Pollution or changes in abiotic factors can be stressful if they exceed a species tolerance level, it can for example prevent the species ability to reproduce and disperse. High nutrition- and salt levels may be limiting for species in higher concentrations and affects all species since indirect, interactive and additive effects of high nutrient or salt levels lead to changes in the community structures. Algae blooms are a major problem in many lakes around the world and a reduced population of zooplankton had contributed to faster growth in phytoplankton and therefore eutrophication. The purpose of the study is to investigate species composition of zooplankton in a eutrophic- and oligotroph nutrient levels with different salt concentration and how it changes over time. Three salt concentrations (15, 250 and 1000 mg Cl-/L) along with the two nutritional levels resulted in six possible combinations replicated four times each, a total of 24 units. Zooplankton samples were taken from all units on day 19 and 78. A total of 51 different species were found throughout the study, of which a total of 34 species was found in the first sample and a total of 36 species in the second sample. The result showed an increase in Nauplii and Philodina spp. and a decrease in Daphnia pulex and Daphnia rosea. In the first sample a significant difference in the number of species was found between the salt concentrations 1000 mg Cl-/L and 15 mg Cl-/L and also between 1000 mg Cl-/L and 250 mg Cl-/L, where the total number of species decreased. There was also a significant difference in the species community between the nutrient levels from the first to the second sample, where a more even community was found between the first and second sample. The reduction in the number of species from the first to the second sampling may have been the reason why the species turned into communities that looked more like each other at the second test occasion, while the higher nutritional level may be what contributed to a community with higher evenness and similarity due to a greater opportunity to utilize food resources for the zooplankton without competition. The conclusion is that the salt concentration reduced the number of species, although the results show that salt concentrations with oligotrophic nutrient levels were more similar and had a greater similarity in amount of different species. Preserving lakes together with protective efforts is needed to reduce the ecological consequences of road salt, to be able to preserve species diversity and biodiversity in freshwater ecosystem.

Many species are today threatened by extinction. In streams and rivers, the historical clearing of obstacles in favour of transportation of floating timber has led to a decrease in the important habitat complexity. The larvae of freshwater pearl mussel (Margaitifera margaritifera) lives as a parasite on the gills of brown trout (Salmo trutta)wich effects the host negatively. In this study the effects of the activity, the amount of prey captured and the amount of initiated interaction with other trouts in different habitat complexity and different grade of infection from glochidia was investigated. The behaviour of brown trout was studies in the laboratory at Karlstads university in 2015. Analyses from data collected in laboratory studies at Karlstad University showed that there was no significant difference in activity or the amount of food captured between fish in complex and homogeneous habitats with high or low infection. In the case of initiated interactions there was a significantly higher rate of initiated interactions in homogeneous habitats than in complex habitats. The understanding of how the host is affected by parasites and even a changing habitat is important to be able to protect sensitive species with a parasitic lifecycle.

The moose population in Sweden is one of the highest in the world. The population have positive impacts on humans but also cause problems such as browsing damages and collisions with traffic. To manage this population in an adaptive and ecological sound way, the managers need to have as much information as possible. The aim of this study was to improve the description of Sweden’s moose management areas regarding available forage for moose. This is done by describing the heterogeneity of the landscape within the moose management areas, which is done by using different landscape indexes. The heterogeneity indexes is then used to analyze if correlation exists between the variation of the landscape and firstly data that describes the available food, secondly data that indicates the moose population density. Multiple regression analysis were done in order to find a model with the indexes that best explains the variation in available forage and moose population indicators.  The results in this study showed a positive correlation between number of moose shot per 1000 hectares and patch richness awhile a negative correlation was found between number of moose shot per 1000 hectares and edge density. Results also showed a negative correlation between both edge density and the patch richness in the landscape with the presence of rowan, sallow, aspen and oak (RASE). Further developments of indexes that describe landscape heterogeneity is needed, but this study may indicate that knowledge of the variation in the landscape might provide useful information on the prerequisites for the Swedish moose population.

Regulation and alteration of streams and rivers have a long history and dams provide us with resources. It also degrades the ecosystems connected to them by cutting off transportation routes and changing the flow regime. Riparian ecosystems have evolved to the natural flow regimes, making them sensitive to hydrological alterations. Riparian plant communities are often species rich and have a positive impact on their surroundings, but are often degraded because of flow alteration. Studies predict that riparian zones will lose species and extent because of climate change, making it increasingly important to manage and restore them.  This report examines the potential effects of two scenarios of a planned re-introduction of natural flow variation in the regulated river Juktån in Sweden. Riparian vegetation composition and cover was inventoried in plots with different amount of yearly flooding to assess current relationships between flooding and riparian vegetation. A rating curve was used to determine the relationship between discharge and river stage. GIS-modeling using LiDAR data and the rating curve made it possible to predict the extent of flooding with the two scenarios, and resulting potential changes in vegetation extent and composition. No significant correlation was found between species richness and number of days flooded under current flooding regime. Positive correlation was however found between elevation and species richness, bare soil and flooding, and vascular plant cover and flooding. The three most species-rich vegetation belts are expected to increase substantially in area with both scenarios, suggesting that positive response is likely with the introduction seasonal flow variation.

