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Underröjningsgradens påverkan på förstagallringsnetto med flerträdsaggregat / Effects of pre-commercial thinning with multi-grip harvester on first thinning net valueGunnarsson, Björn January 2015 (has links)
I Sverige finns ca 1,2 miljoner hektar skog som bedöms ha omedelbart röjningsbehov. Skog där röjningen uteblir eller är svag kan komma att klassas som konfliktbestånd. I konfliktbestånd är stammarna många och diameterspridningen stor och dessa kan då behövas underröjas innan gallring. I denna studie jämfördes produktionen, kostnaderna och intäkterna från fyra olika underröjningsbehandlingar, oröjd, siktröjt, röjt allt upp till 5 cm i brösthöjd och röjt allt upp till 7 cm i brösthöjd. Behandlingen oröjd gav det bästa nettot och sämst hade upp till 5 cm efter gallring och uttransport av virke. En anpassad eller svag röjning gav lägre totalkostnader jämfört med ingen eller hårdare röjning. / In Sweden there are about 1,2 million hectares of forest with immediate need of pre-commercial thinning. Stands, where conducted pre-commercial thinning are light or even absent, become tight with thin stems. In such stands pre-commercial thinning before first thinning may be required, due to operational advantages such as increased visibility. This study compared production, cost and revenues from four different pre-commercial thinning treatments: no pre-commercial thinning, sight pre-commercial thinning, cleared everything up to 5 cm diameter at breast height and cleared everything up to 7 cm diameter at breast height. The treatments whit no pre-commercial thinning had best net value and worst had up to 5 cm. A custom or weak pre-commercial thinning give a lower total cost compared to no or harder pre-commercial thinning.
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OPTIMERING AV TRANSPORTFLÖDET FÖR MASSAVED : Minimering av transportkostnader och koldioxidutsläpp för Norra Skogs tåg- och lastbilstransporter / OPTIMIZATION OF TRANSPORT FLOW FOR PULPWOOD : Minimization of transport costs and carbondioxide emissions for Norra Skog’s train and truck transportsHäggström, Hanna, Leonardson, Mimmi January 2024 (has links)
Med fokus på att öka lönsamheten för sina medlemmar strävar Norra Skog ständigt efter att förbättra och effektivisera sin logistik för att hantera det ständigt föränderliga flödet av massaved från skogsavlägg till industri. För att uppnå detta har företaget implementerat Woodflow, en avancerad programvara för logistikoptimering. I linje med det ökande intresset för att minska transportkostnader och främja hållbarhet inom transportnätverket, har det också börjat väcka intresse för att undersöka möjligheterna till att utöka användningen av tågtransporter för massaved. Detta examensarbete syftar till att analysera och optimera Norra Skogs transportflöde av massaved med målet att minimera transportkostnader och undersöka möjligheterna till att minska koldioxidutsläpp inom transportflödet. Arbetet inleddes med en grundlig litteraturstudie för att skapa en förståelse för leveranskedjan för massaved inom skogsindustrin samt ge en bakgrund till den optimeringsteori som ligger till grund för programvaran Woodflow. Genom användning av Woodflow utfördes olika scenarioanalyser för att utvärdera olika strategier och metoder för att optimera transportflödet. Relevanta data för projektet samlades in och bearbetades för att förbereda indata till programvaran och möjliggöra analys av informationen om transportflöden för massaved. De undersökta scenarierna inkluderade ett scenario som speglade det faktiska transportflödet år 2023 och ett scenario med optimerade lastbilstransporter som användes som referenspunkt. Vidare genomfördes ett scenario med fria tåg- och lastbilstransporter med syftet att undersöka det optimala transportflödet som minimerar transportkostnader. Införande av nya terminaler och uteslutande av en befintlig terminal undersöktes i ett scenario och dessutom utfördes en analys av minimering av koldioxidutsläpp och transportkostnader genom att tillämpa en premiekostnad som representerade lastbilstransporternas högre koldioxidutsläpp. Till sist genomfördes ett framtidsscenario som syftar till att undersöka hur Norra Skog bör planera för sina transporter i framtiden utifrån