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813 Uppsatser om Didactical indicator species - Sida 4 av 55

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.

Skogsentreprenadföretagens lönsamhet :

During some time there has been a debate whether or not logging contractors? profitability can be considered poor. The contractors? situation is important for maintaining long term relationships and continuity in the forest industry. A thorough analytic picture is however missing.

Lämpliga främmande trädslag för Kalmar och Mönsterås kommuner

This report concerns the for Sweden foreign tree species hybrid larch, hybrid aspen and poplar, and focuses on the area Kalmar and Mönsterås municipalities. The report shows that there are not only advantages with these species. The larch, the most common of the alien tree species has the greatest problems due to that its timber is difficult to sell in the area but also the Larch´s poor pulp quality and is more likely to be damaged by wildlife than the spruce is. Hybrid Aspen is much easier to sell and is used like regular aspen for match wood and textile pulp. Its disadvantage is the high cost for plants and to prevent damage from wildlife.

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.

Rhododendron ur undersläktet Vireya - något om dess karakteristika och användning i nordiska vinterträdgårdar :

Present essay aims to introduce the reader to central topics regarding Rhododendrons of subgenus Vireya. As a result of a donation, the Swedish University of Agricultural Sciences, received a collection of Vireya from a local amateur grower, Kurt Myllenberg. Since the subgenus Vireya is uncommon in Scandinavian horticulture, the study tries to establish conditions for successful growing. The subgenus Vireya differ from the other Rhododendron species through mainly three characteristics: the presence of two tails, attached to each end of the seed; the ovary-style junction is tapering and the pedicels arises directly from a dome-like base and form an umbel and not a raceme. The subgenus is distributed mostly in the islands of Indonesia and New Guinea, but also from Malaysia to Nepal and in Australia. Since Vireya species mainly grows as epiphytes in the tree canopies, they need high drainage and not too much water.

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.

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.

NATURMINNENS F?RVALTNING OCH SKYDD: Inventering i V?stra G?taland

Natural monuments are natural objects with special protection due to their high natural value or cultural significance. The natural value is determined by the occurrence of signal species found on and near the natural monument. The law surrounding natural monuments has evolved a lot since the first ones were declared, and today the title natural monument can be replaced with the title tree with high conservation value. The title has come later and can sometimes overlap natural monument. Some natural monuments lack the qualities required to be classified as a natural monument or a tree with high conservation value, but have a cultural importance.

Identifiering av lek- och övervintringsområden för lax (Salmo salar) och öring (Salmo trutta) i Klarälven

Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).

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.

Effekterna av urbanisering, barksprickedjup och solexponering på lavfloran i sydöstra Sverige

Studies have shown that air pollution, as well as bark fissure depth and sun exposure of a tree can have an effect on lichen growth as well as abundance of lichen species. The aim of this study was to find out the relative importance of these factors. 211 oaks in south eastern Sweden were surveyed for presence of 17 lichen species, as well as the total number of lichen species. Half of the trees were situated in urban areas and half in the countryside. For each tree the bark fissure depth was measured and the sun exposure of the trunk was estimated.

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.

Grey-sided vole and bank vole abundance in old-growth forest patches of different size and connectivity

Vole populations in northern Scandinavia vary in cycles with peaks every third or fourth year as described by the National Environmental Monitoring Programme of small mammals (NEMP). Some vole species have declined in population numbers since the NEMP started in 1971, especially the grey-sided vole (Myodes rufocanus) which is nearly extinct in the forested region. Since small mammals are an important food source for several avian and mammalian predators, the decline in vole numbers is expected to have consequences for the whole food chain, especially if other vole species start to decline in numbers. This study tried to test the hypothesis that presence and abundance of M. rufocanus (a specialist species) and Myodes glareolus (a generalist species) can be predicted by patch size and connectivity of forest patches >60 years old with a minimum of 15% pine >100years old.

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