In biology, the winter season is less studied than other seasons partly due to technical and logistical difficulties. The Arctic region is undergoing rapid changes with shorter and warmer winters, shorter snow duration and considerable changes in snow and ice cover as a result. Climate change also has other consequences such as added influx of DOC to aquatic systems which may have repercussions for aquatic food webs. This study investigates the effect of ice melt on benthic oxygen production and also investigates the pelagic counterpart. This study also investigates levels of light, CO2 and DOC and their impact on benthic and pelagic oxygen production in a simulated climate change scenario. Sampling for the study took place at the Umeå University Experimental Ecosystem Facility which exhibits artificial ponds, some of which had been treated to simulate changes caused by climate change such as added DOC or having been artificially heated during summers. Measurements for O2, CO2 and light (photosynthetic active radiation) were collected from these artificial ponds at three different occasions around the time of ice release: Iced over conditions, after ice melt and later in spring. Ice melt was not proven to result in a difference in benthic oxygen production, as no significance could be found between O2-production during ice-covered conditions and later during the spring. Ice release did however seem to be the cause of a significant effect in the pelagic habitat which exhibited higher O2-production during the period of ice release. A significant difference in O2-production was also found in the pelagic habitat between ponds treated with added DOC and ponds that were not, but no such difference could be found for the benthic habitat. This highlights important differences between the habitats. The study proposes that earlier times of ice release, higher levels of DOC and higher summer temperatures may perhaps influence the oxygen production in the benthic habitat to a lesser extent than the pelagic habitat in northern aquatic systems, but this requires further studies.

<p>Abstract</p><p>The sediment requirements for freshwater pearl mussel (Margaritifera margaritifera) recruitment, in 18 rivers in the counties of Västra Götaland, Örebro, Värmland and Västmanland in Sweden, were investigated. The top 4 cm of sediment in the rivers was analysed in terms of size, distribution and organic compound within the fine sediment. The aims of the study were to determine whether there is a relation between sediment particle size compound and freshwater pearl mussel recruitment as well as between organic compound in fine sediment and recruitment of mussels. The study shows that there is a significant difference in the amount of organic silt between non-recruitment and recruitment sites with a higher percentage of organic silt in recruitment sites. There is also a legible difference between the amounts of silt per sample between non-recruitment sites and recruitment sites where there was significantly more silt in sediment samples of non-recruitment sites. With the exception of fine sediment, no significant difference was found between non-recruitment and recruitment sites regarding size class distribution.</p> / <p>Sammanfattning</p><p>Sedimentkraven för rekrytering hos flodpärlmussla (Margaritifera maragaritifera) i 18 svenska vattendrag belägna i Västra Götalands, Örebro, Värmlands och Västmanlands län undersöktes. Vattendragens översta 4 cm sediment analyserades gällande storlek, fördelning och organisk sammansättning i finsedimentet. Målen med studien var att fastställa huruvida det finns förhållanden mellan sedimentets partikelstorleksammansättning och rekrytering av flodpärlmussla samt mellan finsedimentets organiska sammansättning och rekrytering av musslor. Studien visar en signifikant skillnad i organiskt finsediment mellan icke-rekryteringsplatser och platser med rekrytering där rekryteringsplatser hade högre procentuell andel organiskt finsediment. En signifikant skillnad påvisades också mellan andel finsediment per sedimentprov där sedimentprov från icke-rekryteringsplatser innehöll en högre procentuell andel finsediment. Förutom gällande finsediment påvisades ingen signifikant skillnad i sedimentets storleksdistribution mellan rekryterings- och icke-rekryteringsplatser.</p>

No description available.

