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2172 Uppsatser om Identified species - Sida 13 av 145
Vad styr förekomsten av sälg och asp? : en studie av olika beståndstyper inom Hamra kronopark, Dalarna
Aspen (Populus tremula L.) and goat willow (Salix caprea L.) are two important tree species in the aspect of nature conservation. Due to the elimination of forest fires, a former negative attitude towards deciduous trees in forestry and a strong herbivore pressure, these tree species have been negatively affected during the last fifty years. The aim of this study was to investigate whether the occurrence of aspen and goat willow could be related to either human impact or to site properties, such as ground moisture and vegetation type. A side study included an inventory of a number of cyanobacterial tree lichens on aspen and goat willow in order to try to relate the occurrence of these lichens species to stand history and stand properties.
The study was performed in Hamra State Forest in northern Dalarna. Nature reserves were compared with stands in managed areas.
Stjälkröksvamp (Tulostoma brumale) : stora eller små individer?
The spatial population structure of the saprotrophic basidiomycete Tulostoma brumale was investigated at a site in south eastern Sweden. Sporocarps were mapped and collected, and somatic incompatibility tests between mycelial cultures cultivated from the sporocarps were used to identify genets. Calculations of the size and numbers of genets and their distribution were performed. The spatial distribution of the tested sporocarps and the identified genets are presented graphically in a grid. The total number of identified genets within the investigated area (1210 m2) was 27 based on 48 tested sporocarps.
En jämförelse av sitkagranens (Picea sitchensis) och den vanliga granens (P. abies) produktion :
Sitka spruce (Picea sitchensis) is a tree species that have its natural distribution along the
West Coast of North America, from Alaska in the north to northern California in the south.
Sitka spruce is a typical coastal tree species that can reach heights up to 85 meters and occurs
in single pure as well as in mixed stands.
The main purposes of this study were to describe the Sitka spruce growing characteristics and
the volume production in comparison to spruce (Picea abies). The possibility to predict future
volume production by using prognosis tools designed to be used on spruce were also studied.
The material that has been used in this study are permanent sitka trials established by the
Faculty of Forestry fixed Sitka trials and also material gathered in this study.
A literature study was also carried out in order to determine the Sitka spruce growing
characteristics.
Sitka spruce has a high adaptation and a high volume production on a broad scale of soil
types. The tree species is a pioneer species that has a fast early growth and in combination
with sharp needles it is less susceptible to animal browsing than spruce. The factor that is the
single most limiting factor for where the Sitka spruce can be planted is frost. This factor can
be limited by using plant material with a well-suited provenance.
According to the literature, the Sitka spruce has an average total volume production that is
between 20-40% higher than spruce.
Productivity of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) in coastal areas of northern Sweden
Productivity of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) was
studied on 12 sites in coastal areas of northern Sweden. On each site, sample
plots were placed in adjacent Norway spruce and Scots pine stands with similar
ages in between. Basal area, tree height, Site Index, volume production,
simulated maximum mean annual increment (MAImax) and tree vitality were
compared for the two species. Average basal area at the time of measurement
was 30.4% larger for Scots pine stands than for Norway spruce stands. The
difference between the two species in basal area increment during the last 10
years was related to stand age.
Vad innebär digitalisering av kulturarvet? En ideologianalys av tre svenska digitaliseringsprojekt
This Masters Degree thesis aims at giving an answer to what underlying ideologies are at work in digitizing our cultural heritage. Other questions to be answered are who are benefiting from a digitized cultural heritage and who are not, and what different opinions about digitizing our cultural heritage can be identified. Two studies are made in this thesis, one of Swedish political documents that concern digitizing our cultural heritage, libraries, museums and archives, and the other one is a study of documentation of three Swedish digitizing projects. In the first study three different, but closely associated ideologies are identified, namely a preserving, b giving access and c a mixture of both, and these are shown in a model. In the second study this model is then used to identify the ideologies of one project from each sector of the so called ABM-sector Archives, Libraries and Museums.
Bok- och grankonkurrens i Sydsverige - markegenskaper och naturlig föryngring :
In southern Sweden, beech (Fagus silvatica) and spruce (Picea abies) are two species with similar demands on soil properties. With increased global warming and high acid deposition the future may bring larger areas were the two species are overlapping, competing for the same soil. The aim of this study was to compare spruce and beech concerning distribution, cultivation and soil properties. From available data comparisons were made between spruce and beech forests in Sweden. Soil analyses were made on samples from beech forest in southern Sweden, with and without natural regeneration of spruce.
Inventering av flodpärlmussla i Fylleån norr om Gyltigesjön
Freshwater environments are threatened worldwide, of which many of the species associatedwith freshwater. In 2014, 243 freshwater mussels were on the international Red List. One ofthem is the freshwater pearl mussel, Margaritifera margaritifera, which because of itscomplex life cycle can be counted as an indicator of whether a stream is worth protecting. It's since the early 1900's in decline throughout their range. Sweden is counted as a core area which is why we have not only a national but an international responsibility to conserve the species.
