The thesis deals with the preparation, creation and evaluation of an informatics competition for pupils of primary and secondary schools, called Informatics Beaver. The work also includes a summary of simile existing contests on informatics. Furthermore, it seeks to convey and clarify the technical and organizational problems associated with the preparation and conduct of the competition.

In der vorliegenden Bachelorarbeit wird die Notwendigkeit, Renaturierungsmaßnahmen für Auenbereiche der Gewässer 2. Ordnung durchzuführen, mit der Thematik der fortschreitenden Verbreitung des Bibers (Castor fiber L.) in einer kombinierten Herangehensweise bearbeitet. Ziel ist es ein Flächenkonzept zu erstellen, welches, als Teil des proaktiven Bibermanagements des Landkreises Mittelsachsen, auf geminderte Konfliktpotentiale in den ermittelten Vorrangflächen für Auenrenaturierung abzielt. Dabei sollen die Ansprüche von C. fiber an den potentiellen Lebensraum und seine aktiv landschaftsgestaltende Lebensweise ebenso berücksichtigt werden, wie anthropogene Nutzungsansprüche. Der Biber soll hierbei durch seine herausragenden Fähigkeiten als Renaturierer und Schlüsselart der Biodiversität gezielt auf diesen Flächen Raum für sein Wirken finden. Mittels einer eigens erstellten Methodik konnte die Flächenanalyse mit dem Programm Quantum GIS erfolgreich durchgeführt werden. Im Ergebnis werden 270 Vorrangflächen für Auenrenaturierung durch den Biber in Mittelsachsen präsentiert. Diese Flächen befinden sich verteilt im gesamten Untersuchungsgebiet und sind in nahezu jeder Gemeinde vorhanden. Eine anschließende Bewertung der Gebiete wurde bezüglich der Habitateignung für eine Besiedlung durch Castor fiber und der naturschutzfachlichen Biotopaufwertung der betroffenen Flächen vorgenommen. Sie stellt die Priorisierung für deren Umsetzung, beispielsweise im Rahmen von Naturschutzmaßnahmen, Einbezug in Regionalplan der Landschaftsentwicklung oder Kompensations- und Ersatzmaßnahmen, dar. / This bachelor thesis focuses on neccesary renaturation measures in meadow areas of second grade rivers and the ongoing distribution of the european beaver (Castor fiber L.) in a combined way. The main objective is to establish an area-concept, which is serving as a part of the proactive beaver management in the administration district Mittelsachsen aiming to reduce the potential of conflicts on the demanded areas. On the one hand, requirements of C. fiber on his potential habitat has to be fulfilled and his activly landscaping way of life should be accepted in this regions. On the other hand human-caused beneficiary claims have to be considered with the same importance. Nevertheless the fundamental approach is to give the beaver the opportunitiy to use his outstandig abilities in serving as a renaturater and key-species for biodiversity in this areas of interest. The project is carried out with the program Quantum GIS by using a self-created method of area-analysis and -assessment. In this way 270 potential areas for meadow renaturation measures through the beaver could be succesfully analysed. Those can be found spread all over the area of interest in Mittelsachsen. The following area-assessment is based on the grade of habitat-suitability for the beaver and it’s potential for an enhancement in a conservational meaning. Consequently one can judge the demanded areas according to their priorisation for measures like inclusion in compensation and substitute measures, regional landscapeplans or other measures of natural conservation.

