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195 Uppsatser om Boreal lake - Sida 7 av 13

En tidsseriestudie av varviga sjösediment fra?n Kassjön

This thesis aims to analyse a time series containing the annual accumulation rate of minerogenic matter in the lake Kassjo?n. First there is a theoretical survey of some frequently used tools for the analysis of time series in the time domain and in the frequency domain. This survey is followed by a simulation study that illustrates how the theoretical tools work in practice. After this, the time series "toolbox" is used to analyse the time series from Kassjo?n (5701 data points).

Evighetsträd

FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation. This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock.

Stridsyxor eller båtyxor : En diskussion om symboliken och dess betydelse

My intention with this paper is to try to understand the meaning of the double sex symbols which can be identified on a number of Neolithic so called battle axes from the region round the lake Mälaren in Sweden. My conclusions are drawn after having studied a number of archaeological thesises. I have realized that the society was egalitarian from what is said about the funeral habits since women and men were buried with the same care. Ceramics from the Skogsmossen site show a very long continuity over 15-20 generations. These facts indicate a peaceful society without traumatic breaks where knowledge would have been lost.

Separation av två klasser av åtta-dimensionella reella divisionsalgebror

This thesis aims to analyse a time series containing the annual accumulation rate of minerogenic matter in the lake Kassjo?n. First there is a theoretical survey of some frequently used tools for the analysis of time series in the time domain and in the frequency domain. This survey is followed by a simulation study that illustrates how the theoretical tools work in practice. After this, the time series "toolbox" is used to analyse the time series from Kassjo?n (5701 data points).

Underkambriska böljeslagsmärkens bildningsmiljö : Ett försök att fastställa fossila ripplars avsättningsmiljö med hjälp av recenta sandbottnar

ABSTRACTThe fauna of the Lower Cambrian is far from fully understood, as is the environment of that epoch. Some of the most crucial moments in the history of evolution takes place during this epoch; the Cambrian explosion and the appearance of ecosystems as we know them. That makes it an important period to investigate. Doing so, the Lower Cambrian offers a lot of problems, one of which is that body fossils are seldom preserved. That has often left us with trace fossils to create an image of the Lower Cambrian life, but also some bedrock features such as ripple marks.The main purpose of this work has been to investigate the possibilities of relating the wave lengths and forms of recent wave-generated ripples to fossil ones, and also to evaluate the methods for that kind of comparison.

Status och hotbild för den oceaniska laven broktagel Bryoria bicolor i sydvästsverige :

Horse-hair lichen Bryoria bicolor is a red-listed lichen species in the category Vulnerable. It is an oceanic lichen and it is often found on boulders and cliffs in a semi-open environment with a high humidity in the agricultural landscape. The species can also be found as an epiphyte on trees, mostly in boreal forests in the provinces of Dalarna, Härjedalen and Jämtland. In the agricultural landscape, there has been indications on that B. bicolor show a decline, and this studie aimed at examining the extent and causes of this decline.

Skaftslamkrypa (Elatine hexandra) i Bolmen, utbredning, tillväxt, reproduktion och styrande faktorer

The plants in the genus Elatine are characteristic for oligo and mesotrophic lakes. This study focuses on Elatine hexandra one of the four species in Sweden. It is stated as vulnerable by the National Environment Agency and a conservation plan with guidelines to preserve the plant in Sweden is under preparation. There have been a few previous studies investigating this plant in other countries but this is the first one for Sweden. The aim of this study was to investigate the distribution, growth and reproduction of E.

Whispers in the forest : a field study about communication within Vi-agroforestry

The purpose of this study is to explore and understand the social and structural dynamics of an organization working with questions regarding development. The organization in question is Vi-agroforestry, a Swedish based NGO that works around the lake Victoria basin and the focus will be on their office in Rwanda. I have used a qualitative approach and conducted participatory observation as well as semi-structured interviews to gather data. I have emanated from the individuals in the organization by using a theory of microsociological organisationperspecive to understand how the employees create and is created by the existing social structures. (Blomberg, 2003) Even though the office in Rwanda only is a relatively small part of Vi-agroforestry?s operations it is still highly individual and independent from the rest of the organization.