Effects of brown bear (Ursus arctos) odour on the patch choice and behaviour of different ungulate species
The return of large predators to regions where they were previously extirpated has created a need for knowledge about their effect on prey species, not only their lethal but also their behavioural or risk effects. In this study the behavioural risk effects of brown bear (Ursus arctos) were tested on fallow deer (Dama dama), roe deer (Capreolus capreolus), red deer (Cervus elaphus), moose (Alces alces) and wild boar (Sus scrofa). This was done by using
patches of fur to simulate the presence of the novel predator (brown bear), a novel nonpredator (reindeer (Rangifer tarandus) and no fur as control. These three treatments were then compared. The response variables measured were increased vigilance, decreased feeding time
and change in patch use.
Vattensork och åkersork - skadegörare i svensk fruktodling
There are two species of voles that cause damage in Swedish fruit production: the water vole (Arvicola terrestris) and the field vole (Microtus agrestis). Both species make the most damage during the winter season. The water vole makes subterranean burrows and cause serious damage by gnawing on the tree roots. The field vole seldom makes burrows and gnaws the bark at the base of the tree trunk. In recent years there have been several reports about increasing vole damage.
ABC-kalkylering i praktiken
This thesis is based on an assignment from a unit within an international group manufacturing industrial products. The purpose of the thesis is to analyze and suggest ways to improve the cost accounting system in use at the unit. The main source of empirical data has been interviews with employees. The theoretical framework is based on a comparison between traditional/standard costing and activity-based costing (ABC). The cost accounting system in use is described in detail and classified as a traditional/standard cost accounting system.
Environmental variables determining the occurrence of the red-listed Carbonicola anthracophila and C. myrmecina in boreal forests
The global biodiversity loss is mainly due to human activities such as an intensification of forestry. Boreal forest ecosystems in Fennoscandia are characterized by disturbances such as forest fires, storms and floods. However, industrial forestry practices suppress forest fires and change the landscape, leading to a loss of habitats and associated species. Particularly lichen species with slow adaptation abilities and a strong substrate specificity face an extinction debt in boreal forests since their substrates are long-lived but no longer created. In this study the species-substrate relationship of two red-listed forest-fire dependent lichen species Carbon-icola anthracophila and C.
Förekomst av kontaminanter i importerad fisk : en litteraturstudie
A literature review of contaminants; cadmium, methylmercury, dioxins, and PCB, for eleven different fish species (Greenland halibut, gilt headed bream, sea bass, wolffish, hoki, ocean perch, angler, Nile perch, pangasius, red snapper and tilapia) that were selected in concurrence with the National Food Administration. The result can be used by the National Food Administration to gain further knowledge about the different fish species to be able to continue to give advice to varied risk category and the public. The gilt headed bream and sea bass were the only fishes whose values for mercury exceeded the limit of 0,5 mg/kg (EU Reg. 1881/2006). In the angler, Nile perch and pangasius the mean value of mercury didn?t exceed the limit, however in some individuals the mercury content did exceed what is allowed.
Kognitionsforskning i djurhållningen: grisars kognition och dess tillämpning vid slaktsvinshållning
Pigs are often mentioned as relatively intelligent animals when compared to other nonhuman species. Despite this knowledge, the vast majority of pigs are kept under conditions that lack opportunities to satisfy their cognitive needs. Therefore, a need to evaluate the present scientific studies about pig cognition was acknowledged, in order to evaluate to what extent the knowledge is applied in the husbandry of finishing pigs. If a considerable lack of application was determined, suggestions about how to use the obtained information to improve pig welfare were also to be made.
A synthesis of the present literature was made, and it could be concluded that a considerable amount of studies had been carried out in the present area. The pigs of today appear to have the same behavioural and cognitive needs as their ancestor, the wild boar.
Tillämpning av lättrörliga systemutvecklingsmetoder - en studie av systemutvecklingsprocessen i en ad hoc-krati
Due to fast growing and rapid changes in markets today, most of the organizationsthat are trying keep up with these changes have a high demand for software that areof high quality and comes with a low price. To meet these goals software companieshave to implement new methods to develop software that are suited for rapidchanges. The concept of agile methods can fulfill this need. Our purpose with thisthesis was to investigate how well agile methods could be applied in organizationsthat could be identified as adhocracies. A case study was conducted in anorganization which we could identify as an adhocracy.
Sker rengöring av ögon, antenner och mun hos Odonata : Coenagrion larver med hjälp av borsten på framben och fötter?
Dragonflies are fascinating. The larvae stays larvae from a couple of weeks up to 5 years, it depends on the species (Hansen, 1981). The temperature, nourishment and time of the year also play a role for the growing factor for the larvae. Both Sahlén (1985) and Begon a.o (1990) say so. My report contains information about the branched setae on the front legs from the family damselflies (Zygoptera) and the species Coenagrion.