In der vorliegenden Bachelorarbeit wird die Notwendigkeit, Renaturierungsmaßnahmen für Auenbereiche der Gewässer 2. Ordnung durchzuführen, mit der Thematik der fortschreitenden Verbreitung des Bibers (Castor fiber L.) in einer kombinierten Herangehensweise bearbeitet. Ziel ist es ein Flächenkonzept zu erstellen, welches, als Teil des proaktiven Bibermanagements des Landkreises Mittelsachsen, auf geminderte Konfliktpotentiale in den ermittelten Vorrangflächen für Auenrenaturierung abzielt. Dabei sollen die Ansprüche von C. fiber an den potentiellen Lebensraum und seine aktiv landschaftsgestaltende Lebensweise ebenso berücksichtigt werden, wie anthropogene Nutzungsansprüche. Der Biber soll hierbei durch seine herausragenden Fähigkeiten als Renaturierer und Schlüsselart der Biodiversität gezielt auf diesen Flächen Raum für sein Wirken finden. Mittels einer eigens erstellten Methodik konnte die Flächenanalyse mit dem Programm Quantum GIS erfolgreich durchgeführt werden. Im Ergebnis werden 270 Vorrangflächen für Auenrenaturierung durch den Biber in Mittelsachsen präsentiert. Diese Flächen befinden sich verteilt im gesamten Untersuchungsgebiet und sind in nahezu jeder Gemeinde vorhanden. Eine anschließende Bewertung der Gebiete wurde bezüglich der Habitateignung für eine Besiedlung durch Castor fiber und der naturschutzfachlichen Biotopaufwertung der betroffenen Flächen vorgenommen. Sie stellt die Priorisierung für deren Umsetzung, beispielsweise im Rahmen von Naturschutzmaßnahmen, Einbezug in Regionalplan der Landschaftsentwicklung oder Kompensations- und Ersatzmaßnahmen, dar. / This bachelor thesis focuses on neccesary renaturation measures in meadow areas of second grade rivers and the ongoing distribution of the european beaver (Castor fiber L.) in a combined way. The main objective is to establish an area-concept, which is serving as a part of the proactive beaver management in the administration district Mittelsachsen aiming to reduce the potential of conflicts on the demanded areas. On the one hand, requirements of C. fiber on his potential habitat has to be fulfilled and his activly landscaping way of life should be accepted in this regions. On the other hand human-caused beneficiary claims have to be considered with the same importance. Nevertheless the fundamental approach is to give the beaver the opportunitiy to use his outstandig abilities in serving as a renaturater and key-species for biodiversity in this areas of interest. The project is carried out with the program Quantum GIS by using a self-created method of area-analysis and -assessment. In this way 270 potential areas for meadow renaturation measures through the beaver could be succesfully analysed. Those can be found spread all over the area of interest in Mittelsachsen. The following area-assessment is based on the grade of habitat-suitability for the beaver and it’s potential for an enhancement in a conservational meaning. Consequently one can judge the demanded areas according to their priorisation for measures like inclusion in compensation and substitute measures, regional landscapeplans or other measures of natural conservation.

Bävergäll har använts som läkemedel i över 2500 år, både inom folkmedicin samt skolmedicin.  Inom läkekonsten kallas bävergället ofta castoreum och det är baserat på det torkade innehållet i s.k. bävergällpungar, vars starkt luktande sekret är avsett för bäverns revirmarkering. I denna kvalitativa studie undersöks bävergället utifrån ett medicinhistoriskt perspektiv och fokus ligger på Sverige fr.o.m. 1600-talet t.o.m. 1900-talets början. Denna uppsats berör bävergällets behandlings- och beredningsformer, samt varifrån man fick tag på det och vad det kostade. Uppsatsen ger en bred bild av bävergället genom historien och bävergällets mångahanda användningsområden som innefattar allt ifrån tandvärk till epilepsi. Dock var det särskilt vanligt i behandling mot olika kvinnosjukdomar såsom hysteri.  Bävergäll var ända in på 1900-talet ett officiellt läkemedel på svenska apotek och det var ett så eftersökt läkemedel att den stora efterfrågan kom att leda till bäverns utrotning i Sverige på 1870-talet. / Castoreum have been used as a drug for over 2500 years in both folk medicine and school medicine. It is based on the pungent smelling content of specific pouches of the beaver. In this study the medical use of castoreum is examined, with a focus on Sweden from the 1600s to the early 1900s. The essay describes in which ways castoreum was used as a treatment and in which forms. It tells from where you got the castoreum as well as how much you had to pay for it. This essay also presents castoreum throughout history and its wide application that includes a broad spectrum from toothache to hysteria. Castoreum was well into the 1900s an official drug at Swedish pharmacies, and it was such a sought-after drug that the high demand led to the extinction of the beaver in Sweden in the 1870s.

