Feral animal Populations are distributed over many parts of the world and are often seen as a problem. Since they are a threat against other species, destroy farmlands and can spread dis-eases, they are often referred to as pests. Artificial selection has contributed to loss of genetic diversity in our domesticated animals. Feral animal Populations are affected by natural selec-tion, which allows them to adapt to the environment. Their ability to adapt is a reason to see them as pests but can also be seen as an asset.

Development of morphs within European whitefish (Coregonus lavaretus), might be considered as a beginning of a sympatric speciation process. Unpublished data suggests that presence of the keystone piscivore northern pike (Esox lucius) is the main driver of sympatric divergence in European whitefish (Coregonus lavaretus). Using introduced whitefish Populations as controlled experiments, it is possible to determine when different characters diverge in the speciation process. In this study, I analysed age and growth within European whitefish Populations of different age to assess if these characters change over time in absence of pike. With using otoliths from whitefish Populations of different age, I was possible to determine individual age, and by measuring the length of the fish, growth was calculated.

Over time, species colonize new areas naturally or through humans. The colonizers areoften few and founded Populations represent only a fraction of the genetic diversityexisting in the original population. If the established population becomes isolated afterthe colonization event genetic diversity will remain low and if the population, in addition,remains small in size for an extended period this will lead to increased inbreeding andpossibly inbreeding depression. Metrioptera roeselii is a common species with awidespread distribution in continental Europe. During the last century, it has expanded tothe Scandinavian Peninsula which is separated from continental Europe by the Baltic Sea.My aim was to test the hypothesis that individuals in isolated Populations in Scandinaviaincluding Denmark and the Baltic Sea islands are smaller than individuals in thecontinuous part of its distribution due to low genetic diversity and lacking incoming geneflow.

Pulsatilla vernalis is one of several endangered plant species that benefit from wildfires and small scale disturbance events that repel competing vegetation and create open patches in the vegetation cover. Previous studies argue that Pulsatilla vernalis is decreasing in numbers due to vegetation changes associated with the decrease in wildfires, forest grazing and changes in forest management. In this study, 17 Populations of P. vernalis were inventoried in order to examine if soil and/or vegetation structures affect the population structure of P. vernalis (i.e.

Hazel (Corylus avellana L.) is a common feature of meadows and pastures where it can grow in large Populations and become very old. Is it possible to use the size of hazel stools for age determination and is it possible to use the size distribution of a population to provide information about how the land has been used? Hazel Populations on ground where the lake-water level had been lowered, has been studied to validate an already developed growth model of hazel clones. Different hazel Populations, on wooded meadows affected by mowing or grazing or overgrown meadows, were studied to evaluate the method utilizing hazel as land use indicator. The growth model was used to compare the size distributions of hazel Populations with historical periods, which has been important for changes in agriculture or demography.

It is hard to find streaming waters where humans haven?t affected the fish Populations or the running water it self. In many streams the fish Populations are over harvested and this results in a lack of older and larger fish. This is also the situation for many Populations of Grayling (Thymallus spp.). To be able to develop management plans and to perform actions that improve the situation for the grayling, it is therefore crucial to know what natural, by humans unaffected Populations look like.

There are two species of potato cyst nematode (PCN), the yellow, Globodera rostochiensis, and the white, Globodera pallida. Each of them can appear in different pathotypes. These are separated by testing the nematode ability to multiply on a number of potato cultivars with different resistance properties. The aim of this project was to examine the virulence of Swedish and foreign PCN Populations and to compare two test methods. Biotests are today the only available tests used to study virulence.

