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417 Uppsatser om Benthic composition - Sida 1 av 28

Två år efter restaurering:Vad har förändrats i bottenfaunan?

The aim of the study was to examine if the benthos in a restored portion of a small lowland stream south of Linkoping differed from two non restored reference areas two years after restoration. The reference areas were one stretch downstream and one upstream stretches of the restored stream. The benthic invertebrates were collected using standardized kick sampling. In order to classify the communities and estimate any differences, three different indices were exercised. In addition rank-abundance curves and checklists were used to get a picture of species composition.

Kan förändringar i bottenfaunan påvisas två år efter en bäckrestaurering?

The aim of this work is to analyze if a change in the benthic community can be detected two years after a restoration of a small stream. The samples were taken in a small stream at Tinnerö Eklandskap just south of Linköping. In addition to the restored area, two reference sites upstream and downstream of the restored area were sampled to compare to the restored site. The method used for sampling of benthic fauna in the stream was kick sampling. ASPT, Berger-Parker and Renkonen-indices were used to find out if there was any difference between the reference areas and the restored area.

Lillån : Statusbedömning enligt EU:s ramdirektiv för vatten

In Sweden, the County Administration board is responsible for improving the water quality in lakes and watercourses according to the European Union Water Framework Directive. In Västmanland county, where river Lillån is situated, the County Administration of Västmanland have the main responsibility for the aquatic environment in that area. The knowledge about the different watercourses in the chatchment of river Lillån is today limited. The aim with this study was to evaluate the ecological quality of River Lillån based on water chemistry analyses and benthic fauna investigations. The aim was also for the benthic fauna to compere different samplingsites and sampling methods with each other in order to see how the species composition changes in the river, and to see the advantages and disadvantages with different sampling tecniques.

Predation på evertebrater under tidig vår i sjön Tåkern

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

Hur påverkas bentiska funktionella födogrupper av kalavverkning? : Effekt på abundans, samt återhämning, av funktionella födogrupper efter kalavverkning kring små vattendrag.

Forestry affects most of the forest-covered land in Sweden. In the landscape, the most common stream type is headwaters, which are important sites for many processes and organisms in both the terrestrial and the aquatic ecosystems. The aim of this study was to investigate how the abundance of benthic invertebrate functional feeding groups in headwater streams develops after clear-cutting and if it also is possible to detect a change in the composition of feeding groups. The study also attempts to determine what factors have an effect on temporal changes in abundance of these groups. For the study, 11 sites in northern Sweden were sampled for benthic invertebrates using a Surber-sampler, and for each site canopy-cover and pH was obtained.

Genomgång av kemikalieförteckning som exempel på uppströmsarbete : en identifiering av utfasningsämnen i spillvattnet

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

Förbättring av den svenska kiselalgsmetoden-hantering av sedimentering

Benthic diatoms are used in Sweden for monitoring water quality in run-ning water; the method is also frequently used in other countries in Europe. One of the problems of the diatom method is the need for sedimentation of the fresh sample, to be able to decant the over standing water and add alco-hol as a preservations solution. To my knowledge, no results have been published about how long the settling time must be to ensure that the ben-thic diatoms really have settled down to avoid a loss of the diatoms when decanting the over standing water. The aim of my investigation was to improve the Swedish method where the benthic diatoms are used for water quality monitoring. I wanted to find out the appropriate time necessary to wait until all diatoms have settled down before decanting the over standing water. First, fresh benthic diatom samples were taken in the river Fyrisån and the lake Mälaren on different days. After arriving in the laboratory, I waited three different times (30 min, 60 and 180 min) for the diatoms to settle.

Närsalter och bottenlevande organismer i Mönsteråsviken

The focus of this study was to examine the nutrients and benthic organisms of the bay ?Mönsteråsviken?, which is influenced by eutrophication. The purpose was also to look at an interesting gradient forming in the bay, namely the distance from the river outflow of Lillån. At 18 sampling sites in the bay samples of water, sediments and benthic organisms were collected in late April of 2011. The water was analyzed for nitrate, phosphate and chlorophyll.

