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813 Uppsatser om Didactical indicator species - Sida 27 av 55
The effect of arginine on root system development in Norway spruce (Picea abies L. Karst) somatic embryos
The demands for higher production yields and better quality materials from the forests are increasing globally. Tree breeding programs are directed to meet the future demands on forests. In order to capture the full benefits from the breeding programs, clonal propagation is necessary. For most conifer species, somatic embryogenesis (SE) is the only available option for large scale clonal propagation of Elite clonal material. For Norway spruce (Picea abies L.
Mjölkkors behov av att ligga och att sova
The aim of this literature review was to investigate whether the modern dairy cow has the time she needs to lie down and to sleep and what deprivation of these behaviors could lead to. Current research seems to agree on the fact that sleep is essential but there is no uniform explanation of the function of sleep, even though there are many theories. It is known that sleep has an important impact on the immune system and that sleep is increased in case of an infection. Sleep deprivation causes many negative effects including reduced function off the immune defense, increased metabolic activity, malnutrition and increased heart rate. It has also been found that deprivation of sleep could cause increased mortality.
Effekt av ras och säsong på nötkreaturs avbetningsgrad av konkurrenskraftiga betesmarksväxter :
Grasslands which have been actively managed for a long time and which in modern times have not been subject to cultivation such as fertilization are called semi-natural grasslands. These rare and species-rich areas hold an ecological, biological and historical value and if the management stops these areas will likely diminish. More effective agricultural systems and a declining number of grazing animals have in Sweden, among other countries, made semi-natural grasslands less valuable as foraging areas. Shrubs and fast growing plants rapidly colonize abandoned semi-natural grasslands, threatening biodiversity.
The objective of this experiment was to determine the effects of breed and season on diet composition, with special reference to four competitive species found in wet areas ? in cattle grazing heterogeneous semi-natural grasslands ? and thereby contribute to improved management of these areas.
Skogsbruksplanen - ett hjälpmedel i vattenförvaltningsfrågor? : en intervjustudie
After the mandatory rules for clearing was removed in 1994, the clearing area has increased in Sweden. After the storms Gudrun and Per, the areas became planted with new plants, mainly spruce, but also other tree species. Storm areas are now being invaded by naturally rejuvenated birch in the tilling tracks. Since the birch often is initially growing faster than the spruce it is inhibiting the growth and is also damaging the spruce.
The purpose of this thesis is to study the new brush saw with chain and compare it with the conventional clearing saw, mainly in terms of performance and ergonomics. The results show that the new brush saw with chain is very good in almost all clearing operations compared to the conventional clearing saw.
Can increased activity recorded with help of activity monitoring sensor indicate an upcoming calving?
The purpose of this study was to find out if motion movements, e.g. number of lying bouts and lying time with a registered activity monitoring sensor can detect an impending calving and thereby be used as a measure and an indicator for an upcoming calving. For this, automatically step sensors were used and were attached to one of the cows? hind leg. The sensor registered the individual step and movement activity of the cow.
Pallaskattens (Otocolobus manul) beteende i två djurparker - påverkan av hägndesign och miljö
The Pallas cat is a small cat living in central Asia. The cat is approximately the size of a domestic cat but the Pallas cat is more stocky build and has a much thicker fur that enables the cat to live in a climate with temperatures plummeting to -50°C. The thick fur is one of the reasons this cat has been a popular game for hunters in the past. Nowadays there are other threats to the Pallas cat. One of the major threats today is the reduction of food sources.
Förekomst & kostnad av kapsprickor i stormaskadad skog
The aim for this study where to investigate the frequency of cutting cracks in saw timber harvested in the storm-damaged forests in regions where the storms Hilde and Ivar hit. The idea for this work came from one of the region?s biggest actors, SCA Skog and Jämtlands district. The purpose where to find out how big proportion of the saw timber that contains cutting cracks, their financial cost in lost wood value and also give advice and suggestions on how to work against the frequency of cutting cracks.
For the field-study some guidelines where used to make sure that the samples were taken under the same conditions, they were:
? The field-study must be performed under harvesting of storm-felled forest, which are horizontal/inclined trunks.
? The averaged sized tree will make it possible to harvest saw timber.
? The trunks can?t be root cut.
A methodology called in Swedish ?Trissmetoden? was used because it is the most frequent used methodology in earlier performed studies and the only one that can be used I field.
Under the field-study data were collected from 570 saw timber logs, 30 logs from each one of the tested harvesters.