prognoser av ökade tillgångsvolymer. Genom att noggrant utvärdera dessa olika scenarier söker arbetet efter de mest effektiva och hållbara lösningarna för Norra Skogs transportflöde för massaved. Resultatet visar på att det finns potential till stora kostnadsbesparingar och betydande minskningar av koldioxidutsläpp genom att optimera lastbilstransporterna från det faktiska utfallet 2023. Därefter finns ytterligare kostnadsbesparingar att hämta genom att optimera tågflödet och transportera mer volym via detta mer hållbara transportslag. Samtliga optimeringar av tågflödet, förutom framtidsscenariot med ökad tillgång, bidrar till ytterligare minskningar av koldioxidutsläpp och det anses därav vara av intresse för Norra Skog att fortsatt undersöka och utvärdera möjligheten att utöka tågtransporterna. Det är främst terminalen Storuman som visar på stor potential för fler antal tågavgångar, medan Hissmofors och Bastuträsk överlag visar minst potential för utökning av tågtransporter. Vidare visar terminalen Östavall ytterligare potential för ökad transport av massaved via tåg genom att helt ersätta terminalen Ånge. / Focusing on increasing profitability for its members, Norra Skog continuously strives to improve and streamline its logistics to manage the ever-changing flow of pulpwood from forest sites to industry. To achieve this, the company has implemented Woodflow, an advanced logistics optimization software. In line with the growing interest in reducing transportation costs and promoting sustainability within the transport network, there has also been increasing interest in exploring the possibilities of expanding the use of rail transport for pulpwood. This thesis aims to analyze and optimize Norra Skog's transport flow of pulpwood with the goal of minimizing transportation costs and exploring possibilities to reduce carbon dioxide emissions within the transport flow. The work began with a thorough literature review to create an understanding of the supply chain for pulpwood in the forestry industry and then provide a background to the optimization theory underlying the Woodflow software. Using Woodflow, various scenario analyses were conducted to evaluate different strategies and methods for optimizing the transport flow. Relevant data for the project was collected and processed to prepare input for the software and enable the analysis of information on pulpwood transport flows. The scenarios examined included one that reflected the actual transport flow in 2023 and one with optimized truck transports used as a reference point. Furthermore, a scenario with free rail and truck transports was conducted to investigate the optimal transport flow that minimizes transportation costs. The introduction of new terminals and the exclusion of an existing terminal were examined in one scenario, and an analysis of minimizing carbon dioxide emissions and transportation costs was also performed by applying a premium cost representing the higher carbon dioxide emissions of truck transports. Finally, a future scenario was conducted to examine how Norra Skog should plan its transports in the future based on forecasts of increased supply volumes. By carefully evaluating these different scenarios, the work seeks the most efficient and sustainable solutions for Norra Skog's pulpwood transport flow. The results show that there is potential for significant cost savings and substantial reductions in carbon dioxide emissions by optimizing truck transports from the actual outcome in 2023. Further cost savings can be achieved by optimizing the rail flow and transporting more volume with this more sustainable mode of transport. All optimizations of the rail flow, except for the future scenario with increased supply, contribute to further reductions in carbon dioxide emissions and are therefore considered of interest for Norra Skog to continue evaluating the possibility of expanding rail transports. It is mainly the terminal Storuman that shows great potential for an increased number of rail departures, while Hissmofors and Bastuträsk generally show the least potential for the expansion of rail transports. Furthermore, the Östavall terminal shows additional potential for increased transport of pulpwood by rail by completely replacing the Ånge terminal.
