Spelling suggestions: "subject:"kontinuitets""
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Skogsbrukets påverkan på artmångfalden hos mossor och lavar : Är artmångfalden större i en skog vid kontinuitetsskogsbruk än vid trakthyggesbruk?Leverin, Malin January 2014 (has links)
Sveriges vanligaste skogsbruksmetod, trakthyggesbruket, har medfört problem för skogens artmångfald. År 2010 fanns det i Sverige 319 stycken hotade mossor och lavar som var kopplade till skogen. Varav vissa arter är beroende av lång skoglig kontinuitet, gammal multnande ved, skogsbrand eller andra naturliga fenomen som enbart finns i en mer eller mindre orörd skog. Alternativet till denna skogsbruksmetod finns i kontinuitetsskogsbruket som var vanligt förr, innan skogsbruket blev till en industri. På den tiden då bönderna själva plockade ut det virke dom behövde för sin egen överlevnad kunde skogen fortfarande fungera som ett ekosystem. Denna rapport avser jämföra och redogöra för eventuella skillnader i artmångfalden av mossor och lavar mellan de tre skogstyperna naturskog, kontinuitetsbrukad och trakthyggesbrukad skog. Undersökningen har baserats på fyra olika kontinuitetsbrukade skogar i Skåne, Västra Götaland och Östergötlands län. Utifrån dessa skogars förutsättningar har sedan trakthyggesbrukade skogar och naturskogar valts ut i acceptabel närhet. Resultatet av undersökningen visar att de trakthyggesbrukade skogarna avviker signifikant i artmångfald från de andra skogstyperna. Naturskogarna och de kontinuitetsbrukade skogarna är rikare i artmångfald och har mer kongruenta värden, dock är förekomsten av epifyter högre i naturskogen. Resultatet visar också att förekomsten av signalarter är högre i en skog vid kontinuitetsskogsbruk än vid trakthyggesbruk. / The most common forestry model in Sweden, the clear cutting forestry, has caused problems for the biodiversity in the forests. In 2010, Sweden had 319 different bryophytes and lichens in the Red List that were connected to the forest. Some of which are dependant of forest continuity, old decaying wood, forest fire or other natural phenomenon found only in more or less undisturbed forests. The alternative to this forestry model is the continuous cover forestry as was common in the past, before forestry became an industry. At the time when the farmers themselves plucked out the wood they needed for they own survival, the forests could still function as an ecosystem. This report aims to compare and account for possible differences in species diversity between the tree forest type natural forest, continuous cover managed and clear-cutting managed forest. This study was based on four different continuous cover managed forests in Skåne, Västra Götaland and Östergötland County. Based on these forests prerequisites, natural forests and clear-cutting managed forests have been selected in acceptable closeness. The results of the survey show that the clear-cutting managed forests differ significant in biodiversity from the other forest types. Natural forests and continuous cover managed forests are richer in biodiversity and have more congruent values, however the presence of epiphytes is higher in natural forests. The result also shows that the presence of indicator species is higher in a continuous cover managed forest than in a clear-cutting managed forest.
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Naturkultur för bättre kvalitet i rotstocken i tallungskog? : Utvärdering av röjningsförsök i KråkerödjanAndersson, Matilda January 2018 (has links)
Scots pine (Pinus sylvestris L.) form a large part of Swedish forestry and has many alternative end-use areas with different requirements for quality. The ability to influence the quality is high in the initial planting and juvenile forest phase, as studies have shown relationships between good quality and dense planting, where competition between trees has a good impact on timber quality. Competition can also be achieved by shading from above, through seed trees or multi-layered forest. Interest in continuous cover forestry grows, and investigating differences in future timber quality between layered and clear cutting treatments can therefore be valuable. Such a method is “Naturkultur”, which aims to optimize the net present value at every point in the forest. The purpose of this study is to highlight the question of whether layered forests methods similar to “Naturkultur” can be used for higher timber quality in pine forests in a cleaning trial in southern Östergötland, Sweden. The goal is to find out if any difference in timber quality exists in the future butt log between the different cleaning treatments, layered (Uneven) and conventional (Even). The survey was limited to studying only the Kråkerödjan pre-commercial thinning trial, located on the property Kråkerödjan between Småland and Östergötland. Parameters for quality estimation were delimited to knot quantity and knot thickness. In order to answer the purpose, a field survey was conducted with quantitative assumptions where data about stem quantity, tree species distribution, height, diameter, height of the living crown, number of knots and diameter for the thickest knot from the base of the trunk up to 2 m on the trunk were collected. The result showed that the number of stems per ha was significantly higher in Uneven than in Even while the volume was next to the same. The average diameter was about 4 cm in Uneven and about 10 cm in Even. The tree species distribution was the same for trees with a diameter > 5 cm a breast height (bh) in both parcels,> 95% pine. For trees <5 cm bh, the distribution in Uneven was 14 % pine, 10 % spruce and 76 % deciduous, in Even there were almost exclusively deciduous trees. When examining pine > 5 cm at bh, there was a significant difference in the knot quantity with fewer knots/m in Uneven than in Even. The thickest knot was smaller in Uneven than in Even, but the difference was only significant when the data without dominants was examined. The thickest knot was slightly smaller relative to the diameter of the trunk in bh in Uneven but the difference was not significant. The average diameter in pine > 5 cm at bh was slightly less in Uneven, 10.7 cm, than in Even, 10.8 cm. The survey gives an indication that the layered forest according to the method of “Naturkultur” in the parcel Uneven, where dominants shades smaller trees, may be used for a better timber quality in pine in the investigated premises. However, the results are not sufficiently clear, if this is due to the fact that the quality difference is small or if it is because quality differences have not yet occurred V cannot be read in the survey. Estimating timber quality early in the rotation period is difficult as a lot can happen until final felling. However, the survey has been valuable as more data is needed in the area in question. Follow-up of the survey is needed to further explore the relationships between stock treatments and quality development.