Do 25 years old skid tracks restrict growth and survival? : a study on growth conditions for the planted regeneration in a rainforest rehabilitation project
The rainforests of the world are important not only to the countries in which they grow but to the world as a whole. They influence oxygen and water circulation as well as carbon sequestration which in turn affect global radiation and global warming. The forest also have great value and in Malaysia as in many other tropical countries large volumes are harvested which leaves great areas of degraded forest with little growth and biological diversity. Due to their low financial value these forests are often transformed and used for other purposes than forestry such as oil palm plantations.
The trees are often transported out of the forest using large bulldozers. They are heavy which causes compaction of the forest floor and during transport the top soil layers are moved to improve mobility.
Välfärd i ekologisk och konventionell grishållning :
Organic animal husbandry has received a lot of criticism lately. The aim of this literature review was to examine if the rules and principles of organic pig farming give better or worse welfare in comparison to the conventional systems in Sweden. Health, physiology and behaviour have been used as indicators of welfare in this study. This is due to the importance of using more than one indicator in welfare assessments. Studies have shown that organic pigs have more remarks on joints when slaughtered, but these remarks can be reduced by vaccination against erysipelas.
Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt :
Reindeer husbandry and Forestry are both area related industries and will in big extent use the same lands. Conflicts often arise because of that the industries have different interests. Many of the activities done by the forestry influences the reindeer husbandry in an undesirable way, simultaneously as the reindeer husbandry activities can have negative consequences for the forestry. One such forestry activity is fertilization.
It was during the 1960´s forest fertilization began to be practiced and the reason was that the increase in growth that the fertilization gave could be able to cover for the future shortage in wood many feared.
During the 1970´s when the fertilizing activities were most intensive about 200 000 ha was fertilized annually.
Hur bokskogslagen blev till ? konflikter och lösningar 1964-1974
During the early Middle Ages beech forests (Fagus sylvatica L.) spread out over large parts of southern Sweden. They had a crucial role in human survival for hundreds of years. For various reasons, the beech forest area has decreased since the 1600s. Spruce planted on former beech forest land was the primary reason for the decline during the second half of the 1900s, which made many worried about the future of the beech forests and led to a beech forest act in 1974. This study describes the background to the beech forest act based on parliamentary official documents.
Volume and taper equations for Sitka spruce (Picea sitchensis (Bong.) Carr.), Norway spruce (Picea abies (L.) Karst.) and White spruce (Picea glauca (Moench) Voss) in Iceland
The aim of this study was to evaluate different types of volume and taper equations that can be used to predict single-tree stem volume and stem diameter at any given height along the tree stem for plantation grown Sitka spruce (Picea sitchensis (Bong.) Carr.), Norway spruce (Picea abies (L.) Karst) and White spruce (Picea glauca (Mounch) Voss) in Iceland. A number of published tree volume equations were tested and modified to predict the total stem volumes over bark but three logarithmic equations were taken for more in-depth analysis. Three taper equations were tested. Two variable-exponent equations (Kozak 1997, Kozak 2004) and one exponential equation described by Biging (1984). Data from a total of 617 sample trees were used in this study, collected from stands in various parts of the country and present different types of stands growing in different soil types and cover most of the site conditions suitable for forestry in Iceland.
In search for sustainable alternatives to lawns : connecting research and landscape design
A large part of Sweden?s green, urban landscape is covered by lawns. Approximately 80 000 ha of maintained grass lawns are part of public courtyards, schoolyards, parks, golf courses, sport fields and traffic environments. Beyond this figure, the lawn is also an essential element in most private villa-gardens. Lawns have become a universal phenomenon through the dispersion of landscape aesthetics from the Western world.
Samiskt skogsutnyttjande, dimensionsavverkningar och naturvärden : skogshistorisk analys i block 5, Pakko kronopark i Norrbotten
In order to understand the human impact on today?s remaining ?virgin? forest and to develop sensible management strategies for future reserves, it is necessary to know how these forests have developed. This knowledge can be gained by using forest history analysis. here are large areas of forests still untouched by modern forestry in the mountainous region in the county of Norrbotten. These forests are highly interesting study objects from an ecological and historical point of view.
Nätmobbning Om relationen mellan traditionell mobbning och nätmobbning i grundskolan
This study investigates the relation between cyberbullying and traditional bullying (in school). In previous research it has been argued that one should separate cyberbullying and traditional bullying both in definitional and measurements issues. However, in Swedish school, there are no marked differences between the two forms of bullying, teachers are responsible to prevent them both. The research is based on 3925 students in years 3-9 (1950 girls and 1975 boys) in 19 schools in the Gothenburg region and two from the Stockholm region. The students have taken a digital survey at school, regarding both traditional and cyber bullying.