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<p>The purpose of the thesis work has been to develop methods and concepts to aid in the search, detection and assessment of ancient microfossils here on Earth as a guide to the search for ancient life on Mars. The intention has been to identify and characterize environments on Earth that may be considered analogous to Martian environments and in which fossil preservation is expected to be good, and to develop and apply methods to characterize the isotopic and chemical composition of possible traces of life in order to assess their biogenicity and biological affinities.</p><p>An investigation of the Siljan impact structure, Sweden, demonstrated that niches for thermophilic organisms were created in the associated hydrothermal system. The temperature regimes were favorable for thermophilic life in the outer parts of the structure during the early and main stages of the hydrothermal system, but that these niches moved toward the center of the crater during the final cooling stages. It was demonstrated that the hydrothermal system contains traces of a thermophilic microbial community, represented by fossilized extracellular polymeric substances (EPS). Given the presence of water on Mars, similar impact-induced hydrothermal systems were probably generated on Mars as well. These regions, like those at Siljan, may have supported hyperthermophilic microbial communities on the red planet, emphasizing the relevance of searching for impact-induced hydrothermal deposits for evidence of microbial life on Mars.</p><p>A method for the determination of stable carbon isotopes with high lateral resolution of TEM (transmission electron microscopy) samples has been developed. The method is based on alpha-particle Rutherford backscattering (RBS), it is non-destructive, and therefore suitable for analysis of extraterrestrial and other rare or irreplaceable material. Also, a novel concept to extract fluid inclusions without ablating the sample has been proposed, and a proof-of-concept has been demonstrated. The purpose is to analyze organic biomarkers trapped in fluid inclusions without risking contamination, and also to extract and analyze single fluid inclusions. The minimized contamination risk and the potential to extract single fluid inclusions could make the method a useful tool in the search for organic biomarkers in early-Earth material, and eventually, in samples returned from Mars.</p>

<p>Sediments in two aquatic environments have been investigated. Both are anthropogenically affected and polluted. The focus has been on stable carbon and nitrogen isotopes, C/N ratios, and heavy metals. </p><p>The first site is Höggarnsfjärden Bay in the inner parts of the Stockholm Archipelago, Sweden, where a garbage dump releases treated leach water. The effect on carbon and nitrogen in the sediment close to the discharge is large, but 1200 m downstream the effect is diluted by the background discharge of the town of Stockholm and the Lake Mälaren, which drains into the archipelago. The main source of the studied metals is not the garbage dump itself. The sediment close to the discharge shows high enrichment factors due to high sedimentation rate and adsorption, and low decomposition of organic matter. The metal enrichment factors of downstream sites are not higher than the upstream sites. </p><p>The second site is Lake Verkasjön close to the north part of Lake Vättern, in the county of Örebro, Sweden. River Salaån flows through Lake Verkasjön on the way through a former mining area to Lake Vättern. Upstream of Lake Verkasjön an ore dressing plant site was used in 1877-1881 for extraction of zinc. During that period the sediment of Lake Verkasjön received high loadings of sulphidic tailings. Normal sedimentation after the event has lead to that the polluted sediment is found as a distinct layer at 18-22 cm. The layer is characterized by elevated metal concentrations, decreased organic matter content and increased stable carbon composition. The sediment that has accumulated above 18 cm works as a physicochemical barrier that seals the waste from the overlying sediment. At the time of the event the signal of aquatic production in the sediment changed; the sediment above the layer has an increased proportion of aquatically produced material, implying changed land use in the catchment area.</p>

<p>This thesis is a study of Holocene sapropels from two semi-enclosed seas; the Baltic Sea and the Mediterranean Sea. Sapropels are sedimentary layers with organic C > 2%. The Baltic Sea and the Mediterranean Sea have a limited water exchange, and despite differences in water depth and salinity, mechanisms for fluxes and preservation of C_org are principally the same. Primary focus is on biomarkers for increased primary productivity and anoxic/euxinic bottom water. Pigments (primarily from cyanobacteria), δ¹⁵N, δ¹³C, N and C_org have been used for studying increased primary productivity. Presence of the pigment isorenieratene from green sulphur bacteria indicates photic zone anoxia. Zn, Mn and δ³⁴S have also been used to identify different scenarios during sapropel formation.</p><p>Pigments start to appear at the beginning of both the Baltic Sea sapropel and S1, the Holocene sapropel in the Mediterranean Sea. Cyanobacterial pigments generally increase early in the sapropel, due to fast adaptation to more P-rich conditions. Cyanobacteria are favored by low N/P-ratios and P was probably in excess during the formation of S1 and the Baltic Sea sapropel sediments. Lowering of δ¹⁵N and concurrent increase in N in both the Baltic Sea and S1 sapropels is probably caused by cyanobacterial N₂-fixation. This most likely increased the N/P-ratio and enhanced overall primary productivity. Both increased primary productivity and enhanced preservation of organic carbon are important mechanisms for sapropel formation. The appearance of isorenieratene in the protosapropel is most likely the result of an environment where even moderate increases in primary productivity could create anoxic conditions. This favours an estuarine water circulation scenario with anoxic bottom waters. δ³⁴S of sulphate and sulphide confirm this scenario, which can be explained by the coexistence of sulphate reducing and sulphur disproportionating bacteria together with phototrophic purple and green sulphur bacteria.</p>

<p>This rapport handles the presence of two kinds of watermills in the Swedish landscape. The first is a small type with a horizontal shovel blade and the other a bigger kind with a vertical standing shovel scoop. The rapport seeks for information of their capacity and how long they existed as flour producing units. A important issue is how small can a brook be and still run a mill. Finally the reasons for their disappearance in one selected parish is shown.</p>

<p>In the middle of the 19th century was Calluna heath the major nature type in Halland, but the remaining parts today is only 1 500 hectares which is a 99 % decrease of the Calluna heath mainly due to an increase in forest plantations and arable fields. I have made a quantitative study how the Calluna heath of Grönabur & Sandsjöbacka has changed between 1841 and 2005 and why it didn’t disappear in the same manner, as it did in other parts of Halland. </p><p>The studying of original sources as historical maps, literature and by doing field visits has been significant for the final result. The main reason for the different development of the Calluna heath in the investigation area (69 % decrease), compare to elsewhere in Halland, is the establishment and management of a nature reserve.</p>

<p>The essay on ”The revival of the countryside – a multitalent in landproduction.” focuses on local and regional development within agriculture, foodprocessing and tourism.</p><p>Due to great changes in society, the inhabitants in rural areas are forced to find alternative occupations. Using history as a tool to build up the future is a main factor in rural development. Apart from this it involves cooperation, resources, cultural heritage and values, entrepreneurship and innovation, economic vitality, and an understanding of markets and marketing. They all contribute to a region`s ability to benefit from rural development.</p>

<p>This study focus on the house ruins and land use in Nyokana, a former village section in Cata, by looking at their location, number and the people who lived there and their living before the Betterment plan was carried through. This is done by studying an old map and documents of Cata, field studies with GPS-using and by interviewing mostly old inhabitants. The result is a basis for the development of the planned tourism track within the heritage project, wich runs by BRC and University of Fort Hare.</p>

<p>Hällaryd archipelago, consisiting of approx. 50 islands, islets and skerries, is situated east of Karlshamn city in Blekinge province. The archipelago has been shaped into a rift valley by volcanic activity, the inland ice and maritime climate.</p><p>The archipelago is divided into seven main islands: Bockö, Västra Bokö, Ekö, Hallö, Joggesö, Mjöö and Tärnö. </p><p>This essay will connect population changes with land use. </p>