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.

Peat  lands  are  a  great  potential  resource  for  increased  forest  growth  in  Sweden, there  are  approximately  6.5  million  hectares  of  peat  lands,  whereof  around  70% produce less wood than one m3sk/ha and year and are therefore classed as forest waste  land.  There  are  over  200  000  hectares  of  peat  land  that  is  already  drained and  wooded,  and  that may  be  suitable  for  fertilization.  Forest  production  on  peat soils  usually  requires  drainage  and  fertilization.  Dewatering  requires  ditching  the area, so that the roots can have access to oxygen. Nitrogen is often abundant in the peat but other nutrients; especially potassium is in short supply. The  purpose  of  this  work  was  to examine  the effects  of  potassium  fertilization  on the  growth  of  spruces  that  were  planted  on  drained  peat  land  and  how  different amount of fertilizers affects the growth. Potassium deficiency is strongly growth inhibiting, since potassium is important for substance  transport  in  the  tree.  Potassium  is  also  important  for  the  carbohydrate formation, and because increasing the sugar content of the cells constitutes a lower freezing temperature does potassium availability in the soil play a major role in the winter  resistance  of  many  species.  Potassium  is  not  found  in  any  organic compounds in the tree, but is present in cell and tissue fluids. A fertilization trial was started in 1978 in Siljansfors Experimental Forest. The plots in the experiment were fertilized with different amounts of potassium and one plot was  left  without  fertilization.  All  plots  that  were  fertilized  with  potassium  grew considerably better than the unfertilized plot. The difference in production between the unfertilized plot and the plot that received the most potassium was 7.2 m3sk/ha and year. The unfertilized plot can still be classified as waste land. The theoretical production capacity was estimated using a Swedish system for site quality  estimation  of  wetlands  after  ditching  (dikningsbonitering).  The  plot  with most  potassium  produced  after  fertilizationaproximately  in  level  with  theoretical estimations.  Key  words:  Peat  land,  Fertilization,  Ditching,  Growth,  site  quality..

Water hardness indicates the concentration of calcium and magnesium ions in water. Water with high concentrations of these ions is described as hard water and water with low concentrations is described as soft water. Water that is too hard or too soft can lead to technical and economical problems. In collaboration with Midvatten AB, groundwater hardness in the Badelunda esker between Leksand and Avesta has been mapped, and an attempt has been made to explain the variations. For this purpose, different GIS programs, such as ArcView, ArcInfo, IDIRISI, and one geochemical modelling program, PHREEQC, has been used.

In 1886 Hans Hildebrand received a Bronze Age hoard found in a field that belonged to Eskelhem´s rectory. A record was made where Hildebrand presented and documented the artifacts. The following year Oscar Montelius reviewed the artifacts, which he described as horse gears. He compared the horse gears with similar artifacts found in Europe that roughly had the same dating in order to trace the origin of the hoard.  Montelius conclusion was that the hoard was created on Gotland around 500 BC.

Open ecosystems, such as grasslands and pastures, have naturally been shaped by disturbances like fire and grazing. These processes play a crucial role in creating habitats with high biological diversity, particularly favourable for a wide range of herbaceous plant species. In recent years, many of these disturbances have ceased, leading to encroachment, fragmentation and habitat loss. The aim of this study was to examine and compare the effects of fire, herbivory and a combination of fire and herbivory on the emergence of herbaceous plants. The study was conducted at the Ecopark at Nordens Ark.

Lotsbroverket is the largest wastewater treatment plant on the Aland Islands and it isdesigned for handling wastewater from approximately 30 000 persons. In 2011,Lotsbroverket produced about 2800 m3 of dewatered sludge. The sewage sludge that isproduced is transported to a contractor where it is processed to eventually be used e.g.in the construction of green space. This study aims to investigate available applicationoptions in terms of the sewage sludge that is produced in Lotsbroverket. The main aimis to study the feasibility of using the produced sewage sludge as a fertilizer in theagriculture of the Aland Islands.The sludge already fulfills limit values for heavy metals in accordance with the Act"The Aland Government´s directive on the use of sewage sludge in agriculture." Inorder to clarify the sludge content of pharmaceutical and organic substances it isrequired that the substances are identified and a risk assessment is performed.

Carbon dioxide in the atmosphere contributes to the greenhouse effect, which is essential tolife on our planet. Furthermore, it plays an important part of the photosynthesis andrespiration of the world?s organisms. Since the start of the industrial revolution the amount ofcarbon dioxide in the atmosphere has increased exponentially. The main source is theextensive burning of fossil fuels.

