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116 Uppsatser om Regeneration - Sida 4 av 8

Kvalitetskontroll av trafikmätningssystem ? En studie om noggrannheten hos induktiv slinga, slang, KomFram, video och radar i olika trafikmiljöer

This report is a study in voltagelevel in connection with Regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during Regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

Restoring biodiversity in degraded secondary rain forest in Sabah, Malaysia : natural regeneration of trees after restoration treatments

Many tropical rain forests has been lost or degraded as a result of human activities and environmental factors. Since the level of biodiversity is high in the tropics, maintaining these areas is of great importance. Forests like these are often assumed to benefit from forest restoration and rehabilitation. The INIKEA project area in Eastern Sabah, Malaysian Borneo, aims to improve biodiversity and/or species richness in the degraded forest through enrichment planting with indigenous species. The objective of this thesis was to evaluate how different treatments (liberation, gap-cluster planting and line planting) affect the biodiversity of natural Regeneration in different forest types in the Rain forest Restoration Experiment, located in the INIKEA project area.

GIS-program för ruttplanering. En studie av nyttjandet av GIS-program för ruttplanering inom tekniska förvaltningar bland kommunder i västra Sverige

This report is a study in voltagelevel in connection with Regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during Regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

Freshwater pearl mussel as indicators of Swedish streams - a comparison between freshwater pearl mussel and biological quality elements

The freshwater pearl mussel (Margaritifera margaritifera) is a large freshwater mussel. Because of its sensitivity to human impact, such as eutrophication, acidification and alterations of hydromorphology, the species is considered as a robust indicator of stream water quality and biodiversity. Moreover, due to the species complex life cycle, including a larval stage on the gills of salmon and trout, and sensitivity of early life stages, Regeneration is often used as an indicator. The freshwater pearl mussel is also used in the expert judgement of status classification of benthic invertebrates according to the European Water Framework Directive. The purpose of this study was to gain a deeper understanding of the freshwater pearl mussel as an indicator for Swedish streams. It was made with two types of association analyses.

Bok- och grankonkurrens i Sydsverige - markegenskaper och naturlig föryngring :

In southern Sweden, beech (Fagus silvatica) and spruce (Picea abies) are two species with similar demands on soil properties. With increased global warming and high acid deposition the future may bring larger areas were the two species are overlapping, competing for the same soil. The aim of this study was to compare spruce and beech concerning distribution, cultivation and soil properties. From available data comparisons were made between spruce and beech forests in Sweden. Soil analyses were made on samples from beech forest in southern Sweden, with and without natural Regeneration of spruce.

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.

Föryngring och produktion av skog på torvmark

Kunskapen kring svensk torvmarksbeskogning är undermålig. En kunskapslucka som till stor del beror på att torvmark tidigare bedömts som ointressant mark i samband med skogsproduktion. Detta beror mycket på det svenska regelverkets restriktioner mot markavvattning och gödsling samt miljöaspekterna som berörs och den aktivare skötsel som krävs. Det ökade behovet av skogsråvara gör att skogsbruket söker nya marker där torvmarken har potential att etableras för skogsproduktion.Studien är en kunskapssammanställning som lyfter fram kunskap kring skogsbruk på svensk torvmark med fokus på föryngringsprocessen. Finland använder torvmarker i skogsbruket på ett sofistikerat sätt.

Skötsel av ekholmar och eftersatta ekbestånd på låga boniteter : en fallstudie

This case study is made on assignment of Södra, region Öst, as a part of a campaign promoting more active management of the oak forests in the region. Hardwood trees of good quality, especially oak, has a high value due to that the sawn material is highly estimated by the market. It is important that the Swedish oak forests are managed in a proper way in order to meet the future demand. Södra has therefore decided to increase the focus on oak in the Kalmar region and they would like to find out if continues cover forestry (CCF) under certain conditions can be an appropriate management model. The motive is to make use of the existing oak forests more efficient, not just considering well managed forests but also the more neglected oak forests, on poorer soils. Thus, the objective for this study is to examine if CCF is appropriate method in the three stand types; broadleaved mixtures oak forest, oak islet, and oak/spruce forest. Existing management models were surveyed in the literature.

