Stormwater in urban areas has been treated as a problem for a long time. The large proportion of impermeable surfaces inhibits the water from infiltrating in the ground to the same extent that it does in nature. This causes intensive surface flow during rain, which in turn causes inconveniences such as decreased accessability, floods and increased risk of desease spreading. Drainage through pipes is the traditional and usually functional metod for storm water disposal. That is as long as water flows are moderate. But precipitation varies naturally in amount and intensity and additional impermeable surfaces make some pipes insufficient for heavy or lasting precipitation.

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 TÃ¥kern, 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.

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

This essay is a study and analysis of the funnel beaker pottery at Gullarve 1:13 in Väte parish. The purpose of the study is to analyse the chronology of the settlement by determine the distribution, stratigraphic context and the ornamentation of the pottery. Another purpose is to discuss the geographical location of the settlement in the landscape.In this essay a short review of the pottery and the funnel beaker culture as well as a description of the pottery from the archaeological excavation from 1984 at Gullarve 1:13 is presented. Since the documentation of the archaeological excavation from 1984 is missing or is very inadequate, no spatial analysis can be carried out. The distribution of the pottery can?t contribute to the result of the essay, though if possible it probably would have provided some interesting results.

The thick-shelled river mussel (Unio crassus) is a red listed species classified as Endangered (EN) and is also considered within the Habitats Directive. The distribution in Sweden is fragmented and it is mostly occurring in the south eastern parts. We investigated the presence of Unio crassus in a section of the stream Storån, Östergötland County, from Falerum to the inflow into Lake Åkervristen. The environmental parameters investigated were water depth, bottom substrate, shading, water velocity and the slope over the water surface. In this thesis I have focused mainly on water depth and shading, comparing sites with and without mussels.

The Savi?s Warbler (Locustella luscinioides) is a recently established bird species in a few reedy shallow lakes of southern Sweden and has only been found nesting for the last twenty years. Little is known about the species' habitat preferences, breeding biology and demands for specific territory structures at breeding sites in Sweden. Knowledge of a newly established species? habitat requirements is essential to maintain a viable population and design action plans.

The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant.A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland.

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.

Effects of climate change, urbanization and global homogenization are resulted in the degradation of land and losses of natural habitats. Ecological design integrates nature into urban environment by respecting natural ecological principles and processes and creating resilient urban biotopes which also can be used by local urban communities. The aim of the thesis is to answer the research questions: How ecological design principles can be applied for re-design of Toledo Riverfront (with requirements of the design competition)? and What is the ecological design in landscape architecture? I participated in the USA design competition with the aim to create a vision and redesign of Toledo Riverfront in Ohio State, USA. The site is located in the south point of Lake Erie. As a result of a long industrial activity, riverfront of Toledo had been transformed into inaccessible and abandoned brownfields. In my proposal I applied ecological design principles on three scales: the city of Toledo by reinforcing of ecological connection and creating green corridors along the river; the intermediate scale by suggesting public parks along the river front and on the fine level by proposing detailed design including remediation of the site and use of dredged material.

Three methods of sensitivity and unceartainty analysis have been applied to the operative stormwater- and recipient model StormTac. The study area is the watershed of lake Flaten in the municipality Salem. StormTac?s submodels for stormwater, pollutant transport and the recipient are cosidired. In the sensitivity assessment, the model parametres and inputs were varied one at a time by a constant percentage according to the ?one at a time? (OAAT) method and the response of the outputs were calculated.

Benthic diatoms are used in Sweden for monitoring water quality in run-ning water; the method is also frequently used in other countries in Europe. One of the problems of the diatom method is the need for sedimentation of the fresh sample, to be able to decant the over standing water and add alco-hol as a preservations solution. To my knowledge, no results have been published about how long the settling time must be to ensure that the ben-thic diatoms really have settled down to avoid a loss of the diatoms when decanting the over standing water. The aim of my investigation was to improve the Swedish method where the benthic diatoms are used for water quality monitoring. I wanted to find out the appropriate time necessary to wait until all diatoms have settled down before decanting the over standing water. First, fresh benthic diatom samples were taken in the river Fyrisån and the lake Mälaren on different days. After arriving in the laboratory, I waited three different times (30 min, 60 and 180 min) for the diatoms to settle.

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

For some time, there has been a general thought that churches built in the Early Middle Ages in Scandinavia, around the 12th century, directly replaced cult buildings or cult sites from the Late Iron Age. There are archaeologists who have criticized this and were instead skeptical that churches at all were built on places where a pre-Christian cult building existed. Several examples from Scandinavia contradict this and show a continuity of place and cult from the Late Iron Age to the Early Middle Ages. The aim of this thesis is through a spatial analysis, study Late Iron Age archaeological sites in the landscape around thirteen churches located around lake T?kern in the western part of ?sterg?tland, to see if there is a place and cult continuity from the Late Iron Age to the Early Middle Ages at the selected locations.

Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.

The location on the river delta of Klarälven, adjacent to lake Vänern, makes Karlstad one of the Swedish cities where a significant flood risk is present. The city has several major floods in its memory which has caused great material damage and economic losses, the latest of which occurred in the winter of year 2000/2001. The purpose of the study is to examine how the approach to flood risk has changed in the municipality of Karlstad since the 1950s, and how this change has affected the current situation regarding the city's vulnerability to flooding. To investigate this, a document analysis was conducted, where key documents in the media and from the municipality of Karlstad was studied. Furthermore, an interview study was conducted with respondents who currently are employed or previously have been employed in the municipality of Karlstad, who in various ways work with issues of flood risk. The result of the study shows that several changes have taken place since the 1950s in terms of the municipality's approach to flood risk, which for instance has led to preventative measures being taken to a greater extent than previously in the physical planning.