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Padrões de diversidade em comunidades de aves relacionadaos a varáveis de habitat em campos temperados do sudeste da América do SulDias, Rafael Antunes January 2013 (has links)
Indivíduos, populações e espécies tendem a usar e selecionar habitats de modo não-aleatório. Consequentemente, a perda e a degradação de habitats geram impactos distintos sobre os organismos dependendo de seus atributos. Os efeitos da perda de habitat são claros – os organismos são eliminados ou desalojados por falta de habitat ou baixo sucesso reprodutivo. As consequências da degradação de habitat são mais sutis, e resultam na incapacidade de um ecossistema sustentar determinadas espécies. Como a perda e a degradação de habitat reduzem a disponibilidade de nichos, espera-se que táxons ecologicamente especializados e com requerimentos estreitos de nicho sejam mais propensos à extinção que generalistas. Organismos que são negativamente afetados por perda e degradação de habitat em geral exibem porte muito grande ou muito pequeno, baixa mobilidade, baixa fecundidade, reduzido recrutamento e estreitos requerimentos de nicho. Campos temperados constituem ambientes particularmente afetados por perda e degradação de habitat. No sudeste da América do Sul, como em muitas outras regiões do planeta, a expansão da agricultura e silvicultura são os principais responsáveis pela perda de habitat campestre. Os remanescentes de vegetação natural são usados para criação de gado, estando sujeitos à degradação pelo sobrepastejo, pisoteio e técnicas de manejo. Avaliar como a perda e degradação de habitat afetam a diversidade de organismos campestres é vital para o desenvolvimento de estratégias de conservação e manejo. A presente tese tem por objetivo investigar como a degradação e perda de habitat induzidas pela pecuária e silvicultura afetam a diversidade e a composição das comunidades de aves. Inicialmente, exploramos as relações entre variáveis de habitat e a composição da comunidade de aves num gradiente de altura da vegetação determinado por pastejo em campos litorâneos do Rio Grande do Sul. Posteriormente, avaliamos como variações no relevo interagem com variáveis de habitat e afetam a diversidade de aves em áreas de pecuária na Campanha gaúcha. Finalmente, avaliamos de que forma a perda de habitat resultante do estabelecimento de plantações industriais de celulose em áreas de campo afeta a composição de comunidades de aves campestres. Nossos resultados demonstram que a degradação de habitat decorrente do manejo de gado em campo nativo afeta a comunidade de aves de forma diferencial. Aves adaptadas a campos ralos ou generalistas tendem a ser beneficiadas pelo pastejo, ao passo que as espécies associadas à vegetação alta e densa são desfavorecidas. As variações na topografia reduzem os impactos da degradação de habitat nos campos. Essas variações interagem com o habitat e afetam de forma diferencial os distintos componentes da diversidade. Por outro lado, a perda de habitat decorrente da silvicultura gera um impacto de maior magnitude, alterando a composição das comunidades de aves e favorecendo aves não-campestres. Nesse contexto, impedir que novas áreas de campo nativo sejam convertidas em plantações de árvores passa a ser imperativo. Embora o manejo do gado aumente a diversidade em nível de paisagem ao criar um mosaico de manchas de vegetação de alturas distintas, maior atenção deve ser dada à manutenção e recuperação de formações densas de herbáceas de grande porte. Isso somente pode ser assegurado através de mudanças no regime do pastejo ou do desenvolvimento de técnicas de manejo alternativas. / Individuals, populations and species tend to select habitats in a non-random way. Consequently, habitat loss and degradation will have different impacts on organisms according to their traits. The effects of habitat loss are straightforward – organisms are eliminated or displaced because of the inexistence of adequate habitat or of low breeding success. Effects of habitat degradation are more subtle and result in the reduction of the capacity of an ecosystem to support some subsets of species. Since habitat loss and degradation reduce niche availability, ecologically specialized taxa with narrow niche requirements are expected to be more extinction prone than habitat generalists. Temperate grasslands have been strongly impacted by habitat loss and degradation. In southeastern South America, the expansion of agriculture and industrial pulpwood plantations are the main sources of habitat loss. Remnants of natural grassland vegetation are used for livestock ranching, being subject to habitat degradation from overgrazing, trampling and inadequate management techniques. The evaluation of how habitat loss and degradation affect the diversity of grassland organisms is vital for the development of management and conservation techniques. The main goal of this thesis is to evaluate how habitat degradation and loss related to cattle ranching and pulpwood plantations affect the diversity and composition of bird communities. We began by exploring the relationship between habitat variables and the composition of the bird community along a gradient of vegetation height determined by grazing in coastal grasslands of the state of Rio Grande do Sul. We then assessed how variations in the relief interact with habitat variables e affect the diversity of birds in rangelands of the Campanha gaúcha. Finally, we evaluated how habitat loss related with grassland afforestation for pulpwood plantations affects the composition of grassland bird communities. Our results demonstrate that habitat degradation resulting from livestock ranching in natural grasslands affects bird communities in a differential way. Birds adapted to stunted grasslands or habitat generalists tend to benefit from grazing, whereas tall-grass specialists are negatively affected. Variations in topography are responsible for reducing the impacts of habitat degradation in grasslands. These variations interact with habitat and have a differential effect on distinct components of diversity. On the other hand, the magnitude of the impact of habitat loss from afforestation is larger, altering the composition of bird communities and favoring a series of non-grassland species. In this sense, protecting remaining grasslands from afforestation is imperative. Although cattle ranching increases diversity at the landscape level by creating a mosaic of vegetation patches of different height, more attention should be given in maintaining and recovering dense formations of tall grassland plants. This can only be achieved by changing grazing regimes or developing alternative management techniques.
