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799 Uppsatser om Species differentiation - Sida 1 av 54

Individuell tillväxt och substratval hos en lokalt differentierad population av Asellus aquaticus

Local differentiation may occur during a short period of time and is part of the formation of new species. The isopod Asellus aquaticus is an example of a species in which local adaptation has occurred during a short period of time. An establishment of stonewort (Chara spp.) vegetation in Lake Tåkern (in the 2000) resulted in two different Asellus ecotypes; a lighter pigmented, smaller one that lives among stoneworts grazing periphytic algae, and a darker, larger ecotype that feeds on decaying leaves in reed (Phragmites australis vegetation. The purpose of this study was to examine whether there are differences in growth between ecotypes, depending on whether the food was periphytic algae or leaves, and to study the choice of substrates between the two food types. For the study, animals from both habitats were brought in from Lake Tåkern to the laboratory.

Bräkanden från förr : att skilja får från getter utifrån kv. Apoteket 4-5 i Visby

To differentiate between bones from sheep (Ovis aries) and bones from of goats (Capra hircus) is a long lasting challenge for zoologists, archaeozoologists and osteologists. Especially considering archaeological remains which are often found fractured and poorly preserved due to taphonomic processes. Zeder & Pilaar?s (2010) and Zeder & Lapham?s (2010) methods of Species differentiation has shown promising results when used on bones from modern sheeps and goats. This paper aims to evaluate these methods by exerting them on excavated bones from kv.

Från monopol till konkurrens : förslag på differentieringskoncept för nya aktörer på den omreglerade apoteksmarknaden

The purpose was to create differentiation concepts due to the upcoming deregulation of the Swedish pharmacy monopoly. Apart from the theory, the study is based on interviews with pharmacy customers and experiences from former pharmacy market deregulations in some of the other Scandinavian countries. The result shows that a differentiation concept that could work in a shorter perspective is a low service quality but with lower prices and a unique location. In a longer perspective it seems like the concept should change to a more service orientated differentiation concept with a variation of high quality services to gain competitive advantage..

Effekter av landskapets sammansättning på humlearters förekomst

The species in the genus bumblebees (Bombus) are important pollinators. In the world there are 250 bumblebee species and there are 34 species in Norway. The purpose of this study is 1) to assess changes in the species composition of bumblebees in twenty different places in Norway that have been inventoried first one time between 1939-1960 and the second time in 2012, and 2) to relate species richness and distributions to current landscape composition with the aid of orthophotos. In this study, I have used regression analyzes on the different bumblebee species that were present or absent at the inventory, using the premises of the following variables: low or high altitude, latitude, longitude and seven different types of land use (farmland, building/plots, open land/pasture, forest, wetland and open or snow-covered ground above the tree line) to see if there was any relationship between each species and the different variables. I have not analyzed what the landscape looked like at the first inventories and therefore we cannot say whether it has changed and if that is why species number has decreased. This would be interesting to study further and to see if there is any relationship between landscape changes and bumblebee?s species decline.

Får är får och get är get : utvärdering av osteologisk metod med stöd av arkeogenetik

The difficullty to distinguish between sheep and goats is a well-known problem in archaeology and osteology. Distinguishing sheep and goats in archaeological animal remains takes time and time is often limited for osteologists. Because of this difficulty osteologists and archaeozoologists often use the term sheep/goat or ?ovicaprids? in their analytical reports. But even if the term sheep/goat comprise both species, this is often not the case when archaeologists and osteologists interpret and present archaeological findings.

Samgång av olika arter på svenska djurparker

Zoos currently aim at keeping animals in as natural habitats as possible, since they havegone from displaying exotic animals to working with conservation of endangered species.It is therefore more common that zoos keep groups composed of two or more species in thesame enclosure. The aim of this report is to study why and how different species are held atzoos. Species in the wild can interact in different degrees depending on season andresources. When species are held together at zoos the space can be more effectively used,the animals increase their activity and the visitors increase their learning. Mixed speciesenclosures involve more work and risks of injury.

Didaktiska arter

The study intends to find easily recognizable indicator species for water quality in the constructed wetland of Flemingsbergsviken. The study is relevant since indicator species can be difficult to determine for common people. Easily recognizable indicator species could improve dialogue between the scientific community, administrative authorities and the general public. Such species could be used in education systems, associations or in information campaigns. Therefore, I have chosen to refer to these species as didactical species.

Fältskiktsarter i naturlika planteringar : vilka råd kan ekologer ge?