Storyline: en resa ovanför norra polcirkeln

Med vår undersökning ville vi ta reda på om storyline som arbetsmetod befrämjar elevernas lärande om livet den norra Polcirkeln. Utvecklingsarbetet genomfördes i tre olika klasser i årskurs fyra och fem i Crystal Lake, Illinois, USA. Ur dessa klasser valde vi att titta närmare på tre elevgrupper. Förberedelserna bestod i att samla material i Sverige, t.ex. fågelvingar, pälsbitar från djur och dylikt, då vi anade att de amerikanska eleverna inte hade några större förkunskaper, vilket är en av grundtankarna med storyline.

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.

Lilaköttig taggsvamp, Sárcodon fuligíneovioláceus : miljökrav i Sverige och en analys av vad som styr artens etablering

Burnt Spine-cap Sárcodon fuligíneovioláceus are one the most endangered mycorrhizal fungal species in Europe. They have their main distribution in Sweden. It form mycorrhiza with pine and dependent on limestone, which makes it connected to a rare environment. It has therefore been important to study the ecology of it further and to recognise the requirement it has on the environment more accurate and what it need to establish in a new area. In this study, 31 of 34 known sites in Sweden was visited and studied in field and their history analysed through aerial photographs.

Spawning site selection of brown trout in habitat restored streams

During the timber floating era, most of Sweden?s watercourses were altered. This decreased the amount of available spawning habitats for salmonids, and hence had a negative effect on the riverine brown trout (Salmo trutta) populations. Reconstruction of spawning grounds is today a common measure in restoration of altered streams in Sweden. However, very little evaluation of the effectiveness of these reconstructed spawning grounds exists.

Clear-cut and substrate characteristics important for the occurrence of the beetle Upis ceramboides

Disturbances, such as fire and wind, are important for saproxylic beetles (= beetles depending on decaying wood) to gain substrate in boreal forests. Clear-cutting is an example of a man-made disturbance. Measures such as prescribed burning have been made to resemble natural disturbances. The aim of this study was to see which clear-cut characteristics are important for the occurrence of the saproxylic beetle Upis ceramboides. This is a species favored by open habitats and is said to respond positively to forest fires. The distribution area in Sweden for this species has decreased during the last two centuries and I wanted to see if there were differences between clear-cuts in Hälsingland, where it is very rare and decreasing, and Norrbotten where this study was conducted.

Naturupplevelse och psykisk hälsa : Hur påverkar naturupplevelser människor med stress- och utmattningssymtom

Stress-related diseases in Sweden have doubled since 1997. Even longterm sickness related tostress has increased over the last decade. In future there is a need of alternative methods todecrease the amount of people being affected to gain a better population health. Natureassisted therapy (NAT) was shown to be a successful method as part of the therapy of stressand burnout likewise was nature an important factor to prevent people from mentaldisorders. The aim of this study was to analyse the latest research concearning nature and itshealth effects with focus on stress and burnout patients in order to plan health promotingactivities outdoors for these patients.

Bottenfaunan i Stensjöån och dess tillflöde Bokån : - en undersökning av tre lokaler

The purpose of this study has been to examine whether the bottom fauna of the stream Stensjöån, has been negatively influenced since the harvesting of peat began on the nearby peat moss Skäftesmyr or not. Comparison has been made with the results of index calculations from earlier examinations in the stream, two calculated indexes has been made, Danish fauna index and ASPT-index. The sampling was made with the kick sampling method, SS-EN 27 828. Three locations were chosen for the examination, one upstream from the peat moss, one just downstream from where the brook from the peat moss joins Stensjöån and a third location near the outlet of the stream to the lake Stensjön. The samples were sorted and the found animals identified to the taxonomic level required for the calculation of the two indexes.

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