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745 Uppsatser om Threatened species - Sida 29 av 50

Restaurerade ängs- och betesmarker : restaureringseffekten på växter och insekter

Semi-natural grasslands have a high biodiversity and host ecologically and economically valuable ecosystems and species. Restoration on these types of land is often done by removing trees and scrubs, mowing, grazing, changing the soil by removing nutrition or changing the structure of the ground. Another way of restoration is planting seeds of common grassland plants. By comparing 18 scientific publications I investigated if the restoration was affecting the plants in a positive way and if the effect was similar for insects. By comparing the publications, time seemed to have an important effect on insects. They needed time to recolonize restored areas.

Vermicompost for reduction of vegetable waste - and a possible means to produce fish feed in aquaponic systems?

Aquaponics is a food production system consisting of a consecutive cultivation of plants and aquatic animals, fish or shellfish, in recirculating water. The plants feed on the nutritious effluents from the fish tank and bacteria converts ammonia from the fish tank into nitrate that is absorbed by the plants. The plants receive nutrition and the fish gain purified water. The environmental impact of the production of fish meal and fish oil used in conventional fish feed includes a large consumption of fossil fuels with subsequent carbon dioxide emission. The aquaponic system can be made environmentally sustainable and self-supporting if supplemented with a vermicompost/vermiculture for the production of worm protein as a fish feed. Vegetable waste from the hydroponic part of the system can be reused as worm feed in the compost and the protein rich worms can be harvested, dried and grinded and brought back to the aquaculture as fish feed. As a first step in this direction, I have investigated the effect of recycling of vegetable waste in vermicomposts on the growth and number of earthworms (this was evaluated after harvesting). The hypotheses were that earthworms can be cultivated in the vegetable waste and that by adding manure to the vermicompost it is possible to obtain a nutrient content adequate to support a continuous worm harvest, in other words create a vermiculture. Eisenia fetida and Dendrobaena veneta were grown in 20 L bins containing peat mixed with either poultry or cattle manure. The proportions were 70% peat and 30 % manure. Discarded plant parts from lettuce cultivation was added to the vermicomposts (35 g per week) and water was supplied with 0.8 L per week.

Undersökning av självspridning av contortatallen i norra Sverige

Over the past 40 years 600 000 ha of lodgepole pine (Pinus contorta ssp. latifolia (Engelm.) Critchf.) has been planted in Sweden (280 000 ha on SCA's forest land alone which represents about 15% of the company's total forest land area). In the early 70's SCA situated a number of experimental stands in order to investigate different aspects of the exotic tree, primarily growth rate. To be able to compare the two species plots with scots pine (Pinus sylvestris L.), this species was also planted at the same time and under the same conditions. A number of questions should always be raised when exotic species are introduced in an ecosystem. Invasiveness, the pathogen situation and purely ethical issues should be discussed.

Hur mycket frö sprids från Pinus contorta? : kottproduktion, serotinitet och frökvalitet i relation till beståndsålder i södra Norrland

Contortatall (Pinus contorta ssp. latifolia) började planteras storskaligt i Sverige runt år 1970 men det dröjde till 1987 förrän Sverige lagstiftade begränsningar för hur den fick användas i skogsbruket. Detta gjordes bland annat på grund av att det saknades information om dess spridningsförmåga. Contortans spridningsförmåga i Sverige är fortfarande okänd och lagstiftningen är densamma. För att kunna beräkna spridningsförmågan och i förlängningen den potentiella etableringsframgången behövs kännedom om contortans fröproduktion i Sverige.

Fodertillgång och stereotypa beteenden under natten hos Asiatisk elefant (Elephas maximus)

Animals in zoos live in more barren environments than their conspecifics in nature. In nature, elephants spend more than 75 % of the day foraging and have been observed lying down two hours during night. Stereotypies are common in many different species in zoos. Stereotypic behaviors may constitute up to 50 % of the daily activity budget of zoo elephants. Modern zoos try to reduce stereotypic behaviors by means of environmental enrichment.

Kan förändringar i bottenfaunan påvisas två år efter en bäckrestaurering?

The aim of this work is to analyze if a change in the benthic community can be detected two years after a restoration of a small stream. The samples were taken in a small stream at Tinnerö Eklandskap just south of Linköping. In addition to the restored area, two reference sites upstream and downstream of the restored area were sampled to compare to the restored site. The method used for sampling of benthic fauna in the stream was kick sampling. ASPT, Berger-Parker and Renkonen-indices were used to find out if there was any difference between the reference areas and the restored area.

Klöver i ensilage till suggor - effekter på reproduktion och produktivitet

The weather has been extremely rainy the last summers in Sweden. Because of the rain, a lot of harvested straw has been lost since it was too wet to store. When the pig producers couldn?t get enough straw to use as bedding, an alternative was requested. Silage is a realistic alternative to straw but since silage often contains clover, it may not be suitable to use in pig production since clover is rich in phytoestrogens.

Timmerkvalitet hos björk i blandskog med gran

Birch is the dominant deciduous tree species in Sweden but only 16 % is found in pure birch stands. The majority of the birch (51 %) is to be found in conifer dominated stands. Swedish forest land comprises approximately of 23 % mixed stands and one problem is that for mixed stands there are few management recommendations. The underlying aim of this thesis was to study the management of mixed forest stands of spruce and birch to achieve good timber quality of birch. The study was based on a literature study and measurement in a field experiment launched in 1998 by the Swedish University of Agricultural Sciences (SLU).