Vindfällning, tillväxt och plantuppslag i en 13-årig granskärm i Medelpad :

The interest for alternative forest Regeneration methods increased significantly during the 1990´s after 50 years dominance of the clear-cutting system (Holgén & Hånell 2000). One reason for this was that clear-cutting was being more and more questioned by different envi-ronmental organizations and because the forest sector for economical reasons wanted to find cheaper ways to regenerate forests. In the beginning of the 1990´s two shelterwood experi-ments were established in a joint effort by Svenska Cellulosa Aktiebolaget (SCA) and the Dept of Silviculture, Swedish University of Agricultural Sciences (SLU). The experiments include various forms of cutting and shelterwood densities and represent productive spruce forests in central and north Sweden (Roggsjön in the province of Medelpad and Skikkis-jöberg in the province of Västerbotten, respectively ). The experiment next to Roggsjön has been reported earlier in three MSc theses, and is also the focus of this thesis.

Generell hänsyn vid avverkning : påverkan av dispens från sexveckorsregeln samt skogsägares kunskap, tankar och åsikter

The forests in Sweden have, for a long time, been managed intensively. This has led to even-aged stands with few tree species and a lack of dead wood. Therefore, general conservation measures in connection with Regeneration felling are important in order to promote biodiversity. Inventories carried out by the Swedish Forest Agency, however, show that about 25 % of the felled area does not reach the level of the Forestry Act, regarding general conservation measures. The aim of my study was to see whether exemptions from the six week notice of reporting Regeneration fellings (the Forest Agency demands a report six weeks in advance of fellings), affect the results of the general conservation measures taken.

Lövsuccessioner i sluttningar längs nedre Umeälven :

Secondary deciduous forests, which have their origin in earlier pasture- and meadow-land in slopes along the lower reaches of the Ume river, are thought to contain high nature conservation values, in spite of a relatively low age. The aim of this study was to clarify how factors as historical use, exposition, disturbance dynamics and successional age influences the conservation values in these types of riparian forests and how this can be implicated in the practical work with conservation and management at Umeå municipality. Sample plots were placed in seven stands with a variation of their historical use, exposition, disturbance dynamics and age of succession. Conservation values as structure, tree-Regeneration, abundance and composition of vascular plants, amount of dead wood and the abundance of signal-species were measured and registered. The species composition and especially the composition of tree species, differed between forests with different exposition and different historical use.

Vad påverkar skogsägarnas naturhänsyn vid föryngringsavverkning i region Mellannorrland? :

The objective of this thesis was to investigate what influence nature conservation measures taken at Regeneration felling. Factors analysed were the forest owners´ situation and their characters, and information activities from wood-suppliers and the Regional Forest Board (RFB). The inventory was performed with a posted questionnaire followed up by telephone to forest owners and a posted questionnaire to wood-buyers. The forest owners were grouped in three strata, depending on the quality results (D- polytax inventory) of the taken forest conservation measures, and for this investigation forest owners were sampled from the population in the tree groups. In total 73 % (41/56) of the sampled forest owners answered the questionnaire Group A (17 answers): Good judgement Group B (19 answers): Bad judgement Group C (5 answers): This group was formed from the forest owners that were informed, by RFB, about nature conservation measures and culture history consideration before the Regeneration cutting.

Betydelsen av taggbuskar, ljus och hävd vid föryngring av ek (Quercus robur)

Many species and hence biodiversity depend on old, large oaks (Quercus robur) with hollow trunks. The populations of oak-living organisms have to migrate to a nearby old oak in order to survive the death of the host. The oak district south of Linköping, Sweden, is unique in area and the number of old oaks. It is anyway doubtful whether Regeneration of oak will secure future continuity. Oaks are light-demanding and thrive in open pastures.

Hyggesbränning på Orsa besparingsskog - en studie på tillväxt och föryngring,15år efter etablering

The main purpose with this study was to investigate whether the tree growth differs or not in prescribed burnt areas compared to mechanically scarified. Together with the result from the main purpose, answers of whether it's possible or not to combine nature conservation with tree production in prescribed burnt areas was presented. In these areas the Regeneration were analyzed to see if there was enough tree plants to comply with the Swedish Forestry Act regulations terms for approved Regeneration. A field survey was conducted at 6 objects, three objects for prescribed burning and three for mechanically scarification. All objects were planted within the same year.

Mognad och läkning av hästens ytliga böjsena

Hästens ytliga böjsena är en mycket viktig men samtidigt utsatt struktur som får ta emot stor belastning. Den hjälper till att göra hästen till den atlet den är genom att lagra och frige energi för effektiv rörelse. Skador på den ytliga böjsenan hos häst medför stora problem i och med långsam läkning, brist på effektiva behandlingar samt försämrad funktion i vävnaden efter skada. Sammantaget leder det till lång konvalescens och stor risk för att skadan återkommer. På grund av detta har man länge poängterat betydelsen av att förebygga istället för att behandla dessa skador.

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