This paper appeals to professionals working with green questions. It intends to create a discussion about which plant species that can be established in a fieldlayer of a naturelike planting on fertile agricultural land. To initiate the essay, a studie of which values that can be connected with an establishment of a fieldlayer was performed . A part of Tor Nitzelius Park in Alnarp, a so called naturlike planting on fertile agricultural land, was used as a model for the choice of species. With the aid of soil values, photos and a list of current species, interviews with four ecologists were performed.

Bestämt eller obestämt? En kontrastiv jämförelse av ett antal engelsk- och kinesisktalande inlärare av species i svenska.

Specialarbete, 15 hpSvenska som andraspråk, fördjupningskurs SSA133Vt 2012Handledare: Hans LandqvistExaminator:.

Species diversity and geographical distribution of Fusarium species on winter wheat in two regions in Sweden

Various Fusarium species causes some of the most common cereal diseases worldwide. Besides the yield losses that can be a result of these diseases, strains from several Fusarium species can produce mycotoxins, some very toxic. The aim of this study was to investigate which Fusarium species and how many that occurred in winter wheat grains from Mälardalen and Kalmar län, if there was any difference in the distribution of Fusarium fungi between the regions and the potential within species to produce mycotoxins belonging to the group trichothecenes. Winter wheat grains collected in 2009 from ten fields (unsprayed plots) in the two regions were analysed for Fusarium species. PCR was used to amplify the TEF region where after the samples were sequenced.

Artrikedom av kärlväxter i övergivna och restaurerade hagmarker : betydelsen av igenväxningsgrad och tid sedan igenväxning började

Continuously grazed grasslands have remarkably high plant species diversity. In Sweden this type of habitat has declined for the last two centuries. Changed land use has caused habitat fragmentation and loss of habitat quality. This has caused a great number of plant species to end up on the verge of extinction. To try to save this unique habitat and the species that are tied to it, lots of resources are laid on restoration of abandoned grasslands. In this study, plant species richness of continuously grazed, abandoned and restored grasslands were related to degree of overgrowth, time since overgrowth started and rate of overgrowth.

F?RS?LJNING AV OCH INST?LLNING TILL FR?MMANDE V?XTER I TR?DG?RDSBRANSCHEN

Alien plants that have intentionally been introduced to an area for cultivation in public or private gardens constitute the primary pathway of introduction for invasive alien species that spread into nature. Garden owners want species that have satisfying characteristics, these characteristics are often also linked to plant invasiveness. Thus, the horticulture industry plays an important role by making scientifically based decisions and phasing out invasive plants and replacing them with alternative species with satisfying characteristics, but low risks of becoming invasive. This thesis aimed to examine the sale of and the attitudes towards alien plants in the horticulture industry in Sweden. Alien terrestrial plants identified to have a severe risk, high risk or potentially high risk of spreading and becoming invasive according to ArtDatabankens assessment, were examined to see if they were for sale.

Klimatinducerade fenologiförändringar och dess effekter i näringsväven

The climate affects animal populations through several processes. These processes includereproduction, phenology and the success of hunting. By influencing the phenology of species theclimate also affects the way species interact. If a climate-induced phenology change promotes abasal species to bud earlier in the spring for example, this will affect the links to other species inthe food web due to a time lag in the tropic levels above. This dependence, that a predator has tobeing synchronous to its prey, is called the match/mismatch hypothesis (MMH).

Selecting plant species for the occasion of the 300th anniversary of Carl von Linné at Möckelsnäs :

This report was an outcome of a cooperation between ?The Visitor and Knowledge Project Carl von Linné? and SLU, the Swedish University of Agricultural Science. The aim with the cooperation was to create a garden and to suggest suitable plants for an orangery already built. All species suggested should have a documented relationship with Carl von Linné. The project is located in the southern part of Sweden at an estate named Möckelsnäs not far away from Linné?s birthplace.

Fjällfåglar : En jämförande studie från dal till topp i ett nordligt och sydligt svenskt fjäll

Title: Mountain birds ? a comparative study from valley to mountaintop in a northern and southern Swedish fjeld  Author: Kristian Zackrisson Abstract Main aim in this study was to increase the knowledge about birds in the Swedish mountain area. Three questions were asked: 1) Which bird species can be found during the breeding season along a low mountain slope from a forested valley to a mountaintop with bare mountain environment? 2) Do the number of species and individuals differ in different elevation zones? 3) Is the composition of bird species along a low mountain slope the same in the Kebnekaise mountains inLaplandand the Grövelsjön mountains in Dalarna? Bird census in two study sites located in the Kebnekaise mountains and the Grövelsjön mountains and subsequent analysis of the results from the bird census was the main parts in this study. Totally 20 bird species were found along a low mountain slope in the Kebnekaise mountains.

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