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Common species of freshwater mussels may, like the freshwater pearl mussel (Margaritifera margaritifera) have a drastic decline in number and there is several reasons, like sedimentation, a decline of host fishes, introduction of alien species, nutrition leakages from agriculture and pollutants of medic drugs and poison. Ann Gustavsson made in the year of 2007 a study over rejuventation of freshwater great mussels in nine watersystems and considered that the rejuventation within the populations were all along the line poor. This study orients from her work and points to determine if there is a connection between the poor juventation and pollution of nitrogen and phosphorous from industries and private sanitations. The study was performed with the software program ArcGIS9.2 to take out drainage areas for the concerned habitats and contact was made with the concerned authoritys. When it comes to supervision of private sanitations is it the countys and for industries is it the county administrative board. Most of the countys had a very difficult way to reach their data of the private sanitations and those who had data had great holes in their knowledge in them. The greatest emission of nitrogen was without doubt the industries, but a more even allocation could be seen in the pollution of phosphourus, where the industries and the private sanitations stood for about fifty- fifty of the pollution. The greatest emission of nitrogen and phosphourus happened in Viskan, in the drainage area for Lekvad,there it was a lack of mussels. The species of Anodonta anatina showed a strong positive correlation between emission of nitrogen and phosphourus with the way of juvenile mussels in the population. More studies is need to do in these areas, both when it comes to continuing mapping of rejuventation within the freshwater great mussels in several waters and template value for pollution of nitrogen and phosphourus, that is very doubtful today. Even studies concerning other factors, like predation, host fishes and the influence of poison and medic drugs is needing to do, as it is few studies concerning this today.

När storskaliga och kväveintensiva jordbruk bredde ut sig växte många betesmarker ochängar igen. Detta medförde att hävdberoende växtarter minskade eller helt försvann. Föratt kunna växa och återkolonisera marker behöver många arter olika störningar. En sådanstörning kan vara bränning. Vid bränning ökar ljusinsläppet och även kvävemängden imarken minskar, vilket gynnar de hävdberoende växterna.Detta arbete har undersökt om bränning kan vara ett komplement eller alternativ till beteoch slåtter vid bevarande av den biologiska mångfalden hos växter. I studien inventeradesbrända och orörda kontrollytor på 11 st olika gräsmarker i Östergötland. Dessagräsmarker inkluderar vägrenar, ängar, åkerslänter och naturbetesmarker.Tre olika diversitetsindex användes för att svara på om diversiteten var högre på brändamarkerna. Resultatet visade att diversiteten var högre och artfördelningen var jämnare påde brända ytorna än på kontrollytorna. De arter som är beroende av hävd hade en markantstörre utbredning på de brända markerna än på kontrollytorna. Detta bekräftar hypotesenom att bränning är positivt för hävdberoende växter och att bränning kan vara ettkomplement eller alternativ till bete och slåtter vid bevarande av den biologiskamångfalden av växter i gräsmarker. Den framtida skötseln skulle kunna vara olikakombinationer av bränningar, bete och slåtter.För naturvården kan detta konstaterande få betydelse genom att offentliga och privatamarkägare kan börja bränna fler områden med vetskapen att detta gynnar hävdberoendearter som är hotade. Att bränna marker istället för att slåttra eller beta kan leda till attstörre arealer kan få den skötsel de kräver utan förändringar i den finansiella budgetenhos markägaren. / When the large-scale and nitrogen-intensive agriculture gained land many naturalpastures and meadows started to overgrow. This led to that many species dependent onopen land decreased or totally disappeared. To grow or re-colonize land many speciesneed some form of disturbance. Burning can be one of such disturbances. Burningincrease the light inlet and decrease the amount of nitrogen in the soil. Both of thesechanges will favor the open-land species.The aim of this study was to explore if burning could be a complement or alternative tograzing and mowing for preserving the biological diversity among plants in grasslands.The different kinds of grasslands that were inventoried include hard shoulders, meadows,field slopes and natural pastures. Both burned and control areas were inventoried at 11places. All of them were located in different habitats in Östergötland, Sweden.Three different diversity-indexes have been used to answer the question if diversity washigher on the burned areas than on the control surface. The result showed that both thediversity was higher and the distribution in species spread more evenly on the burnedareas. Species dependent on open land had a notably larger spreading on the burned areasthan on the control areas. This confirms the hypothesis that burning has a positive effecton open-land species and can be a complement or replacement for grazing or mowing inpreserving the biological diversity of plants in grasslands. The future care could bedifferent combinations of burning, grazing and mowing.To the conservation, this knowledge can have a great impact for both state and privatelandowners. Knowing that this method will favor the open-land species, more areas canbe burned. To burn, instead of mowing or grazing, can lead to that larger areas can havethe proper maintenance it requires, without changes in the financial budget of thelandowner.