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The political ecology of the Japanese paper industryPenna, Ian Unknown Date (has links)
The Japanese paper and paperboard industry has grown to be one of the largest in the world. It manufactures a range of products for sale primarily within Japan, and consumes organic fibre for these products from dispersed domestic and foreign forests, plantations and cities. This dissertation examines the links between the development and structure of the industry and its use of papermaking fibre. It takes a political ecology perspective and uses an industrial structure/consumption-production chain approach to show how the industry’s development and structure continue to depend on company control over fibre flows and the restructuring of products, product distribution and manufacture, the fibre supply chain and fibre resources. As with the modern global paper/board industry, the recent growth of the Japanese industry has been characterised by cycles of capacity expansion, market collapse, excess capacity and low prices and profits. Manufacturers and general trading companies involved in the industry have tried to support growth in the use of paper/board and counter these cycles by restructuring production, distribution, ownership and fibre supply. This restructuring helps protect the flow of fibre through the industry and concentrated it in particular companies. Obtaining increasing quantities of suitably-priced fibre has been at the base of the industry’s development.
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The political ecology of the Japanese paper industryPenna, Ian Unknown Date (has links)
The Japanese paper and paperboard industry has grown to be one of the largest in the world. It manufactures a range of products for sale primarily within Japan, and consumes organic fibre for these products from dispersed domestic and foreign forests, plantations and cities. This dissertation examines the links between the development and structure of the industry and its use of papermaking fibre. It takes a political ecology perspective and uses an industrial structure/consumption-production chain approach to show how the industry’s development and structure continue to depend on company control over fibre flows and the restructuring of products, product distribution and manufacture, the fibre supply chain and fibre resources. As with the modern global paper/board industry, the recent growth of the Japanese industry has been characterised by cycles of capacity expansion, market collapse, excess capacity and low prices and profits. Manufacturers and general trading companies involved in the industry have tried to support growth in the use of paper/board and counter these cycles by restructuring production, distribution, ownership and fibre supply. This restructuring helps protect the flow of fibre through the industry and concentrated it in particular companies. Obtaining increasing quantities of suitably-priced fibre has been at the base of the industry’s development.
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Padrões de diversidade em comunidades de aves relacionadaos a varáveis de habitat em campos temperados do sudeste da América do SulDias, Rafael Antunes January 2013 (has links)
Indivíduos, populações e espécies tendem a usar e selecionar habitats de modo não-aleatório. Consequentemente, a perda e a degradação de habitats geram impactos distintos sobre os organismos dependendo de seus atributos. Os efeitos da perda de habitat são claros – os organismos são eliminados ou desalojados por falta de habitat ou baixo sucesso reprodutivo. As consequências da degradação de habitat são mais sutis, e resultam na incapacidade de um ecossistema sustentar determinadas espécies. Como a perda e a degradação de habitat reduzem a disponibilidade de nichos, espera-se que táxons ecologicamente especializados e com requerimentos estreitos de nicho sejam mais propensos à extinção que generalistas. Organismos que são negativamente afetados por perda e degradação de habitat em geral exibem porte muito grande ou muito pequeno, baixa mobilidade, baixa fecundidade, reduzido recrutamento e estreitos requerimentos de nicho. Campos temperados constituem ambientes particularmente afetados por perda e degradação de habitat. No sudeste da América do Sul, como em muitas outras regiões do planeta, a expansão da agricultura e silvicultura são os principais responsáveis pela perda de habitat campestre. Os remanescentes de vegetação natural são usados para criação de gado, estando sujeitos à degradação pelo sobrepastejo, pisoteio e técnicas de manejo. Avaliar como a perda e degradação de habitat afetam a diversidade de organismos campestres é vital para o desenvolvimento de estratégias de conservação e manejo. A presente tese tem por objetivo investigar como a degradação e perda de habitat induzidas