktiskt skogsbruk : beskrivning av en gallringsmodell för granskog som tillämpas på Trolleholms Gods

When Norway spruce is planted with large initial spacing and grows on highly productive sites in southern Sweden, a high proportion of the stems gets broad annual rings. The thinning programme carried out at the estate of Trolleholm aims to extract stems with too broad ring width. The 3-4 first thinnings are carried out as thinning from above, where only the thickest trees are removed. The internal distance may not fall below 5-7 meters depending on the number of thinning (short distance in young Stands). The aim of this study was to examine the thinning model that is carried out at the estate of Trolleholm. A volume table is calculated to describe the model, and data is collected on temporary plots.

Stamräkning och identifiering av åtgärdsbehov i röjnings- och gallringbestånd med hjälp av låghöjdsbilder

This report is an assessment of the feasibility of using aerial photographs to estimate number of stems per hectare in young forest Stands, used together with upper height to determine the need for pre-commercial thinning or ordinary thinning cutting. Aerial photo-interpretation was conducted in 2007 on assignment of Stora Enso Skog AB. A mean height function based on stand age produced with data from Bergvik Skog AB?s 2006 forest inventory assessment was used as a proxy for upper height and used together with photo-interpreted number of stems per hectare to determine the need for thinning cutting according to Bergvik Skog AB?s definitions. The test area is located north of Falun on Bergvik Skog AB?s land.Flight altitude was approximately 900 m above ground and the aerial photos were taken by L&L Flygbildteknik AB.

Stubbehandling med pergamentsvamp och urea mot sporinfektioner av rotticka i bestånd av hybridlärk

Root rot is a big hurter and a huge economic problem for the Swedish and European forestry. The severest hurter is Heterobasidion annosum (Fr.) Bref and it occurs as two different species in Sweden. Commonly referred to as the P-type (Heterobasidion annosum s.s. (Fr.) Bref.) and the S-type (Heterobasidion parviporum Niemelä & Korhonen). Therefore a lot of research has been carried out in this topic to find a solution and reduce this problem, one alternative that have shown to be profitable is stump treatment in thinnings.

Bioenergi från röjningsgallringar : en jämförande studie av fyra flödeskedjor från avlägg till förbrukare

When the Swedish Forestry Act was changed in 1994, brushing of young Stands became non mandatory. Since then the annual need for brushing in the country has increased by about 100 000 hectares per year. In later years the price for biomass energy has increased to the same level as pulp wood. The high price on biomass energy and the large areas of Stands in the need of brushing has created a new market with its own technical, economical and environmental conditions. There is a development of various techniques to manage the forestry Stands with late brushing.

Inventering och klassificering av kvarlämnad virkesvolym vid slutavverkning :

This final thesis is performed on commission of Hargs Bruk Ltd. Hargs Bruk manages one of Sweden?s largest privately owned forests. A main part of the managed forest is situated in Roslagen in eastern Uppland. Since 1934 felling calculations have been performed within the estate every tenth year.

Veto: En motivanalys av FN:s säkerhetsråds fem permanenta medlemmars agerande i konflikten i Syrien.

Aim: The aim of this study is to analyse the possible motives behind the actions of the five permanent members of the UN Security Council in relation to the conflict in Syria. The background of this aim is the Arab Spring and the protests and violence that have followed the uprising. While, in Libya, the UN Security Council adopted resolutions that allowed sanctions against the Libyan government, no such resolutions have been adopted yet in Syria.Theory: The principal theory of the analysis is Stephen D. Krasner´s theory on sovereignty.Method: I have researched various resolutions and statements done in the Security Council, together with official statements from the actors, through Hadenius´ motive analysis methodology and Gilje & Grimen and Ödmans theories on hermeneutics.Conclusion: The conclusion of the analysis is that there, in the case of Syria and Libya, are two different parties in the Security Council. One that Stands for sovereignty and one that Stands for intervention.

Plantering av gran (Picea abies) på kalhyggen och självföryngring under högskärmar av björk (Betula pendula och Betula pubescens) : föryngringsresultat 7-10 år efter avverkning

The aims of the silvicultural method natural regeneration of spruce (Picea abies L. Karst) in birch (Betula pendula and pubescens) shelterwoods are to establish a new stand of tree seedl-ings and to protect those from high groundwater levels, frost damages and grass competition during its first life years. The aim of this work has been to (i) describe how shelterwood and stand characteristics influ-ence the results from using natural regeneration of spruce protected by a shelterwood of birch, and to (ii) compare those regeneration results with planting of spruce after soil scarification in clear-cut areas. Totally 17 harvesting sites have been inventoried and 15 of those included natural regenera-tion in birch shelterwoods, and two were subjects to soil scarification and planting of spruce. The sites represented 7-10 year old final cuts and are located in the coastal (eastern) region of the province of Norrbotten in Sweden. In all areas shelterwood and stand characteristics, as well as the number of main crop seedlings and the height of the highest main crop spruce seedling, were estimated and registered in all areas.

Jämförelse mellan sådd och naturlig föryngring av tall i Härjedalen

The purpose of this study was to compare naturally regenerated Scots pine (Pinus sylvestris (L.)) against seeded Scots pine in terms of benefits and differences. An inventory was performed at a number of different sites, 4 ? 6 years after soil scarification and data on the number of new established plants, their height growth as well as ground-line diameter was collected. Information about site conditions such as altitude, quarter exposure and frost risk was also collected. A review of previous studies was conducted in addition to the field study.

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.

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