<p>När storskaliga och kväveintensiva jordbruk bredde ut sig växte många betesmarker ochängar igen. Detta medförde att hävdberoende växtarter minskade eller helt försvann. Föratt kunna växa och återkolonisera marker behöver många arter olika störningar. En sådanstörning kan vara bränning. Vid bränning ökar ljusinsläppet och även kvävemängden imarken minskar, vilket gynnar de hävdberoende växterna.Detta arbete har undersökt om bränning kan vara ett komplement eller alternativ till beteoch slåtter vid bevarande av den biologiska mångfalden hos växter. I studien inventeradesbrända och orörda kontrollytor på 11 st olika gräsmarker i Östergötland. Dessagräsmarker inkluderar vägrenar, ängar, åkerslänter och naturbetesmarker.Tre olika diversitetsindex användes för att svara på om diversiteten var högre på brändamarkerna. Resultatet visade att diversiteten var högre och artfördelningen var jämnare påde brända ytorna än på kontrollytorna. De arter som är beroende av hävd hade en markantstörre utbredning på de brända markerna än på kontrollytorna. Detta bekräftar hypotesenom att bränning är positivt för hävdberoende växter och att bränning kan vara ettkomplement eller alternativ till bete och slåtter vid bevarande av den biologiskamångfalden av växter i gräsmarker. Den framtida skötseln skulle kunna vara olikakombinationer av bränningar, bete och slåtter.För naturvården kan detta konstaterande få betydelse genom att offentliga och privatamarkägare kan börja bränna fler områden med vetskapen att detta gynnar hävdberoendearter som är hotade. Att bränna marker istället för att slåttra eller beta kan leda till attstörre arealer kan få den skötsel de kräver utan förändringar i den finansiella budgetenhos markägaren.</p> / <p>When the large-scale and nitrogen-intensive agriculture gained land many naturalpastures and meadows started to overgrow. This led to that many species dependent onopen land decreased or totally disappeared. To grow or re-colonize land many speciesneed some form of disturbance. Burning can be one of such disturbances. Burningincrease the light inlet and decrease the amount of nitrogen in the soil. Both of thesechanges will favor the open-land species.The aim of this study was to explore if burning could be a complement or alternative tograzing and mowing for preserving the biological diversity among plants in grasslands.The different kinds of grasslands that were inventoried include hard shoulders, meadows,field slopes and natural pastures. Both burned and control areas were inventoried at 11places. All of them were located in different habitats in Östergötland, Sweden.Three different diversity-indexes have been used to answer the question if diversity washigher on the burned areas than on the control surface. The result showed that both thediversity was higher and the distribution in species spread more evenly on the burnedareas. Species dependent on open land had a notably larger spreading on the burned areasthan on the control areas. This confirms the hypothesis that burning has a positive effecton open-land species and can be a complement or replacement for grazing or mowing inpreserving the biological diversity of plants in grasslands. The future care could bedifferent combinations of burning, grazing and mowing.To the conservation, this knowledge can have a great impact for both state and privatelandowners. Knowing that this method will favor the open-land species, more areas canbe burned. To burn, instead of mowing or grazing, can lead to that larger areas can havethe proper maintenance it requires, without changes in the financial budget of thelandowner.</p>

Northern fringe populations generally have low amounts of genetic variation and inhabit habitats where specific adaptations are needed. On the Swedish west coast, the natterjack toad (Bufo calamita) inhabits skerry islands. I have examined: I) adaptation to two environmental stressors in this habitat; II) the genetic population structure within the skerry habitat; III) the effects of neutral genetic variation, selection and genetic drift on trait divergence within the skerry habitat; and IV) the effects of genetic variation on fitness under three thermal conditions of varying stressfulness. V) I have also studied the impact of putative local adaptations on the Scandinavian green toad (Bufo viridis) conservation programme. The results suggest that the skerry natterjack toads are locally adapted to the desiccation risk in their habitat. However, despite inhabiting a more saline habitat, they had a lower salinity tolerance when compared to their conspecifics in the more general habitat. The lowered salinity tolerance is most likely explained by the presence of negative genetic correlations between salinity tolerance and desiccation avoidance and suggests that the occurrence of multiple environmental stressors may constrain adaptation. Within the skerry habitat, the toads exhibited a strong population structure with populations differing in their levels of genetic variation. Moreover, within the skerry habitat, the results suggest uniform selection pressures. However, correlations between trait values and neutral genetic variation suggest that inbreeding depression may affect trait values and thus potentially constrain adaptation. In the natterjack toad, fitness costs associated with lack of genetic variation were only present under benign conditions and not under more natural conditions. This suggests that environmental stress masks inbreeding depression in these traits under natural conditions. In the study regarding the Scandinavian green toads, I found that one population inhabiting a saline habitat had a higher salinity tolerance than other populations in less saline habitats. This suggests the presence of local adaptation, which should be acknowledged in the green toad conservation programme. Several of the northern fringe populations of toads fulfill the criteria of being Evolutionary Significant Units and their conservation thus should be prioritized.