Det råder i dagens läge konkurrens mellan gatuträden och infrastrukturen. Människan som lever i den urbaniserade världen vill ha alla bekvämligheter inne i staden som kräver avloppsledningar, vattenledningar, gatubelysning, elledningar m.m. Samtidigt vill man ha gröna ytor i staden med stora pampiga träd. Oftast får dessa två, träden och infrastrukturen, slåss om platsen under marken och det är oftast det gröna som får lämna plats. Eftersom detta är ett återkommande problem vid de flesta nybyggnationer och nyanläggningar av ledningar, gator, parkeringar etc.

At the end of April 1986 reactor number 4 of the nuclear power plant at Chernobyl explod-ed and large amounts of radioactive particles were then released into the atmosphere due to both the explosion as well as the consecutive fire of the graphite core. A cloud of radioac-tivity was spread over the northern hemisphere, including Sweden, due to the prevailing wind directions. The radioactive particles were washed out from the cloud by rain and snowfall in some areas of Sweden and deposited on the ground. The deposited radionu-clides, primarily cesium and iodine isotopes, were later absorbed into the soil and taken up by the roots of the plants. Some of these radionuclides, like 137Cs, still persist in some of the terrestrial ecosystems at relatively high concentrations which lead to contamination of the meat of moose, roe deer and wild boar even today.The two municipalities Heby and Uppsala, in the eastern part of central Sweden, experi-enced a relatively large deposition of 137Cs which resulted in high levels of 137Cs in moose and other game.

During 2006 SNVDB (the national road data base for forestry) is being introduced to Holmen Skog. This data base contains all information about Holmen Skogs road systems. The information will then be used in different kinds of optimisation models which only produce correct and reliable results if the input data are of the adequate quality. Today there are reasons to believe that road data is of various qualities. The forest roads are often in a bad condition and have to be improved before a planned harvest. The cost of maintenance and construction of new roads is a large part of the total harvesting cost.

The eutrophication of lakes and seas with the algal bloom and deficiency inoxygen that follow, has been given priority by the Swedish government as oneof 16 environmental objectives. The purpose of this project was to develop a toolbased on a simple model, limited amount of data and geographic informationsystem (GIS) to identify areas with risk for phosphorus losses due to surfacerunoff. This tool can act as a decision support to decide where appropriatemeasures should be applied with the aim of reducing phosphorus losses and bythat the eutrophication.The method that has been used is a combination of two models, one calculatingthe potential erosion while the other one identifies areas of erosion (net erosion)or deposition. This ability is of great importance because potential erosionshould be calculated on areas with net erosion. Areas with high potential erosionhave an increased risk for phosphorus losses due to surface runoff.The potential erosion was calculated based on factors which describe how topography(LS), land use (C), soil type (K) and precipitation (R) effect the erosion.All of them have been modified to a greater or lesser extent.

It has been observed by both onion producers and a plant protection advisor on Öland (an island off the east coast of Sweden) that basal rot is the largest contributory factor to reduced onion quality and yield. Basal rot is mainly caused by species of Fusarium fungi. The aim of this study was to: a) investigate which species of Fusarium that can be found in onion produced on Öland, b) describe the symptoms caused by the different Fusarium fungi found and c) explore, through interviews with the onion producers on Öland, the mechanisms that may be involved in the observed increase in basal rot.Onion bulbs (Allium cepa) were sampled on two occasions. In total 181 onions from 11 different fields were analysed. In addition, eight onion producers were interviewed.

When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.

X-ray fluorescence (XRF) detection of heavy metals is a cost- and time-effective method for investigation of polluted areas. Compared to laboratory analysis, XRF analysis is limited by high detection limits and uncertainties in some situations. Preparation of samples is known to affect the results of measurements.The purpose of this thesis is to bring a deeper understanding of how different factors affect the results of XRF-analysis. A large number of measurements have been made with the instruments Niton XLt 700 and Niton Xli 700. Results from measurements of lead, zinc and copper have been analysed.This study has shown that a greater moisture content will give a lower measured concentration for the same sample.

After the last is age there was a long period when there was no shortage of forest for peoples needs. People living in Sweden could use the forest resources at their will. Around 4000 years BC the inhabitants of southern Sweden started to use the agricultural system and people become more stationary. The farms were located together in groups and together they formed a social association, the village. Successively the population grew and in some areas the forest started to become a finite resource.