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Lönsamhet i privat skogsbruk med olika skötselsystem / Profitability in private forestry using different management systems.Dahlberg, Carolina, Larsson, Johan January 2024 (has links)
Det här arbetet har med hjälp av en litteraturstudie och en skötselsimulering i Heureka visat att plockhuggning kan innebära ökad, minskad eller lika god ekonomisk lönsamhet som trakthyggesbruk, mätt i nuvärde. Vilken skötsel som resulterar i högst nuvärde beror på när i omloppstiden jämförelsen görs, skogens tillstånd och vilken kalkylränta som används. Det är ekonomiskt fösvarbart att välja plockhuggning då ett skogsbestånd har hög potential för värdetillväxt, framför allt gallringsskog. I skogar med jämn diameterfördelning och grov medelstam är däremot trakthyggesbruk det enda ekonomiskt rationella alternativet. Bäst ekonomi i plockhuggning fås när stamval görs utifrån måldiameter. Urvalet kan ytterligare förfinas genom att inkludera konkurrens, stamkvalitet och grönkronas storlek. Trakthyggesbruket möjliggör högre medeltillväxt men innebär också större risker. Sammantaget verkar det inte finnas någon anledning att av ekonomiska skäl avråda från vare sig trakthyggesbruk eller plockhuggning. Utgångspunkten vid skoglig rådgivning bör i stället vara skogsägarens mål och skogens förutsättningar.
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Tillväxtreaktioner efter gallring på försöksytor med olika täthet i Östergötland / Growth reaction after thinning in plots of various density in ÖstergötlandHammarstedt, Kaisa January 2018 (has links)
Since the 1950-ies, the dominating silvicultural system in Sweden has included establishment and management of even-aged stands, including final felling. Alternative systems such as continuous cover forestry are increasingly catching interest due the lower impact on stand structure and biodiversity advantages for shade-tolerant species. However it is unknown especially to southern Sweden how trees in a continuous cover forestry system react to common silvicultural measures such as thinning. Therefore the effect of different levels of thinning on the radial growth of larger trees was measured and compared to the ingrowth and proportion of live crown at a site in Östergötland. Unlike previous findings the radial growth was higher in the treatment that had been slightly thinned than in the one that had been heavily thinned. The ability to react with increased radial growth after thinning was not depending on the thinning regime but on the tree’s reaction to a previous thinning. Only trees that had not reacted to the previous thinning increased in radial growth. The radial growth varied more within a treatment than between treatments, which points at the difficulty to allocate growth to specific trees.