pela pecuária e silvicultura afetam a diversidade e a composição das comunidades de aves. Inicialmente, exploramos as relações entre variáveis de habitat e a composição da comunidade de aves num gradiente de altura da vegetação determinado por pastejo em campos litorâneos do Rio Grande do Sul. Posteriormente, avaliamos como variações no relevo interagem com variáveis de habitat e afetam a diversidade de aves em áreas de pecuária na Campanha gaúcha. Finalmente, avaliamos de que forma a perda de habitat resultante do estabelecimento de plantações industriais de celulose em áreas de campo afeta a composição de comunidades de aves campestres. Nossos resultados demonstram que a degradação de habitat decorrente do manejo de gado em campo nativo afeta a comunidade de aves de forma diferencial. Aves adaptadas a campos ralos ou generalistas tendem a ser beneficiadas pelo pastejo, ao passo que as espécies associadas à vegetação alta e densa são desfavorecidas. As variações na topografia reduzem os impactos da degradação de habitat nos campos. Essas variações interagem com o habitat e afetam de forma diferencial os distintos componentes da diversidade. Por outro lado, a perda de habitat decorrente da silvicultura gera um impacto de maior magnitude, alterando a composição das comunidades de aves e favorecendo aves não-campestres. Nesse contexto, impedir que novas áreas de campo nativo sejam convertidas em plantações de árvores passa a ser imperativo. Embora o manejo do gado aumente a diversidade em nível de paisagem ao criar um mosaico de manchas de vegetação de alturas distintas, maior atenção deve ser dada à manutenção e recuperação de formações densas de herbáceas de grande porte. Isso somente pode ser assegurado através de mudanças no regime do pastejo ou do desenvolvimento de técnicas de manejo alternativas. / Individuals, populations and species tend to select habitats in a non-random way. Consequently, habitat loss and degradation will have different impacts on organisms according to their traits. The effects of habitat loss are straightforward – organisms are eliminated or displaced because of the inexistence of adequate habitat or of low breeding success. Effects of habitat degradation are more subtle and result in the reduction of the capacity of an ecosystem to support some subsets of species. Since habitat loss and degradation reduce niche availability, ecologically specialized taxa with narrow niche requirements are expected to be more extinction prone than habitat generalists. Temperate grasslands have been strongly impacted by habitat loss and degradation. In southeastern South America, the expansion of agriculture and industrial pulpwood plantations are the main sources of habitat loss. Remnants of natural grassland vegetation are used for livestock ranching, being subject to habitat degradation from overgrazing, trampling and inadequate management techniques. The evaluation of how habitat loss and degradation affect the diversity of grassland organisms is vital for the development of management and conservation techniques. The main goal of this thesis is to evaluate how habitat degradation and loss related to cattle ranching and pulpwood plantations affect the diversity and composition of bird communities. We began by exploring the relationship between habitat variables and the composition of the bird community along a gradient of vegetation height determined by grazing in coastal grasslands of the state of Rio Grande do Sul. We then assessed how variations in the relief interact with habitat variables e affect the diversity of birds in rangelands of the Campanha gaúcha. Finally, we evaluated how habitat loss related with grassland afforestation for pulpwood plantations affects the composition of grassland bird communities. Our results demonstrate that habitat degradation resulting from livestock ranching in natural grasslands affects bird communities in a differential way. Birds adapted to stunted grasslands or habitat generalists tend to benefit from grazing, whereas tall-grass specialists are negatively affected. Variations in topography are responsible for reducing the impacts of habitat degradation in grasslands. These variations interact with habitat and have a differential effect on distinct components of diversity. On the other hand, the magnitude of the impact of habitat loss from afforestation is larger, altering the composition of bird communities and favoring a series of non-grassland species. In this sense, protecting remaining grasslands from afforestation is imperative. Although cattle ranching increases diversity at the landscape level by creating a mosaic of vegetation patches of different height, more attention should be given in maintaining and recovering dense formations of tall grassland plants. This can only be achieved by changing grazing regimes or developing alternative management techniques.
