Sök:

Sökresultat:

745 Uppsatser om Threatened species - Sida 2 av 50

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.

H?RNERVMOSSANS P?VERKAN P? LJUNGHEDENS ARTM?NGFALD: En f?ltstudie fr?n Sandsj?backas naturreservat

Campylopus introflexus is a moss species that originates from the southern hemisphere and has spread worldwide during the 20th century. Today it is classified as an invasive alien species in many countries, and it has been seen during inventories that it has become widespread in Sweden as well. The purpose of this essay is to contribute to new knowledge about how this moss affects species diversity on Calluna heathlands in Sweden. The study includes both fieldwork and an analysis of scientific literature on the subject, and the question that is answered is if C. introflexus has an impact on species richness in the heather peat.

KLIMATTOLERANS HOS URBANA TR?D I G?TEBORG: Analys av klimatgr?nser och framtida klimathot

Urban trees contribute significantly to our society. By providing ecosystem services and a habitat that other urban species and ecosystems depend on, both biodiversity and the people in the city benefit. Some characteristics that the trees possess include functioning as biological filters for the atmosphere and water, as well as positively impacting people's mental health. However, urban trees are challenged by stressors such as pollution and a drier environment, making them particularly sensitive to climate change. The goal of this study was to estimate the expected magnitude of climate change in Gothenburg and compare it with the current urban species' natural climate boundaries to understand the extent of the climate threat and which species appear to be most at risk.

Habitat preferences and reproductive success forthe threatened longhorn beetle Plagionotusdetritus

Plagionotus detritus is a threatend longhorn beetle that only exists at one site in Sweden. It is saproxylic and depending on recently dead coarse oak wood for its larval development. Trees at Djurgården, Stockholm that have been colonized by Plagionotus detritus has been studied to find out the habitat preferences of the species and to see what affects the density of beetles in a tree. The bark of some trees and wood from the breeding project at Nordens Ark has also been studied to find out what affects the species reproductive success. The reproductive success was measured in two ways, the larval mortality and the size of the hatching holes.

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.

Betydelsen av anlagda våtmarkers area och ålder för förekomst av sjöfågel inom Linköpings kommun

The aim of this study was to examine what impact restored and constructed pounds and wetlands have on waterfowls in the area of Linköping. The birdlife in five constructed wetlands werechosen to investigate if specific factors like age, size and vegetation affected the avian diversity in wetlands. Also, extra focus has been given to the threatened Horned Grebe (Podiceps Auritus), breeding in the studied area. The results showed that the number of species as well as individuals of waterfowl and Horned Grebe changed over time in what might be a result of succession in the wetlands. Comparing the number of birds to the size of the wetlands showed a clear correlation. Larger areas inhabited greater numbers of species and individuals.

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.

Environmental variables determining the occurrence of Cladonia parasitica and Hertelidea botryosa, two boreal lichens confined to wood

Biodiversity is essential for human well-being and it is defined as the genetic variation within species and the variety of species and ecosystems. Biodiversity provides several ecosystem services which are necessary for human beings but there are different threats towards the biodiversity. The biodiversity linked to the forest in Sweden are threatened, about 50 % of the red-listed species in Sweden are associated with forests. This is linked to the commercial exploitation of the boreal forest in Sweden which started 200 years ago. The forestry the last 50 years, with clear-cuts, have contributed to a fragmented forest landscape.

Sand pits as habitat for ground beetles (Carabidae) : does the area affect species number and composition?

Sand pits are a valuable habitat which can hold many sand living species including several endangered ones. As many sand habitats with exposed sand are declining, sand pits have a potential as a substitute habitat. This study was conducted to see what effect the area of a sand pit has on species number and composition of ground beetles (Coleoptera: Carabidae). Also, the effects of other environmental variables were tested, for example the proportion open sand, vegetation cover, sun exposure and tree cover. The study was conducted in the county of Uppsala in 2008 and included 13 sand pits with areas between 200 and 180,000 m2.

Biodiversitet av evertebrater på vegetativa tak

In a city sometimes conflicts arise between either to save the species-rich vacant lots where many species thrive, or to build new buildings. Green roofs can then serve as a refuge for plants and animals that have had their natural habitat destroyed or diminished. Today we know too little about green roofs contribution to the biodiversity in the cities. We also know very little about how various types of vegetation on roof can increase biodiversity and its ability to attract different species.The aim with this study was to examine how different types of vegetation on the roofs affect the biodiversity of the invertebrate and how species-composition and number of individuals differ between the roof- and groundlevel.This study has been carried out on Augustenborg Botanical Roof Gardens in Malmo, and in an area about 1.5 kilometers away from Augustenborg. Three different types of vegetation on the roof and ground floor were selected: sedum- ruderal and grass.

<- Föregående sida 2 Nästa sida ->