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1427 Uppsatser om Population density - Sida 1 av 96

Rådjur (Capreolus Capreolus) på Gotland : populationsutveckling och spridningsmönster

Gotland is an island in the Baltic Sea where man has introduced roe deer. The last successful reintroduction was in the 1980s and is the base of the viable roe deer population of today.The aim of this study was to estimate the roe deer Population density in 2012 and the species population dynamic since the time when studies on the population started. The result indicates a population size of 850 roe deer in 2012. There was no significant population dynamic, which may be due to insufficient data. The population occurs basically over the whole island but have not yet been established in all suitable areas.

Influence of the habitat on the potential for cannibalism and population dynamics in stream-dwelling European grayling (Thymallus thymallus L.)

Cannibalism can have major influence on fish population dynamics. A prerequisite for cannibalism is that the cannibal and the potential victim meet, and besides density effects, the encounter rate between cannibals and their victims is therefore also largely dependent on habitat use and habitat heterogeneity. In this study I quantified and compared the potential for cannibalism in stream-dwelling European grayling populations in three rivers in Jämtland by means of habitat classifications. I also analyzed population dynamic consequences of varying the potential for cannibalism in terms of intensity, using a physiological structured population model. Findings based on habitat characteristics were that the potential for cannibalism is in general not favourable in these types of streams.

Fåglar i urbana miljöer : kvaliteten på urbana habitat och om beståndstäthet är ett bra mått på habitatkvalitet

The urbanization of the world is increasing. How it affects bird populations have been well studied during the last decade, and comparisons between urban and non-urban habitats have been carried out. A common method for measuring habitat quality is to calculate the Population density. This method is easy to use, but have been criticized during the last couple of years. In this study, data of population densities was compared with data on reproduction success.

Balis trädgårdar

The urbanization of the world is increasing. How it affects bird populations have been well studied during the last decade, and comparisons between urban and non-urban habitats have been carried out. A common method for measuring habitat quality is to calculate the Population density. This method is easy to use, but have been criticized during the last couple of years. In this study, data of population densities was compared with data on reproduction success.

Flottledsåterställning i norra Sverige: : effekter på habitatkvalitet och populationstätheter av juvenil öringar (Salmo trutta L.)

In an effort to evaluate the effects of restorations of float ways on Population density of stream dwelling fish in relation to the changes in habitat, I studied the physical habitat restored and channalized sites and their Population density of brown trout (Salmo trutta L.) in three streams in the municipality of Sorsele. The differences between the channalized and the restored sites where most noticeable regarding substrate which where generally coarser in the restored sites. The analyses showed that the proportion of habitat that where suitable to the age class 0+ where significantly lower in the restored sites compared to the channalized sites. Regarding age class ?2+, no statistical differences in habitat quality were found.

Wild boar paradise : What makes the Swedish wild boar reproduce more or less successfully?

Due to the growing wild boar (Sus scrofa L.) population in Sweden there has been an increase in wild boar related traffic accidents, damage on cropland, and conflicts regarding the management of the wild boar. Knowing what makes the wild boar reproduce and survive more or less successfully in different geographic areas is an important part of managing the population. According to previous studies the wild boars rate of increase varies from county to county. The aim of this study was to test, on the county scale level, if landscape composition and diversity as well as people and hunter densities might be the reason for this variation. The first hypothesis was that a big proportion of forests and cropland would increase the rate of increase.

Kartläggning av Sveriges landstings användning av telemedicin

Sweden's aging population makes the need for a viable health care urgent and telemedicine can be a solution to enable older people to receive or give themselves care in their homes. Furthermore, implementation of telemedicine has the potential to realise profits in society by increasing the accessibility of health care and minimizing travel costs. Sweden?s low Population density and geographical configuration makes the advantages of telemedicine even more appealing. To illustrate the differences between the county councils? use of telemedicine and thus increasing the possibility for coordinated care between them, the authors have on behalf of the Innovation Centre at the Karolinska University hospital mapped the amount of telemedicine technologies that are available in the Swedish county councils? today. To collect information an electronic survey and video or telephone interviews were used.

Genomisk selektion inom köttraser

Genomic selection (GS) is used for selection of breeding animals of dairy cattle. GS is though not as extensively used within the beef industry. One reason for that is the low accuracy (rTI) of the breeding value that is of great importance for the final genetic gain. Causes to the low accuracy are high effective population size, a small reference population and a genetically differentiated population. There is however a market for genomic selection with High Density (HD) tests for beef cattle.