Inte var väl det så synd? Om församlingspedagogers syn på synd och hur de hanterar ämnet i barn- och konfirmandgrupper

The ambition of this paper is to study the construction of the categorization between ?us? and ?them? in a religious minority, represented by Jehovah?s Witnesses and a nationalist political party, represented by the Swedish Democrats. This will be done by a discursive psychology analysis of their official publications on each group?s website. By a deductive study using Henri Tajfel?s Social Identity Theory trying to disclose the psychological processes; social categorization, social identity, social comparison and psychological distinctiveness.

Feline Odontoclastic Resorptive Lesion (FORL) : en morfologisk beskrivning

Feline Odontoclastic Resorptive Lesions (FORL) is a painful disease that affects feline teeth and that is increasing in prevalence. The ethiology is still rather unknown. However, research on the ultra structure of the feline tooth may help us understand why FORL is so prevalent in cats and not in other species. Since the ethiology is still unknown, there is yet no profylaxis. The pathogenesis is rather well known; the hard structure of affected teeth gradually undergo odontoclastic resorption and resorptive lesions are often partly replaced with bone- or cementum-like tissue.

Rousseau och Voltaire : Två helt (o)lika filosofers filosofier

This thesis has two purposes: (1) to analyze the emptiness in Blodbok by Christine Falkenland, and (2) to analyze my own reading of the same book. I have chosen to focus on how emptiness is expressed through the body, the language and the place in Blodbok, because of the deep impact these seem to have on the emptiness. The thesis discusses what kind of emptiness that is described, what it does to me as a reader, and how it is connected to other works by Falkenland. Cultural politics of emotions by Sara Ahmed, Uses of literature by Rita Felski and Pouvoirs de l?horreur by Julia Kristeva together form the theoretical framework.Blodbok is a poetry collection, about the loss of a mother.

Cultivation of Chlorella vulgaris in nutrient solution from greenhouse tomato production : a possibility to reduce nutrient levels and produce commercially interesting metabolites

The idea of using algae in different areas and exploring its possibilities is nothing new. Already in the early 1950s microalgae was explored as a possible food resource because of its high protein content. Lately there has been an increased interest in its potential for industrial use. Wastewater treatment is a possible use of algae since the algae grow well on the nutrients present in the water. This offers the possibility to grow algae for nutrient reduction and use the biomass for energy or animal feed since many alga species has a good nutritional value. Approximately 800-1000 m3 water is applied per 1000 m2 of greenhouse area during one season in a tomato production.

Det nazistiska hotet i Tidens spegel 1932-1939 : Arbetarrörelsen i spänningsfältet mellan demokrati och diktatur

The purpose of this study is to examine the effect the Nazi threat had on the swedish labour movement between 1932 and 1939 and to enrich what kind of pre-understanding they had about the fall of the Weimar Republic and the upcoming and effects of the Third Reich.Brought by the development in Germany, a debate and struggle took place in the Social Democratic journal Tiden over the meaning of concepts and there ability, in the hands of demagogs, to overthrow democratic structures. The concept of socialism and its concepts attribute play a major part in this investigation. By establishing fields of tension such as - nation vs internationalism, socialism in theory and in practice, political democracy vs evolved democracy and the diverse principles of neutrality, the first principle meaning the defending of national boarders, the other meaning not only defending your own country but taking an active part in defending democracy in the world - I was able to observe the movement and change of concepts within this fields. The result showing that the concept of socialism and near related attributes, in the hands of national socialists had undertaken a wast change of meaning, which applied in the Swedish debate threatened to undermine the power and force of the Social Democrats applied in the political discourse in Sweden. To defend itself and strengthening the Social Democratic hegemony as well as maintaining the goal of evolved democratic expansion, they were forced to win the confidence and votes of the middle class.

Vegetationsutveckling och mänsklig aktivitet under äldre Stenålder vid Döudden, Arjeplog kommun :

The landscape in the interior of Norrland has undergone dramatic changes since the deglaciation as a consequence of faultings, earthquakes and tilting of the landscape westwards. Archaeological investigations along former shorelines by the use of models of isostatic land uplift, have revealed many Mesolitic settlements in northern Sweden. Döudden, in the county of Arjeplog, has been investigated by archaeologists that identified settlements from 5200 BC. The objective of this study was to analyse the history of the vegetation and if the vegetation showed traces of human activity during early Holocene, by pollen analysis. The results indicate that the area had an established vegetation c.

Näsnarens framtid i ett näringsstatusperspektiv

Eutrophication has been a problem in aquatic systems for a long time. It is well known that the key nutrient to control the eutrophication process is phosphorus. Lately, it has been possible to reverse the process and recover lakes from eutrophication.During a long time Lake Näsnaren in Katrineholms kommun, Södermanland, has been exposed of a large amount of phosphorus from the city's wastewater. The lake has a great value as a habitat of rare species but also a high recreation value for people living in Katrineholm and Södermanland. Lake Näsnaren is situated in a Natura 2000 area.

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