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1033 Uppsatser om Species composition - Sida 10 av 69
Störningsregimer vid Skövde övnings- och skjutfält : Stridsfordons påverkan på olika naturtyper i militära övningsområden
A lot of habitats have declined or disappeared as the old cultural landscape changed to the modern agricultural landscape of today. Places such as power line corridors, racing tracks, gravel pits and military training sites have become refuges for many species associated with the old cultural landscape. These sites have been exposed to ecological disturbances that create the same type of habitats that were found in the old cultural landscape.The military training sites in Sweden has an impressive diversity of species. Disturbances from the military exercises have created habitats that are important for a wide range of species.The purpose of this thesis is to study some of the ecological disturbances occurring in the military training sites of the Swedish Armed Forces and examine how they affect different types of habitats. The thesis explains through litterateur and field studies the reason to the rich biodiversity often found at military training sites.
Predation av sandräka (Crangon crangon) på juvenil piggvar (Psetta maxima) och juvenol skrubbskädda (Platichtys flesus) : betydelse av yngelstorlek för överlevnad hos piggvar och skrubbskädda efter bottenfällning
Turbot (Psetta maxima) and flounder (Platichthys flesus) are two species of flatfish both having their nursery areas around the shores of Gotland in the Baltic Sea. The common brown shrimp (Crangon crangon) is a known predator on newly settled plaice (Pleuronectes platessa) in the North Sea area and is also found in the Baltic Sea. Experiments were carried out to see if the brown shrimp is predating on juvenile turbot and flounder, and if so on which sizes, and if the brown shrimp prefers any of the flatfish species, and also to see if there is a difference between day and night in density of the shrimp, i.e. when the fish might be subjected to predation. The results showed that predation decreased with size for both turbot and flounder.
Demografisk sammansättning samt beteende hos medlemmar i panel
The use of marketing research panels are a more and more frequently used source of information for studies within many different branches. The purpose of this report is to investigate the demographic composition of panels and compare it with the population of Sweden, a possible change in behaviour of respondents, and if the source of recruitment is the cause of possible differences in study results. The study was commissioned by Norstats Linkoping office. Sources for the data material include Norstat?s recruitment process and their two main panels with different recruitment sources.
Effect of botanically diverse pastures on the milk fatty acid profiles in New Zealand dairy cows
Botanically diverse pastures are commonly used in New Zealand to reduce the ruminant environmental impact by reducing the methane production from the rumen digestion. In order to evaluate the effects diverse pasture species have on the milk fatty acid profile seventy-two lactating Friesian-Jersey crossbred dairy cows were used in a randomised block design with two replicates of six treatments. Six different pasture mixtures were fed at a daily allowance of approximately 15 kg DM/cow/day. The mixtures were categorised as either a simple or a diverse pasture. The simple mixtures all contained white clover with the addition of either a standard diploid perennial ryegrass (RG), a diploid high sugar ryegrass (HS) or tall fescue (TF).
Effekten av klimatförändringar påkontrollbehovet av åkerogräs
With a changing climate, we can expect higher temperatures and more precipitation in Sweden.As the temperature increases, new weed species are expected to migrate in from more southerlylatitudes, resulting in requests for new techniques for weed control. In addition, we might see agreater number of weed species and higher biomass production due to increased concentrationof CO2 in the atmosphere.Increased understanding of the biology of specific weed species will become more importantin future weed control. This will help to control the weeds more efficiently. Higher prices onpesticides and a public demand for reduced use of pesticides make growers more inclined to usemechanical weed control on a larger scale and to a greater extent prevent weed establishmentbefore sowing. A well-planned crop rotation is the most important preventive measure, whichmight also include delayed sowing, and dark harrowing and sowing.Research takes place on many levels within the weed area and several alternative methodsare being developed.
Klimatförändringar och dess effekter på ogräsfloran i Sverige :
Land management for food production is a fundamental human activity and one of the greatest challenges of the 21st century will be to increase the global food to accommodate a world growing to 10 billion or more people, while undergoing climate change. The increasing temperature and the current and projected increase in concentrations of CO2 lead to concern over possible impacts on agricultural pests. This assay is summarizing the knowledge of weeds in a changing climate in Sweden. Global warming and other climatic changes will affect the growth, phenology, and geographical distribution of weeds. The climate change will also affect the weed composition indirect by causing changes in the agriculture.
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.
Inventory and evaluation of Nairobi Animal Orphanage : focusing on routines and feeding, black-backed jackal, lion and patas monkey
This BSc thesis is an introductory step to the collaboration between the Swedish zoo Skansen and Kenya Wildlife Service (KWS). It constitutes of an inventory of the Nairobi Animal Orphanage (AO), a facility that cares for injured and abandoned wildlife species in Kenya. Through the cooperation with Skansen, the KWS will improve their management of the AO. The aim of the inventory and BSc theses is to evaluate the management of black-backed jackal (Canis mesomelas), lion (Panthera leo) and patas monkey (Erythrocebus patas) regarding their biological needs. The general enclosures, routines and feeding at the AO are also evaluated since they have a great influence on the management of captive animals.
