Freshwater ecosystems have long been neglected as an important part of the global carbon cycle. However, research shows that most of the world?s lakes are net-heterotrophic and consequently emitters of greenhouse gases to the atmosphere. In many boreal and north-temperate lakes, most of the yearly emissions usually occur in spring, shortly after Ice-thaw. The aim of this study was to quantify the flux of carbon dioxide (CO2) and methane (CH4) in three boreal lakes, during this annual event.

Previous studies of central tire inflation (CTI) in truck transport of roundwood have shown potential benefits to include more even wood flow and reduced road damage. The greatest benefits are found to be during periods of low bearing capacity such as spring thaw. No previous studies have examined geographical variations in the potential benefit of CTI-equipped trucks. The aim of the study was to develop and use a simple method for geographically prioritizing the use of CTI-equipped trucks within a forest company´s sector of activity.The host company for the study was Holmen Skog. The area studied consisted of Holmen Skog?s entire sector of activity extending from the province of Västerbotten to the province of Småland.

The problems around and the planning of wood flow is some of the most complex issues in the forest-sector. The experience and overview of the single employees is crucial for the possibility of correct tactical and economical decision-making. The increasing demand of savings and shorter reaction-times with greater flexibility in the wood-supply-chain, makes solutions and aids for improved effectiveness in the work and processes according to wood-flow urgent. Holmen Skog is starting to develop a new forest-road-management-system. The system will facilitate the work according to construction, improvements and updating the standard of roads.

The low bearing capacity of roads during the spring thaw and periods in the autumn leads every year to increases costs for Holmen Skog. To reduce costs and increase accessibility Holmen Skog decided to install and test a CTI-system. Central tire inflation (CTI) is a system that makes it possible to monitor and vary a vehicle?s tire inflation pressures from the cabin, while the vehicle is in motion. When tire pressures are reduced, the area of the contact surface between the tire and the road increases, thus reducing the ground pressure. The purpose of this study was to evaluate the CTI-equipped vehicle and analyze if the CTI technology is economical defensible during the thaw 2005.

The objective of this thesis was to develop a method for the planning of road upgrading at Holmen Skog, a Swedish forest company. A critical issue for creating such plans is to identify roads that are suitable to upgrade to a standard that can handle heavy traffic during spring thaw, since spring thaw is a bottle neck for transporting timber. The method was tested in a case study at a district. The work consisted of two parts. The first was to retrieve and prepare geographical data for the roads.

Crypreservation of oocytes is recently being considered to be a valid choice in infertility treatments.Low survival and fertilization rates due to inefficient slow freeze protocols have been the outcome ofmany previous studies done in the field. However, introduction of the vitrification technique and itsapplication in reproductive medicine and to some extent new improved slow freeze protocols haveshown that oocytes can be cryopreserved with successful outcome.In this project the survival rate of oocytes after vitrification with MediCult Vitrification andWarming Media has been studied. Also, a comparison of the carriers Cryoloop (an open system) andCryopette (a closed system) has been performed.A total of 43 oocytes were vitrified and warmed according to MediCult's protocol, of which 21oocytes with Cryoloop and 22 with Cryopette. The cells were post-thaw incubated in a physiologicalenvironment for 24h. During that time the morphology and viability were observed and noted after 2h,over night and after 24h.

Phosphorus is the single most potent contributor to eutrophication of freshwater and has also been shown to contribute to the toxic algae blooms in the Baltic sea. The dynamics and paths of losses of phosphorus from arable lands are not fully understood. It is known that phosphorus can be lost directly from plant material to water. In studies where plant material has been subjected to several freeze-thaw cycles, large amounts of phosphorus have been lost. Most studies have been conducted under field conditions, with many factors effecting the measured losses of phosphorus, such as weather and type of soil. This study was performed in a controlled environment without the presence of soil. Instead of soil, small glass beads were mixed with the plant materials in vessels, to make possible homogeneous leaching with water through the mixture of glass beads and plant materials. In this study, clover, ryegrass and dry straw were cut to pieces, approximately 2 cm long.

The purpose of this thesis was to create a strategic/tactical road access plan. This was done by designing an analytical method which gives the road manager a template to create long-term road access plans. The analytical method will help to identify and appraise roads to be upgraded and give information when it is time for building new roads. The study method involved developing an analytical method. The method was comprised of five main parts: the harvest plan, analysis of the road network, transport costs, quality and storage costs and finally, identification of investment alternatives.