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912 Uppsatser om Tree species - Sida 10 av 61

Svartgran ? ett alternativ när allt ser mörkt ut? : en kartmodell för att visa lämpliga ståndorter för odling av svartgran

A common problem in forestry is plant death caused by frost. The risk of frost is highest on wind protected, flat or low-lying areas in the terrain. Here you often have regeneration problems with Norwegian spruce which is especially sensitive to spring frost. Swedish tree experiments have shown that the black spruce can be a suitable alternative on these areas, for example on moisture frost prone areas. The species originates from North America and its pioneer tree characteristics make it more frost hardy than Norwegian spruce.

Qualities and supply of suitable dead wood for Ceruchus chrysomelinus and its dispersal pattern in a translocated population

The wood-living beetle Ceruchus chrysomelinus is a rare species connected to natural forests. In Sweden, it is red-listed as endangered (EN) and an action plan for its preservation has been done by the Swedish Environmental Protection Agency. In this work I have therefore investigated how a translocation of the species succeeded after 17 years. I aimed to study the species dispersal biology, its substrate preferences and the supply of suitable wood on this site. The study was performed during 2012 in Pansaruddens nature reserve close to Uppsala in Sweden, which is a spruce dominated forest.

The effect of cold stratification on germination in 28 cultural relict plant species : with the purpose of establishing germination protocols

Cultural relict plant species from the Nordic countries have been collected by the Nordic Genetic Resource Center (NordGen) for the purpose of conservation. To ensure high seed vitality in store, regular germination tests need to be conducted. It is important to get a correct viability status, but the knowledge of seed dormancy in the cultural relict plants is often poor. The objective of this study was to investigate how seed dormancy is affected by cold stratification. The study includes 31 accessions from 28 species with the purpose of establishing germination protocols.

Poppel - en möjlighet i norra Sverige?

The countries in the European Union have agreed to increase their percentage renewable energy sources to 20 %. To reach this goal an increase of biomass production needs to be made. One way of achieving this is by using nonnative species. Poplar in Sweden produces biomass faster than the domestic trees. In the southern parts of Sweden plantations has been made with good results. In the northern parts survival is a problem that needs to be solved before plantations can be made for commercial use.

Härdiga palmer för skandinaviskt klimat :

The final thesis ?Hardy palms for scandinavian climate? describes the family Arecaceae both from a general point of view, and with individual descriptions of seven different species that are known for their coldtolerance. The descriptions of each species is brief and the intention has been to give an introduction to some specific species known for their hardiness. Seperate chapters discuss topics as hardiness, pests and other problems and a short instruction for growing palms on open land in scandinavian climate. Finally a short discussion about continued research on this topic and some conclusions ends this final thesis.

Förändringar i vegetationens sammansättning efter en våtmarksrestaurering : Changes in the vegetation composition after a wetlandrestoration

The loss of such great wetlands, which has arose in Sweden the last decades, has created a situation that threats both the function and the biological diversity within the wetlands. Many ecological niches can be found in the wetlands and it is one of the habitats where most different species exist. In the 17th Century people started to ditch damp environments, such as bogs, to create a productive cultivated ground. Further ditches were made when the forestry gave large economical profits. The wetlands were impoverished from both groundwater and nourishment, and this led to a great loss of species.In a corporation with WWF and Skogsstyrelsen in Arvika, the University of Karlstad has participated in the Laskerudproject, a hydrological restoration-project in a forest landscape.

Kostnader vid gallring med flerträdshanterande aggregat, från skog till industri

Profit in first commercial thinnings of today is hard to achieve. This is because of prevailing pulpwood prices and because of high costs of logging and transport. To reduce these costs higher productivity is advocated. One way to increase the productivity is the use of multi-tree handling harvester heads. The aim of this study was to calculate logging and transport costs in first thinnings, where multi-tree handling has been used.

Är vi lika dem? : en kraniestudie av hominider ur ett evolutionistiskt perspektiv

By examine plastic craniums from eight different hominids I wanted to find morfological characteristics that agreed with those of modern humans. The species that were selected had a plastic casting of its cranium in the laboratory at Gotland University. My focus was on species from the family Australopithecius and Homo and only working with their craniums. And this because the cranium and the theeth shows the most visible morfological characteristics between the different hominids. I also wanted,in a small part of the essay, to write about the differences in now living primates and humans skulls.Except from analysing the plastic castings I also studied surveys written by other scientist on the same subject.