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Padrões de diversidade em comunidades de aves relacionadaos a varáveis de habitat em campos temperados do sudeste da América do SulDias, Rafael Antunes January 2013 (has links)
Indivíduos, populações e espécies tendem a usar e selecionar habitats de modo não-aleatório. Consequentemente, a perda e a degradação de habitats geram impactos distintos sobre os organismos dependendo de seus atributos. Os efeitos da perda de habitat são claros – os organismos são eliminados ou desalojados por falta de habitat ou baixo sucesso reprodutivo. As consequências da degradação de habitat são mais sutis, e resultam na incapacidade de um ecossistema sustentar determinadas espécies. Como a perda e a degradação de habitat reduzem a disponibilidade de nichos, espera-se que táxons ecologicamente especializados e com requerimentos estreitos de nicho sejam mais propensos à extinção que generalistas. Organismos que são negativamente afetados por perda e degradação de habitat em geral exibem porte muito grande ou muito pequeno, baixa mobilidade, baixa fecundidade, reduzido recrutamento e estreitos requerimentos de nicho. Campos temperados constituem ambientes particularmente afetados por perda e degradação de habitat. No sudeste da América do Sul, como em muitas outras regiões do planeta, a expansão da agricultura e silvicultura são os principais responsáveis pela perda de habitat campestre. Os remanescentes de vegetação natural são usados para criação de gado, estando sujeitos à degradação pelo sobrepastejo, pisoteio e técnicas de manejo. Avaliar como a perda e degradação de habitat afetam a diversidade de organismos campestres é vital para o desenvolvimento de estratégias de conservação e manejo. A presente tese tem por objetivo investigar como a degradação e perda de habitat induzidas pela pecuária e silvicultura afetam a diversidade e a composição das comunidades de aves. Inicialmente, exploramos as relações entre variáveis de habitat e a composição da comunidade de aves num gradiente de altura da vegetação determinado por pastejo em campos litorâneos do Rio Grande do Sul. Posteriormente, avaliamos como variações no relevo interagem com variáveis de habitat e afetam a diversidade de aves em áreas de pecuária na Campanha gaúcha. Finalmente, avaliamos de que forma a perda de habitat resultante do estabelecimento de plantações industriais de celulose em áreas de campo afeta a composição de comunidades de aves campestres. Nossos resultados demonstram que a degradação de habitat decorrente do manejo de gado em campo nativo afeta a comunidade de aves de forma diferencial. Aves adaptadas a campos ralos ou generalistas tendem a ser beneficiadas pelo pastejo, ao passo que as espécies associadas à vegetação alta e densa são desfavorecidas. As variações na topografia reduzem os impactos da degradação de habitat nos campos. Essas variações interagem com o habitat e afetam de forma diferencial os distintos componentes da diversidade. Por outro lado, a perda de habitat decorrente da silvicultura gera um impacto de maior magnitude, alterando a composição das comunidades de aves e favorecendo aves não-campestres. Nesse contexto, impedir que novas áreas de campo nativo sejam convertidas em plantações de árvores passa a ser imperativo. Embora o manejo do gado aumente a diversidade em nível de paisagem ao criar um mosaico de manchas de vegetação de alturas distintas, maior atenção deve ser dada à manutenção e recuperação de formações densas de herbáceas de grande porte. Isso somente pode ser assegurado através de mudanças no regime do pastejo ou do desenvolvimento de técnicas de manejo alternativas. / Individuals, populations and species tend to select habitats in a non-random way. Consequently, habitat loss and degradation will have different impacts on organisms according to their traits. The effects of habitat loss are straightforward – organisms are eliminated or displaced because of the inexistence of adequate habitat or of low breeding success. Effects of habitat degradation are more subtle and result in the reduction of the capacity of an ecosystem to support some subsets of species. Since habitat loss and degradation reduce niche availability, ecologically specialized taxa with narrow niche requirements are expected to be more extinction prone than habitat generalists. Temperate grasslands have been strongly impacted by habitat loss and degradation. In southeastern South America, the expansion of agriculture and industrial pulpwood plantations are the main sources of habitat loss. Remnants of natural grassland vegetation are used for livestock ranching, being subject to habitat degradation from overgrazing, trampling and inadequate management techniques. The evaluation of how habitat loss and degradation affect the diversity of grassland organisms is vital for the development of management and conservation techniques. The main goal of this thesis is to evaluate how habitat degradation and loss related to cattle ranching and pulpwood plantations affect the diversity and composition of bird communities. We began by exploring the relationship between habitat variables and the composition of the bird community along a gradient of vegetation height determined by grazing in coastal grasslands of the state of Rio Grande do Sul. We then assessed how variations in the relief interact with habitat variables e affect the diversity of birds in rangelands of the Campanha gaúcha. Finally, we evaluated how habitat loss related with grassland afforestation for pulpwood plantations affects the composition of grassland bird communities. Our results demonstrate that habitat degradation resulting from livestock ranching in natural grasslands affects bird communities in a differential way. Birds adapted to stunted grasslands or habitat generalists tend to benefit from grazing, whereas tall-grass specialists are negatively affected. Variations in topography are responsible for reducing the impacts of habitat degradation in grasslands. These variations interact with habitat and have a differential effect on distinct components of diversity. On the other hand, the magnitude of the impact of habitat loss from afforestation is larger, altering the composition of bird communities and favoring a series of non-grassland species. In this sense, protecting remaining grasslands from afforestation is imperative. Although cattle ranching increases diversity at the landscape level by creating a mosaic of vegetation patches of different height, more attention should be given in maintaining and recovering dense formations of tall grassland plants. This can only be achieved by changing grazing regimes or developing alternative management techniques.