Comparison of bird communities in stands of introduced lodgepole pine and native Scots pine in Sweden
The introduced lodgepole pine (Pinus contorta) occupies more than 650 000 hectares in Sweden. There are some differences between lodgepole pine and Scots pine (Pinus sylvestris) forests which could affect bird assemblages, for example differences in canopy density and ground vegetation. Birds were surveyed in 14 localities in northern Sweden, each characterized by one middle-aged stand of lodgepole pine next to a stand of Scots pine. The two paired stands in each locality were planted by the forestry company SCA at the same time and in similar environment to evaluate the potential of lodgepole pine in Sweden. In those 14 localities, one to three point count stations were established in both the lodgepole pine and the Scots pine stand, depending on the size of the area.
Beror KRAV-grisars ledanmärkningar på miljöfaktorer?
This project investigated how elevation and vegetation type influences variation in plant litter phenolic content and protein precipitation capacity among and within common plant species for two different vegetation types, heath and meadow, in a subarctic ecosystem in the Abisko region of northern Sweden. As nutrient availability generally decreases with increasing elevation as a result of decreasing temperature, I hypothesised that phenolic content would increase with elevation and be higher on the heath than the meadow. To test this, the total phenolic content and protein precipitation capacity was estimated in leaf litter from 13 species in both heath and meadow vegetation across an elevational gradient ranging from 500 to 1000 meters above sea level (m.a.s.l.) in the study region. The results showed that elevation and vegetation type both had a strong impact on both variables. Total phenolic concentrations decreased with elevation for the meadow, and were greater for the heath than the meadow.
Vägen till en framgångsrik utlandsetablering : en studie av Akzo Nobel Nippon Paint AB:s etableringsstrategier
Establishment can be described in many terms. This term is about a company that is establishing on the European market. For many companies, this can appear as a difficult, time- and resource taking process but to advance and develop it is not enough to have a good position on the Swedish market. The company Akzo Nobel Nippon Paint AB, which this composition is about, has taken the risk to leave the home country and explore the unknown. The process was careful and long-termed but also profitable.
Effects of palmitic and stearic acids supplementation on milk yield, composition and milk lipolysis in dairy cows
When facing the fact that high yielding dairy cows has an increasing energy requirements, the practice of adding lipid supplements such as concentrates rich in palm oil and/or palm oil industry by-products become more common. Palm oil containing high levels of C16:0 causes high levels of free fatty acids (FFA) which are linked to larger milk fat globules (MFG) which affect the reaction of lipolysis resulting in rancid flavour and processing problems. Instead of using palm oil, rapeseed oil rich in C18:1 C18:2 can be used. In order to evaluate the effect of
added C18:0 and C16:0 on milk lipolysis, 30 Swedish Red lactating dairy cows including 15 multiparous (MP) and 15 primiparous (PP) cows were randomly divided in three groups
resulting in 3 10 cow-groups (5 PP and 5 MP cows per group) and fed one out of three concentrate mixtures: control (C), a standard concentrate mixture with no fat added; palmitate
(P) as C plus the addition of palmitate methyl ester (10 % in DM basis); and stearate (St) as C plus the addition of stearate methyl ester (10 % in DM basis). Milk yield was registered, and milk samples were collected and analysed for milk composition, FFA content and size of MFG.
GIS-baserad habitatmodell för mindre hackspett, ett verktyg för att bevara skyddsvärda lövskogar inom Umeälvlandskapet :
Deciduous forests are, according to the National Environmental Quality Objectives, a priority area. Deciduous forests are rich in species and the occurrence of dead wood is an important factor for biodiversity. In order to identify valuable deciduous forests for bio-diversity, conservation needs good analyses and planning tools. Habitat models combined with geographic information systems can be used to study the spatial structure of suitable habitat. The Lesser spotted woodpecker (Dendrocopos minor) has been proposed as an indicator species for deciduous forests, since this species is highly specialized on insect larvae in dead wood and requires large areas of deciduous-rich environments.
Many riparian forest with high species richness and high nature conservation values are found along the Ume river in Umeå municipality.
Sköldpaddsdammen som en naturlig oas på Mallorca : en fallstudie
This study shows how to plan a pond with an ecosystem which although it will have turtles living in it will not need to be cared. I will also demonstrate how this pond would be designed to work in the natural landscape on Mallorca.
The background to the study is that I am interested to investigate how plants that we in Sweden are using as indoor plants are growing in their natural landscape and how to build a land-scape with them. The study highlights different cleaning-systems that can be used to clean a pond in a natural way. A comparison will be made between the conditions of an exterminated turtle-species which will live in this environment and a species that is easier to care for.
Klövviltets besöksfrekvens och bete i sydsvenska poppelplanteringar
Energy is an essential part of the society and for a sustainable future we need to use the energy resources in a sustainable way. The forest is Sweden?s most important resource for renewable energy and a higher production combined with shorter rotation periods (time from planting to clear cutting) can increase the access to energy. The tree genus poplar (Populus spp.) is interesting as energy resource as it has both high production and short rotation period.
But browsing ungulates are a major threat to the establishment of poplar plants and therefore the poplar plantations need to be fenced in today. To use fences is expensive and time consuming; this makes it interesting to find more cost-effective solutions where there is no need to fence.
The aim with this study was to look at the ungulates? occupation rate and browsing pressure in poplar plantations without fence.