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139 Uppsatser om Boreal streams - Sida 3 av 10

Effekten av kvävegödsling på gasproduktionen vintertid i boreala sjöar

To investigate effects of nitrogen on in-lake CO2 and CH4 production during winter, three pair of lakes was subject for a fertilizing experiment in which one lake in each pair was fertilized with nitric acid (HNO3) directly into the water column in the summer of 2012. The lakes in each pair are assumed to be morphologically, hydrologically and biologically similar, that is, the non-fertilized lakes are considered references. The pairs do differ in one major way by being progressively less humic, going from around 25 mg/l to 10 mg/l DOC. Sampling and analysis was carried out at the end of the frozen period in 2013. Results show a significantly higher concentration of both CO2 (p<0,001) and CH4 (?=0,1, p=0,053) between impact and reference sites in the two less humic pairs.

"Land skall med lag byggas" - en studie av policyprocessen kring ett lagförslag -

This thesis concerns the policy process of a proposed bill. The specific bill constitute a new penal law which is supposed to replace the old penal law from 1974.The questions asked considers what in the foregoing policy process that has proceeded, affected and also characterizes the proposed bill. In order to be able to produce a deep and reliable analysis to this question I use two different theories.The first theory being used consists of John W. Kingdons theory of ?multiple streams? which I use to answer the specific question ?what can be recognized to have proceeded and characterize the policy process that the penal law bill involve??.The second theory consists of Peter Santesson-Wilsons development of symbolic policy theories which is given a concrete form in the ?taxonomy of symbolic policy? which he presents.

En utvärdering av temperaturproblem samt närsaltsbelastning i odlingsdammarna och Flugströmmen i Harasjömåla

This bachelor?s project deals with both the problems of high water temperatures in fishponds at a fish-breeding station and of the nutrient load to nearby lakes and streams in Harasjömåla, Blekinge, Sweden. Theory, methods and results of the analyses are presented in the report..

Flottledsåterställning i norra Sverige: : effekter på habitatkvalitet och populationstätheter av juvenil öringar (Salmo trutta L.)

In an effort to evaluate the effects of restorations of float ways on population density of stream dwelling fish in relation to the changes in habitat, I studied the physical habitat restored and channalized sites and their population density of brown trout (Salmo trutta L.) in three streams in the municipality of Sorsele. The differences between the channalized and the restored sites where most noticeable regarding substrate which where generally coarser in the restored sites. The analyses showed that the proportion of habitat that where suitable to the age class 0+ where significantly lower in the restored sites compared to the channalized sites. Regarding age class ?2+, no statistical differences in habitat quality were found.

Magasin för lagring av vatten och växtnäring

Structural rationalizations and regionalization of the agricultural sector in Sweden has lead to unevenness in thedistribution of plant nutrients. Nutrients are lost from crop producing farms as harvest products are sold, whilefarms with animal production often have manure in excess of their needs. In addition to this the retention ofwater and nutrients in naturally occurring wetlands has decreased due to a reduction of wetlands in number andsize in the agricultural landscape. This increases nutrient levels in agricultural run-off and causes eutrophicationas well as nutrient losses from arable soils. One potential solution to both problems would be to store nutrientrichsurface water from agricultural areas and use it for irrigation of agricultural crops.

Exosomes as a potential mechanism of intercellular spread of prion protein

Structural rationalizations and regionalization of the agricultural sector in Sweden has lead to unevenness in thedistribution of plant nutrients. Nutrients are lost from crop producing farms as harvest products are sold, whilefarms with animal production often have manure in excess of their needs. In addition to this the retention ofwater and nutrients in naturally occurring wetlands has decreased due to a reduction of wetlands in number andsize in the agricultural landscape. This increases nutrient levels in agricultural run-off and causes eutrophicationas well as nutrient losses from arable soils. One potential solution to both problems would be to store nutrientrichsurface water from agricultural areas and use it for irrigation of agricultural crops.

Ackumulation av CO2 och CH4 i istäckta boreala sjöar : Hur förändras ackumulationen i sjöar påverkade av avverkning jämfört med referenssjöar?

The aim of this report was to quantify the accumulation of carbon dioxide (CO2) and methane (CH4) in ice-covered lakes in winter (October-March) during three consecutive years, and to assess whether the concentrations of DIC and CH4, as well as the ratio DIC:CH4 differs between years and between lakes affected by clearcutting and untreated reference lakes. Water- and gas samples were collected from four boreal lakes (two affected by clearcutting and two untreated reference lakes) located in Västerbottens inland in spring. The lakes were found to accumulate on average 91, 55, and 84 mgCm-2d-1 during winters 2012-2013, 2013-2014, and 2014-2015, mostly originating from CO2. The concentrations of DIC (autumn and spring) were higher in the affected clear-cut lakes compared to reference lakes for all years, including the reference year (2012-2013) before clear-cutting. No such difference was found for CH4 or the ratio DIC:CH4.