The semiaquatic mammals - amongst them the beaver Castor fiber - are inhabitants of the land-water-ecotone, which is characterized by length and low depth.Due to specific adaptations to their habitats, semiaquatic mammals are highly dependent on the specific structures and resources of the ecotone riverbank. Anthropogenic influences on the ecotone riverbank often cause destruction of the resources that leads to a decrease of structural diversity.Being a primary consumer, the beaver mainly uses the water as a medium for locomotion and escape. The equipment of the riverbank, mainly the bankside vegetation, is of great importance concerning foraging. The presence and the quantity of certain biofacts like feeding or cutting places and scent mounds give a hint on the value of different structures and resources of the bankside with regard to certain modes of behaviour. They also give information on different qualities of the used and unused parts of the bankside.Biofacts of beaver-activity were recorded along 20 km of riverbank during a five-year-period. The results of the statistical analysis show that beavers - concerning species-specific mode of behaviour - prefer certain riverbank structures. Biofacts and near-natural structures such as steep bank, riparian forest and willows correlate significantly positive whereas biofacts and anthropogenic structures as slope, farmland or absence of woody plants show significantly negative correlation. There is a strong connection between the number of biofacts - that is use of the riverbank or slope - and structural diversity. Based on these results, an eco-ethological model has been developed which makes it possible to predict behaviour in dependence on the specific structures and resources of the banks and slopes of anthropogenic influenced streams.

The 1994 Beaver Mountain fire ignited the canopies of subalpine fir, Abies lasiocarpa, and spread ground fire into adjacent Douglas-fir forests, Pseudotsuga menziesii var. glauca. Despite shorter flight seasons due to lower annual temperatures and persistent snow, the Douglas-fir bark beetle, Dendroctonus pseudotsugae Hopkins, attacked a range of moderately fire-injured host conifers. Logistic regression models illustrated that in 1995 associated bark beetles selected large diameter Douglas-fir with 60-80% bole char, 60-80% crown volume scorch, and 50-70% probability of mortality due to fire. In 1996 beetle preference shifted to smaller diameter trees with lighter fire injury. Tree size was less significant for predicted attack in 1996 because most large fire-damaged conifers were colonized by beetles in 1995. Beetle populations did not reach outbreak proportions outside the fire boundary, but 53 green trees were also infested in 1997 along the burn perimeter. Log linear tests conducted to quantify beetle emergence supported conclusions that beetles were not only attracted to mature, moderately fire-weakened conifers, but also produced greater brood numbers with up to 60-80 emergence holes/ 1800 cm2. Fire-defoliated trees provided bark beetles with sufficient phloem and limited resistance, allowing beetles to aggregate on areas of viable stem tissue regardless of overall bole char extent.

Hurricane Katrina damaged 1.4 million hectares of forestland in Mississippi. Hardwood timber accounted for 40 percent of the damage. A cost-effective method of artificial regeneration is necessary to restore this resource. Bareroot, containerized, and EKOgrown® seedlings of Quercus shumardii and Quercus nuttallii were planted on two sites for evaluation of survival and growth. Survival was recorded monthly during the first growing season, and at the end of each growing season. Growth was measured at the end of each growing season. Survival was extremely low in 2014. Containerized seedlings suffered a total loss due to freezing at the nursery, and a large flood occurred on one site. After the two growing seasons monitored in this study, bareroot seedlings provided similar or greater growth, greater survival, and were remarkably cheaper than EKOgrown® seedlings. Consequently, bareroot seedlings are recommended as the most cost-effective method of artificial oak reforestation.

The genus Castor is represented in Eurasia by Castor fiber, North America by C. canadensis, and has been in North America since the late Miocene. This study aims to assess whether morphology of Miocene-Pliocene C. californicus and extant C. canadensis are distinctly different. Specimens of Castor were compared using geometric morphometrics on cranial material and linear measurements of postcranial material. Species occurrence data were compared with past and future climate data to assess Castor distribution in North America through time. Results show that C. canadensis is highly variable in both cranial and postcranial morphology and C. californicus falls largely within the range of variation seen within the extant species. Past distributions match fossil occurrences of Castor, suggesting confidence in projected models. Morphological and distribution similarities between the two species suggest that they can be treated as ecological analogs, though evaluation of whether they are conspecific will require more data.