Nya tillämpningar för utandningstest kopplade till Kibions diagnostikinstrument IRIS ®

The focus of this study was to examine the nutrients and benthic organisms of the bay ?Mönsteråsviken?, which is influenced by eutrophication. The purpose was also to look at an interesting gradient forming in the bay, namely the distance from the river outflow of Lillån. At 18 sampling sites in the bay samples of water, sediments and benthic organisms were collected in late April of 2011. The water was analyzed for nitrate, phosphate and chlorophyll.

Bentiska evertebraters förekomst i källor på Öland

Abstract The benthic macroinvertebrate fauna of 22 natural springs on Öland was sampled, by using a time-standarized kick/sweep sampling technique, in the end of September and early October. The aim was to determine the number of species and their abundances in the macroinvertebrate communities in springs and how/why these may change between different springs. Likewise there was a purpose to investigate possible differences between springs considering the proportions of the number of species and the abundances of the five functional feeding groups; shredders, collectors, filter-feeders, scrapers and predators. There was also an aim to investigate if the distances betweeen springs had any influence on similarity between the communities of benthic macroinvertebrates of the springs. Analysis from the springs collected material showed several interesting patterns in the number of species and their abundances when compared between springs devided into groups depending on their environmental factors such as depth and pH.

Muddring i Ireån : indirekta effekter på bottenfaunan nedströms

This research aims to investigate the effects that dredging may have on benthic fauna. The dredging took place in the stream Ireån on northern Gotland during the early summer 2010. My area of research was taking place in a scenic area downstream in Ireån close to the Baltic Sea. I chose this area due to the dredging that started just upstream of this area and continued further upstream. Thus it is not the direct impact of the dredging that is the focus for this paper but the side-effect the dredging may have on the area downstream.

Små skogliga vattendrag i Värmland - Generell beskrivning, förekomst av traktorspår samt spårens inverkan på bottenfaunan :

Modern forestry requires a high degree of machine traffic for clear felling and scarification operations. The machines most frequently used are big and the traffic often results in tracks on the forest ground. There are many small streams running through a forest, in connection to logging operations, machines might cross these frequently. These crossings could result in the erosion of fine particulate inorganic matter, which ends up in the stream. The aim of this thesis was to give a general description of small forest streams of order-one in the county of Värmland and to determine the frequency of machine tracks in small streams.

Freshwater pearl mussel as indicators of Swedish streams - a comparison between freshwater pearl mussel and biological quality elements

The freshwater pearl mussel (Margaritifera margaritifera) is a large freshwater mussel. Because of its sensitivity to human impact, such as eutrophication, acidification and alterations of hydromorphology, the species is considered as a robust indicator of stream water quality and biodiversity. Moreover, due to the species complex life cycle, including a larval stage on the gills of salmon and trout, and sensitivity of early life stages, regeneration is often used as an indicator. The freshwater pearl mussel is also used in the expert judgement of status classification of benthic invertebrates according to the European Water Framework Directive. The purpose of this study was to gain a deeper understanding of the freshwater pearl mussel as an indicator for Swedish streams. It was made with two types of association analyses.

Sequi : Tredimensionell sequencer

Music production software has a strong tradition of two-dimensional graphical user interface (GUI), in which the time line is represented as a flat composition either horizontally (from left to right) or vertically (from top to bottom). In my degree work titled Sequi, I approach music composition from a different angle. Instead of a two-dimensional time line with only two possibly ways of progression (forward or backward) I constructed a three-dimensional GUI with the maximum of four different ways of progression from any given point in a composition. The height axis is used to describe time-intervals (the time between downbeats) and the wide and depth axes are used to describe progression from one sound to another..

Nätverkandets påverkan på organisationssammansättningen

Networking is an important part, for organizations, in the recruitment process. This since the emergence of Internet networking has become more common and the organizations finds that networking is applied more frequently in the recruitment process. Organizations have noticed that networking often is a more cost efficient option compared to traditional recruitment. Since networking in the recruitment process has increased, we intend to investigate if and how it affects the composition of organizations. This thesis aims to examine networking in the recruiting process, and aims to make no differences between networking offline and online.

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