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Sustainable Forestry? : A Sustainability Analysis of the Swedish Forest Sector Applying 'Backcasting from Sustainability Principles' as the Methodology / Hållbart Skogsbruk? : En hållbarhetsanalys av den svenska skogssektorn med ”backcasting från hållbarhetsprinciper” som metodRonge, Victoria January 2017 (has links)
Forests are key providers of terrestrial ecosystem services such as climate regulation, water purification, natural pest control, habitats for biodiversity, as well as different forms of wood based materials and food. Nevertheless forests are dangerously exposed to great pressures from various kinds of societal activities. This report examines the importance of forests for the (i) maintenance of life supporting functions of the biosphere as well as for (ii) providing a flexible resource base for the satisfying of human needs on more and more sustainability-driven markets. How can Swedish forestry be managed such that those two essential roles of forests become mutually supportive? The report also relates the results to three relevant and well-citied protocols for the subject: the Sustainable Development Goals in UN’s Agenda 2030, the Swedish Environmental Quality Objectives, and the Swedish National Forest Program. The approach applied Maxwell’s process design for qualitative research. Data have been collected from literature search and interviews of experts and the analytical instrument for modeling of data was the Framework for Strategic Sustainable Development (FSSD). The report concludes: Sustainable development for forestry relies on a paradigm shift in civilization’s perception of forestry to a practice where planning departures from envisioning a future where natural forest functions to sustain higher life forms and civilization are safeguarded and prioritized before other usages of forestland, and where diversity is enhanced in terms of tree age and species to foster more resilient and high-quality timber forests. When the above points are achieved, the higher diversity of more resilient forests should also have potential to supply markets with various kinds of resources offered to more and more sustainability driven markets. Furthermore, this development of society’s forest use increases the chances for civilization to be sustainable also with relatively smaller forest areas put aside for no forestry at all. In such a situation forestry and society have prioritized forest products and usages with long life spans before such with short. A future sustainable Swedish forest sector has recognized the above, and drawn an essential conclusion from it: the interdependency of forests with society’s overall sustainability performance calls for a cooperative approach that departures from an understanding of basic sustainability principles that are shared across sectors and disciplines. The Sustainable Development Goals, the Swedish Environmental Objectives and the Swedish National Forest Program all fail to take the above broad- systems perspective when it comes to proposing measures for the future, including how to advise further research to explore what the sustainable Swedish forestry could entail. The study arrives at pointing out an overall approach to analyses, planning and further research in those regards, rather than evaluating details on the path towards sustainable forestry. / Skogen är en nyckelresurs i den landbaserade naturen som förser samhället med ekosystemtjänster såsom klimatreglering, vattenrening, naturlig skadedjursbekämpning, habitat för biologisk mångfald, likväl som olika former av träfiberbaserade material och mat. Samtidigt är skogen hotad av kraftigt tryck från olika aktiviteter i samhället. Den här rapporten undersöker skogens betydelse för (i) upprätthållande av biosfärens livsuppehållande funktioner, samt som (ii) flexibel resurs när det gäller att förse mänskliga behov på alltmer hållbarhetsdrivna marknader. Hur bör skogen skötas så att dessa två roller stödjer varandra? Rapporten relaterar också resultaten till tre relevanta och vanligt citerade protokoll: hållbarhetsmålen i FNs Agenda 2030, de svenska miljömålen och det svenska nationella skogsprogrammet. Forskningen har strukturerats med hjälp av Maxwells process-design för kvalitativ forskning. Data har samlats in genom litteraturstudier och från intervjuer med experter. Modellering av data har gjorts genom att använda ramverket för strategisk hållbar utveckling (FSSD) som analysinstrument. Rapporten kommer fram till att: Hållbar utveckling för skogsbruket är beroende av ett paradigmskifte. En skogsskötsel där (i) planering utgår från att föreställa sig en framtid där skogens funktioner för högre liv på jorden är säkrade och satta före annan användning av skogsmark, och (ii) mångfald är främjad gällande trädens ålder och antalet arter så att mer resilienta skogar kan bidra med högkvalitativt timmer. När skogen förvaltas på det sättet så bör de mer diversa och resilienta skogarna ha möjlighet att förse marknader med olika resurser som kan visa sig vara viktiga på alltmer hållbarhetsdrivna marknader. Vidare borde denna utveckling av samhälles skogsanvändning öka chanserna för civilisationen att bli hållbar med relativt mindre ytor reserverade för att skyddas mot skogsbruk. Med en sådan förvaltning har skogsägare och samhället i stort prioriterat produkter och användningsområden med långa livslängder före sådana med korta livslängder. En framtida hållbar svensk skogssektor har insett allt ovanstående och dragit en väsentlig slutsats från det: beroendet mellan skogen och samhällets övergripande hållbarhetsarbete kräver samarbete utgående från grundläggande hållbarhetsprinciper som delas över sektors- och disciplingränser. Hållbarhetsmålen i Agenda 2030, de svenska miljömålen och det svenska nationella skogsprogrammet saknas alla ett tillräckligt brett systemperspektiv när det gäller att föreslå åtgärder för framtiden, inklusive att ge rekommendationer för framtida forskning om hållbart svenskt skogsbruk. Studien pekar snarare ut en övergripande inriktning för analyser, planering och forskning om hållbart svenskt skogsbruk, än utvärderar de exakta stegen på vägen dit.
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