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Application of game theory in Swedish raw material market : Investigating the pulpwood marketAl Halabi, Rami January 2020 (has links)
Studien går ut på att analysera marknadsstrukturen för två industriföretag(Holmen och SCA) under antagandet att båda konkurrerar mot varandragenom att köpa rå material samt genom att sälja förädlade produkter.Produktmarknaden som undersöks är pappersmarknaden och antas varakoncentrerad. Rå materialmknaden som undersöks ärmassavedmarknaden och antas karaktäriseras som en duopsony. Detvisade sig att Holmen och SCA köper massaved från en stor mängdskogsägare. Varje företag skapar varje månad en prislista där de bestämmerbud priset föassaved. Priset varierar beroende på region. Både SCA ochHolmen väljer mellan två strategiska beslut, antigen att buda högt pris ellerlågt pris. Genom spelteori så visade det sig att båda industriföretagenanvänder mixade strategier då de i vissa tillfällen budar högt och i andratillfällen budar lågt. Nash jämviktslägen för mixade strategier räknades utmatematiskt och analyserades genom dynamisk spelteori.Marknadskoncentrationen för pappersmarknaden undersöktes viaHerfindahl-Hirschman index (HHI). Porters femkraftsmodell användes föratt analysera industri konkurrensen. Resultatet visade attproduktmarknaden är koncentrerad då HHI testerna gav höga indexvärdenmellan 3100 och 1700. Det existerade dessutom ett Nash jämviktsläge fö mixade strategier som gav SCA förväntad lönsamhet 1651 miljoner kronoroch Holmen 1295 miljoner kronor. Dynamisk spelteori visade att SCA ochHolmens budgivning följer ett mönster och att högt/lågt bud beror påavvikelser från Nash jämviktslägets sannolikhetsdistribution. Nashjämviktslägets råder ifall sannolikhetsdistributionerna vid låg budgivningär 68,6 procent för SCA och 66,7 procent för Holmen. Detta gav indikatore för icke samarbetsvilliga spel. Slutsatsen är att om två spelare (kvarnar) når / The research aims to analyze the market structure of two companies in th forest industry (Holmen and SCA) with the assumption that thes companies compete at buying raw materials and selling products. Theproduct market in this study is the paper market under the assumption thatboth companies operate in a concentrated product market. The rawmatial market that one investigates in this study is the pulpwood marketunder the assumption that it is a duopsony. What this study has concludedis that Holmen and SCA buy pulpwood from lots of different self-managingforest owners. Each company creates a monthly pricelist where they decidethe bid price of pulpwood. The amount varies depending on the region. Bot SCA and Holmen chooses between two strategic decisions, either to bid highor to bid low. Through game theory, it has been clear that each company usesmixed strategies as they sometimes give high bids and sometimes give lowbids. The Nash equilibrium for mixed strategies have been calculatedmathematically and analyzed through the dynamics of game theory. As fore market concentration, the product market has been investigatedthrough the Herfindahl-Hirschman index (HHI). Porter's five-force modelwas used to analyze the industry competition. The results showed that theproduct market is concentrated as the HHI tests gave High index scoresbetween 3100 and 1700. In addition, there existed a Nash equilibrium in amixed strategy that gave SCA expected payoff 1651 million SEK and Holmen1295 million SEK. The dynamic game theory showed that SCA and Holmen'sbidding follows a repeating trajectory and that the high/low bidding is dueto deviations from Nash equilibrium probability distribution. The Nashequilibrium situation prevails if the probability distribution at low biddingis 68.6 percent for SCA and 66,7 percent for Holmen. This providedindicators for a non-cooperative game. The conclusion is that if two players
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