Abstract The sediment requirements for freshwater pearl mussel (Margaritifera margaritifera) recruitment, in 18 rivers in the counties of Västra Götaland, Örebro, Värmland and Västmanland in Sweden, were investigated. The top 4 cm of sediment in the rivers was analysed in terms of size, distribution and organic compound within the fine sediment. The aims of the study were to determine whether there is a relation between sediment particle size compound and freshwater pearl mussel recruitment as well as between organic compound in fine sediment and recruitment of mussels. The study shows that there is a significant difference in the amount of organic silt between non-recruitment and recruitment sites with a higher percentage of organic silt in recruitment sites. There is also a legible difference between the amounts of silt per sample between non-recruitment sites and recruitment sites where there was significantly more silt in sediment samples of non-recruitment sites. With the exception of fine sediment, no significant difference was found between non-recruitment and recruitment sites regarding size class distribution. / Sammanfattning Sedimentkraven för rekrytering hos flodpärlmussla (Margaritifera maragaritifera) i 18 svenska vattendrag belägna i Västra Götalands, Örebro, Värmlands och Västmanlands län undersöktes. Vattendragens översta 4 cm sediment analyserades gällande storlek, fördelning och organisk sammansättning i finsedimentet. Målen med studien var att fastställa huruvida det finns förhållanden mellan sedimentets partikelstorleksammansättning och rekrytering av flodpärlmussla samt mellan finsedimentets organiska sammansättning och rekrytering av musslor. Studien visar en signifikant skillnad i organiskt finsediment mellan icke-rekryteringsplatser och platser med rekrytering där rekryteringsplatser hade högre procentuell andel organiskt finsediment. En signifikant skillnad påvisades också mellan andel finsediment per sedimentprov där sedimentprov från icke-rekryteringsplatser innehöll en högre procentuell andel finsediment. Förutom gällande finsediment påvisades ingen signifikant skillnad i sedimentets storleksdistribution mellan rekryterings- och icke-rekryteringsplatser.

Fem gymnasieklasser på praktiska program i årskurs två och tre på gymnasiet fick svara på en enkät om fotosyntesen. Undersökningen genomfördes inom kursen Naturkunskap A. Antal elever som deltog i undersökningen var 78 st. Jag genomförde även en lektion kring fotosyntesen i två av klasserna. Dessa två klasser deltog även i en efterstudie. Frågeställningar för studien var: Vad kan elever om fotosyntesen inför kursen Naturkunskap A på gymnasiet? Vad har eleverna lärt sig efter avslutat arbetsområde där fotosyntesen ingår? Skiljer sig de praktiska gymnasieelevernas förkunskaper på den undersökta skolan kring fotosyntesen från teknikprogrammets elever på samma skola? Enkätresultatet visar att eleverna har svårt för begreppet fotosyntes och kan inte identifiera var i växten fotosyntesen sker. Dock är det många som anger att fotosyntes sker i björklöv. I övrigt anger i stort sett lika många de felaktiga alternativen som de rätta. Eleverna förstår inte att luften är inblandad i viktökningen hos en växt. Eleverna visar progression vad gäller identifikation över var fotosyntesen sker och i nästan alla övriga av enkätens frågor.  Denna progression saknas vad gäller vilka ämnen som bygger upp en växt. Eleverna kan inte identifiera koldioxidens roll för viktökningen. Vid en jämförelse med teknikprogrammets elever, Åberg (2002), visar eleverna på de praktiska programmen svagare resultat. Dock följer resultaten samma mönster vad gäller svarsalternativen.

Syftet med denna undersökning är att ta reda på vilka kunskaper inom ekologi högstadieelever har med sig till gymnasiet. Eftersom de flesta gymnasieprogram innefattar kurser i naturkunskap eller biologi så vill jag ta reda på vad man som gymnasielärare kan förvänta sig att de nya eleverna har med sig i bagaget. Ekologi och hållbar utveckling genomsyrar stor del av samhällsdebatten idag och det är en del av skolan uppdrag att ge eleverna möjligheter till att ta ansvar för miljön som de kan påverka. För att en gymnasielärare ska kunna fortsätta utveckla sina elever är det av stor vikt att veta vilka grundkunskaper eleverna bär med sig. Detta för att läraren ska kunna förbereda sin undervisning på bästa sätt för att eleverna ska kunna tillgodogöra sig denna. Jag har utfört en enkätundersökning med 100 elever i årskurs 9 i närförort till en större stad. Hälften av deltagarna avsåg att välja ett högskoleförberedande program och hälften ett yrkesförberedande program. En hypotes är att eleverna som väljer högskoleförberedande respektive yrkesförberedande program i gymnasiet kan ha olika grad av studiemotivation vilket skulle kunna visa sig i eventuella skillnader mellan de två undersökningsgrupperna i den kvalitativa kunskapen de bär med sig. Resultaten visade att det inte var någon större skillnad i kvalitativa kunskaper mellan de två undersökningsgrupperna, men det fanns en signifikant skillnad i svarssäkerheten mellan grupperna. Ett annat resultat av studien var att eleverna har med sig godkända kunskapskrav i ämnet biologi men saknar en förståelse för materiens kretslopp.