Detection of Honey Bee Viruses in Apis mellifera and Apis cerana

Two species of bees in the genus Apis, real honey bees, has long been of interest for man. These two are the European honey bee, Apis mellifera, and the Asian honey bee, Apis cerana. In Vietnam, beekeeping is of great importance, both with A.cerana and A.mellifera. The aim of this project was to investigate if the introduction of the European honey bee in Asia has affected the Asian honey bee, and whether different pathogens from A.mellifera have been transferred to A.cerana. Totally 40 samples, 20 from every species, were analysed for 8 different viruses.

Studier av habitatval och revirstrukturer hos vassångare (Locustella luscinioides) i Tåkern

The Savi?s Warbler (Locustella luscinioides) is a recently established bird species in a few reedy shallow lakes of southern Sweden and has only been found nesting for the last twenty years. Little is known about the species' habitat preferences, breeding biology and demands for specific territory structures at breeding sites in Sweden. Knowledge of a newly established species? habitat requirements is essential to maintain a viable population and design action plans.

Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt :

Reindeer husbandry and Forestry are both area related industries and will in big extent use the same lands. Conflicts often arise because of that the industries have different interests. Many of the activities done by the forestry influences the reindeer husbandry in an undesirable way, simultaneously as the reindeer husbandry activities can have negative consequences for the forestry. One such forestry activity is fertilization. It was during the 1960´s forest fertilization began to be practiced and the reason was that the increase in growth that the fertilization gave could be able to cover for the future shortage in wood many feared. During the 1970´s when the fertilizing activities were most intensive about 200 000 ha was fertilized annually.

Utilization of different habitatsin Colobus angolensis palliatus in the forests of Diani Beach, Kenya

The Angolan black and white colobus monkey (Colobus angolensis palliatus) is an arboreal primate that inhabits coastal forest fragments on the south cost of Kenya and is consequently vulnerable to forest fragmentations. The study was carried out in March and April 2011 in Diani Beach in Kenya where two of the largest populations of the species are distributed. This study is a pilot study to test methods for a Master?s thesis. The aim was to investigate any variations in use of two habitats of C.a.

Optimering av testning av säkerhetskritiska funktioner

Inom industrin används olika testmetoder för att uppnå hög kvalitet i mjukvarukontrollerade system. Kvalitetskraven är särskilt höga för säkerhetskritiska system t.ex. styr- och reglersystem i fordon. I det här examensarbetet används två analysmetoder (Fault Mode and Effects Analysis och Fault Tree Analysis) för att ta fram ett nytt säkerhetstest för ett broms- och växlingssystem som Scania tillverkar. Det studeras även hur formella metoder kan användas för att ytterligare öka kvalitet ochh tillförlitlighet.

Amfibier i nyanlagda våtmarker : En fältstudie i Laholms jordbrukslandskap

Many species of amphibians are threatened both in Sweden and globally. The causes are many and a main factor is habitat alterations which often results in populations being isolated. Changes in the agricultural landscape have among other things resulted in small water bodies being filled and dried out and that has severely affected the Swedish amphibians. Swedish amphibians are depended upon small water bodies for their reproduction. Wetlands have been constructed to reduce the impacts of the eutrophication in the Laholm bay.

Tesaurer eller ontologier? Eller både och? : En jämförelse mellan två typer av ämnesordssystem med tanke på deras förbättring av effektiv informationsåtervinning

By examine plastic craniums from eight different hominids I wanted to find morfological characteristics that agreed with those of modern humans. The species that were selected had a plastic casting of its cranium in the laboratory at Gotland University. My focus was on species from the family Australopithecius and Homo and only working with their craniums. And this because the cranium and the theeth shows the most visible morfological characteristics between the different hominids. I also wanted,in a small part of the essay, to write about the differences in now living primates and humans skulls.Except from analysing the plastic castings I also studied surveys written by other scientist on the same subject.

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