ABSTRACT SALT DRIVE IN THE BEAVER (Castor canadensis): AN EXPERIMENTAL ASSESSMENT WITH FIELD FEEDING TRIALS SEPTEMBER 2012 JENNIFER E. STRULES, B.M. BERKLEE COLLEGE OF MUSIC M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Stephen DeStefano Salt drive is a seasonal phenomenon common to several classes of wild herbivores. Coincident with shifts of nutrient quality when plants resume growth in the spring, sodium is secondarily lost as surplus potassium is excreted. The beaver (Castor canadensis) is an herbivore whose dietary niche closely follows that of other herbivores that are subject to salt drive, but no published studies to date have assessed the likelihood of its occurrence. To quantify if beavers experience seasonal salt drive, we designed a field experiment to measure the foraging responses of beavers to sodium-enhanced foods. We used sodium-treated (salted) and control food items (aspen [Populus tremuloides] and pine [Pinus spp.] sticks) during monthly feeding trials at beaver-occupied wetlands where water lily (Nymphaea spp. and Nuphar spp.) was present and where water lily was absent. If conventional ontogeny of salt drive was operant, we expected to observe greater utility of sodium-treated food items by beavers in May and June. Further, if water lilies supplied beavers with sodium to meet dietary requirements as is widely speculated, we expected foraging responses to sodium-treated food items at wetlands where water lilies were absent to be greater than at wetlands where water lily was present. Aspen was selected by beavers in significantly greater amounts than pine. There was no difference between the mean percent consumed of salted and control aspen sticks by beavers at lily and non-lily wetlands, and no differences in temporal consumption associated with salted or control pine sticks at either wetland type. Salted pine was consumed in greater amounts than unsalted pine. We propose that the gastrointestinal or renal physiology of beavers may predispose them to low solute loss, thereby preventing salt drive.

Den gropkeramiska kulturen är förknippad med kustlandskap och ett osteologiskt material bestående av fisk och säl, men kulturen fanns också vid inlandets insjöar där fisk och bävern istället är framträdande i det osteologiska materialet. Vindförbergs udde är en av flera gropkeramiska inlandslokaler belägen i Dalarna, det som utmärker Vindförberg från andra omkringliggande lokaler är lokalens höga och branta placering i landskapet. Syftet med uppsatsen är att tolka vad för slags lokal Vindförbergs udde varit, varför bävern är framträdande i gropkeramiska inlandslokaler, och hur inlandslokaler skiljer sig från eller liknar kustlokaler. För att svara på frågorna har en osteologisk analys av stenåldersmaterial från Vindförberg gjorts, och en komparativ metod har tillämpats där det osteologiska materialet jämförs med två kustlokaler i Hälsingland, Gästrikland och en inlandslokal i Dalarna. Diskussionen har fokuserat på Vindförberg som lokal och bävern som ett betydande djur, utifrån de frågeställningarna har likheter och skillnader mellan samtida inlands- och kustlokaler presenterats. Resultatet tyder på att Vindförbergs udde kan ha nyttjats året om, där både slakt, konsumtion och verktygstillverkning försiggått. Bävern är framträdande i materialet från Vindförberg och andra inlandslokaler, i samband med bäverns och sälens vattenlevande levnadssätt kan en tolkning av att bävern varit substitut för sälen göras. Likheter mellan gropkeramiska inlands- och kustlokaler kan ses i lokalernas placering i landskapet och kontakter med andra grupper. En tydlig skillnad är det osteologiska materialet där faunan skiljer sig åt. / The pitted ware culture is associated with coastal landscapes and an osteological material consisting of fish and seals. However, the culture also lived alongside inland lakes where fish and beavers were prominent instead. Vindförbergs beak (Vindförbergs udde) is one of several pitted ware culture sites in the inland located in Dalecarlia. What distinguishes Vindförberg from other surrounding premises is the beak’s high and steep location in the landscape. The purpose of this study is to interpret what kind of locale Vindförbergs beak was, why the beaver is prominent in inland pitted ware culture sites, and how inland sites differ from or resemble coastal sites. To answer these questions, an osteological analysis of stone age material from Vindförberg has been carried out, and a comparative method has been applied where the osteological material is compared with two coastal sites in Hälsingland, Gästrikland and one inland site in Dalecarlia. The discussion is focused on Vindförberg as a site and the beaver as a significant animal, and based on the paper’s research questions presents similarities and differences between inland and coastal sites. The results indicate that Vindförberg’s beak may have been used all year round, where both butchering and toolmaking were taking place. The beaver is prominent in the material from Vindförberg and other inland locations. Based on the aquatic lifestyle of the beaver and the seal, an interpretation can be made that the beaver was a substitute for the seal. Similarities between the inland pitted ware culture sites and the coastal sites can be seen in the location of the sites in the landscape and contacts with other groups. A clear difference is the osteological material where the fauna differs.