The purpose of this report was to investigate to which extent local presence of large herbivore mammals (Alces alces, Cervus elaphus, Capreolus capreolus, Dama dama and Sus scrofa) covaries with small rodents (Myodes glaerolus, Apodemus flavicollis and Apodemus sylvaticus? The hypothesis was that high abundance of wild ungulates would inhibit the density of small forest rodents. The data was collected during field work within FoMA (Environmental Monitoring Assessment)/SLU (Swedish University of Agricultural Science). The Ungulate dropping inventory and rodent trappings, which is the base in this report, where performed 2012 ? 2014 in Gnesta/Nyköping municipalities (G/N) with a relatively high density of wild ungulates and Vetlanda/Växjö municipalities (V/V) with relatively lower wild ungulate density.

The great bustard (Otis tarda) became extinct in Sweden during the mid-19th century. Globally, Populations have suffered dramatic declines during the past two centuries. Recently, local Populations have stabilized or increased after hunting bans and conservation efforts. Despite positive trends the species is still classified by IUCN as vulnerable (VU), mainly due to withdrawals in the distribution. The limited distribution emphasizes the need for finding ?new? areas suitable for a translocation or reintroduction.

Osteological examinations were executed on nine mediaeval individuals from Västergarn, Gotland, with the main aim to increase the knowledge about the people who lived there during the Middle Ages. A further aim was to compare the results from this study with other Populations from the same time period, which in this case was the "Bonegathering" from Västergarn as well as previous osteological results from Sigtuna and Västerhus. Archaeological excavations have been occurring in Västergarn since 1971 and are still occurring in an educational purpose, for students of Gotland University. The age distribution of the individuals showed ages from 2 years old up to 44 years, with five adults and four children. The gender distribution show approximately five women and one man.

The large number of surrendered and feral cats is a big animal welfare problem all over the world. Populations of feral cats arise through a large number of unwanted cats which can lead to surrender of these, through cats allowed to roam free outside which can lead to the owner losing these and through the reproduction that occurs amongst these surrendered or lost cats. One aim of this study is to give an account of this problem. It is however difficult to draw general conclusions about these Populations of cats since studies all over the world has been carried out on different types of Populations, during different conditions and different periods of time. The welfare of many of these cats is presumably low because they are exposed to risks as disease, starvation, climate, traffic, other animals and humans.

Tomato production is a common and important agricultural activity in Nicaragua. During the last decades tomato producers have suffered great yield losses due to begomoviruses (family Geminiviridae). The genome of begomoviruses generally consists of two circular ssDNA components, DNA-A and DNA-B. Tomato yellow leaf curl virus (TYLCV) is an example of a begomovirus with only one component. An approach to manage the virus epidemics has been to breed a cultivar with begomovirus resistance genes, which have been transferred from wild tomato.

That ecological and evolutionary processes can take place on the same time scale is a recent insight. Today we also know that they are directly linked to each other. In the lake Tåkern, in year 2000, there was a structural change when phytoplankton declined and submerged vegetation, mainly stoneworts began to spread. This led to evolutionary changes in the aquatic sowbug, Asellus aquaticus which had previously been limited to the reed, most likely feeding on detritus. But then, sowbugs could exploit the new habitat in stoneworts and a new food resource in terms of periphyton.

The freshwater pearl mussel (Margaritifera margaritifera) is a large freshwater mussel. Because of its sensitivity to human impact, such as eutrophication, acidification and alterations of hydromorphology, the species is considered as a robust indicator of stream water quality and biodiversity. Moreover, due to the species complex life cycle, including a larval stage on the gills of salmon and trout, and sensitivity of early life stages, regeneration is often used as an indicator. The freshwater pearl mussel is also used in the expert judgement of status classification of benthic invertebrates according to the European Water Framework Directive. The purpose of this study was to gain a deeper understanding of the freshwater pearl mussel as an indicator for Swedish streams. It was made with two types of association analyses.

Many of Europe?s day-living butterflies have shown decreasing Populations during the last decades and many species are threatened. Many butterflies are dependent on managed semi-natural grasslands because of their richness in nectar sources and host plants for the butterfly larva. Swedish pastures are mostly managed through grazing. The number of cattle in Sweden have been decreasing while the number of sheep in the country increased by 30%.