Utvärdering av den nationella databasen över åtgärder i vatten i fem svenska huvudavrinningsområden

Restoration projects are planned and carried out in order to reduce the impact due to anthropogenic influence and to achieve at least good ecological status according to the EU Water Framework Directive. The resilience effort of such restorations is however ambiguous. The aim of this study was to evaluate the potential of follow up restoration measures in Swedish lakes and streams. In particular, we visualized the geographical spread of restoration measures in Sweden and quantified the different types of measures that were implemented so far. Further, we evaluated the extent of sampling of biological factors before and after the restoration measures have occurred. For the purpose of our study, we used the recently compiled national database of restoration measures in Swedish lakes and streams.

Brandrelaterade insekters lokala artrikedom i förhållande till olika miljövariabler : Fokus på betydelsen av konnektivitet på brandfält i boreal skog i Västerbottens län

The last century, forest fires have decreased in frequency due to efficient fire-suppression along with the growth of the industrial forestry. Since 1990, fire has been reintroduced under controlled forms to recreate burnt habitats. Many species that are dependent on, or benefits from, forest fires have increased since fire was reintroduced. The importance of connectivity is often addressed in ecological research. This is particularly important for species dependent on short-lived habitats such as burnt forests.

Insect communities inhabiting Inonotus radiatus growing on Alnus glutinosa trees at northern and southern shores of boreal lakes

This is a study of the insect community associated to the wood-decaying fungus Inonotus radiatus found on Alnus glutinosa trees growing in riparian forests at the northern and southern shores of boreal lakes in the province Uppland. Little is known about this particular bracket fungus and its inhabitants. Insects were reared out at the laboratory from samples of fruiting bodies of the fungus taken at five lakes. During the fieldwork in 2009, data about several environmental variables was also taken. After the rearing period, these variables and their effects over the insects were analyzed.

Förslag till placering av anläggningar för att förbättra vattenkvalitén i Tidan

Considering water quality, landuse and reducion of wetland area in the watershed of Tidan, areas witch are in need of constructions to improve the water quality are identified. Constructions are suggested to be located within the smaller streams in the watershed, so that the water is treated before it reaches the stream Tidan..

Förslag till placering av anläggningar för att förbättra vattenkvalitén i Tidan

Considering water quality, landuse and reducion of wetland area in the watershed of Tidan, areas witch are in need of constructions to improve the water quality are identified. Constructions are suggested to be located within the smaller streams in the watershed, so that the water is treated before it reaches the stream Tidan..

Habitat use and ranging behaviour of GPS tracked juvenile golden eagles (Aquila chrysaetos)

Throughout its wide distribution in the northern hemisphere, the golden eagle occurs in a diverse range of environments, e.g., mountainous, forest and open areas. The literature on juvenile golden eagles is limited, and this study provides further knowledge on habitat use and ranging behaviour during the post-fledging period in boreal Sweden. A total of 14 golden eagle juveniles were tagged with GPS transmitters during 2010 and 2011, and nine could be followed during the entire post-fledging period from fledging until migration. The juveniles fledged at the end of July and beginning of August and initiated migration during October and beginning of November. The length of the post-fledging period, until migration started, ranged from 49 to 97 days. During this period, the juveniles? distance from their natal nest and their GPS height increased with time as their flying abilities developed.

En vision om Enhetsskolans återkomst

I have taught pupils in several schools in eighth and ninth grade in ?weak? groups in mathematics. Most of them seemed to possess potential, but lacked motivation. Even though I tried several pedagogical methods, these approaches failed to engage the students. This prompted thoughts that this may reflect a broader structural problem about the organisation of education in Sweden.

Frigörelse av kvicksilver och metylkvicksilver till bäckvatten under olika perioder efter skogsavverkning :

High levels of Hg in fish in Swedish lakes have been a problem along time in Sweden. The major concern is production and accumulation of the most toxic form of mercury; methyl mercury (MeHg). Consequently, in about half of our 83 000 lakes fish contain concentrations above the recommended limit for human consumption of 0,5 mg mercury per kg fresh weight (most of it in the form of MeHg). Consumption of fish containing too high levels of MeHg may cause problems for both humans and animals. Three major sources of MeHg in surface waters are: 1) runoff from terrestrial areas, 2) deposition from the atmosphere, and 3) internal production of MeHg in lakes and streams. The aim of this study was to investigate the effect of clear-cutting on the concentration of Hg and MeHg into draining streams.

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