Påverkas mosippa (Pulsatilla vernalis) negativt av igenväxning?

Pulsatilla vernalis is one of several endangered plant species that benefit from wildfires and small scale disturbance events that repel competing vegetation and create open patches in the vegetation cover. Previous studies argue that Pulsatilla vernalis is decreasing in numbers due to vegetation changes associated with the decrease in wildfires, forest grazing and changes in forest management. In this study, 17 populations of P. vernalis were inventoried in order to examine if soil and/or vegetation structures affect the population structure of P. vernalis (i.e.

Stadsrum och stadsliv - Bebyggelsestrukturers inverkan på kvalitet och innehåll i det offentliga

ABSTRACTToday's modern technological society is constantly evolving and house planning is one area that is constantly creating new technical solutions. By looking back at selected architectural eras during the 1900?s, the idea is to study and analyse three building structures in Gothenburg with a focus on quality and content in the urban space.In order to provide a background for the three selected areas, their history has been studied. The main question for the research is: how do different building structures affect the content and qualities in the urban space?The areas have been selected to represent three typical epochs in Swedish building history.

The efficiency of the newly launched predatory mite Amblydromalus limonicus : biological control of thrips in cucumber

In this study, the efficiency of a newly launched predatory mite, Amblydromalus limonicus, has been examined for its potential to use as a biological control agent in cucumber production. A. limonicus can be used for biological control of two thrips species, Frankliniella occidentalis and Thrips tabaci. Field trials were conducted in greenhouses of two conventional cucumber growers in Scania, the southern part of Sweden. The basic control agent used against thrips was the predatory mite Amblyseius swirskii. In selected areas, additional A.

Konkurrens mellan rådjur och dovhjort

The main purpose of this report is a first step to cover the scarcely investigated subject of interspecific competition between roe deer, Capreolus capreolus, and fallow deer, Dama dama. The report focuses on the distance between individuals of roe and fallow in the study area as well as which factors that is affecting the variation in distance depending on fallow deer group size and changing Population density over time and in two areas. For additional information the history of the populations, such as harvest and distribution, is also investigated. The report came to the conclusion that interspecific competition between the species do occur. The elevated distance between individuals of the two species is clearly significant. The most important factor affecting the distance seemed to be the size of the fallow groups.

Inverkan av nederbörd, temperatur och frost på årsringens egenskaper hos boreal tall (Pinus sylvestris L.) :

The wide distribution range of our boreal pine (Pinus sylvestris L.) provides a great variation in growing conditions and climate/weather factors that influence the wood development of the trees. A great number of extensive studies have been conducted over the years in order to clarify growth trends of this and other species over more or less wide-ranging areas. In this thesis effects of weather factors were instead compared between different forest stands from the about same geographical location. The effects of precipitation, temperature and frost on the year ring characteristics of pine were studied in the research forest of Svartberget Vindeln, in northern Sweden. The stands differed in site index and silvicultural treatment; fertile ? high stem density, fertile ? low stem density, poor ? high stem density and poor ? low stem density.

Det sjuka benet och de friska människorna : en studie av osteoporos och osteoartrit i kvarteret Banken 1 i Visby

This essay deals with the diseases osteoporosis and osteoarthritis in a medieval population from Visby in Sweden. The aim has been to evaluate to what extent and in what way these diseases have influenced the people of a relatively large harbour town during the Middle Ages. 24 individuals were analysed osteologicaly and 19 of them became subject for measurements of bone density through DEXA readings. Furthermore four individuals were x-rayed based on external differences due to osteoarthritis and a change in the depression at the base of the medial surface of the greater trochanter. Similar studies have been made in Trondheim, Norway and Wharram Percy, Great Britain.

Social hållbarhet och förtätning : en kritisk studie i förtätningens sociala paradoxer

Densification is one of the urban visions for sustainable development - a vision that has become a part of the solution to the unsustainable sake dilemma. With the dense city land will be saved, energy consumption reduced and social cohesion improved. The dense city is considered to be ecologically, economically and socially sustainable. Applying an urban design concept has thus proven to be problematic. Density has been found to be a complex concept which is far more complicated than measuring how much built surface that needs to be covered. It is also not disputed what different degrees of densification mean and whether densification in itself is sustainable.

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