<p>A solid-phase extraction (SPE) method was developed for the determination of organochlorine pesticides, namely aldrin, alpha-BHC, beta-BHC, delta-BHC, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, lindane, heptachlor, heptachlor epoxide, 4,4’-DDD, 4,4’-DDE and 4,4’- DDT in water. The effect of extraction conditions, such as the addition of sodium chloride and methanol to the sample prior to loading was studied. The sample was concentrated by a plain polystyrene-divinylbenzene resin, and the extract was eluted by ethyl acetate. Qualification and quantification of the target pesticides were performedby gas chromatography/ mass spectrometry (GC/MS) in the full-scan and selected ion-monitoring mode, respectively, and for better detection of pesticides in field samples the mass spectrometer was altered from electron ionization (EI) to chemical ionization mode (CI). The repeatability of the method for MilliQ-water fortified with pesticides at a level of 0.1 to 0.6 µg/l ranged from 8 to 18%, and the obtained recoveries ranged from 67 to 135%. </p><p>The method was evaluated for the determination of organochlorine pesticides in fourteen surface- and groundwater samples taken from locations along King Talal Dam, King Abdullah Canal and Zarqa River in the Jordan Valley. The limit of detection of the pesticides residues in 500-ml field water samples ranged from 0.0009 to 15.7 ng/l. The obtained results confirmed the presence of trace amounts of some organochlorine pesticides in the analyzed samples, i.e. lindane and endosulfan compounds.</p>

<p>Våtmarker som anläggs på jordbruksmark kan förhindra att fosfor från åkrarna når sjöar och vattendrag och hjälper därmed till att minska övergödningen. Det är viktigt att utforma våt-marken på ett sådant sätt att så mycket som möjligt av den biotillgängliga fosforn hålls kvar. Syftet med studien var att undersöka om det finns ett positivt samband mellan lerinnehåll och fosfors biotillgänglighet i en anlagd våtmarks sediment. Syftet var även att undersöka om partikelstorleken minskar gradvis med avståndet från inloppet, det vill säga om mer lera sedimenterar närmare utloppet. Prover togs längs tre transekter från sedimentet i en våtmark i västra Östergötland och fosfor- samt partikelstorleksanalyser gjordes. Genom extraktion med ammoniumklorid (NH4Cl) kunde lättillgänglig fosfor bestämmas. Partikelstorleksanalysen gjordes med en modifierad pipettmetod, baserad på att större partiklar sedimenterar fortare än mindre partiklar. Regressionsanalys visade att partikelstorleken minskade signifikant från inlopp till utlopp i våtmarken. Däremot hittades inte några signifikanta samband mellan partikelstorlek och lättillgänglig fosfor eller totalfosfor, i motsats till resultat i andra studier. Halterna av både lera och olika fosforfraktioner i sedimentet var relativt låga och likartade vid olika provpunkter i våtmarken vilket kan ha påverkat resultaten.</p>

<p>In 1994 a new Forestry Act was accepted in Sweden. One of its aims was to raise the consideration for preservation of biodiversity. Since this happened over 15 years ago there is now an interest in analyzing if the law has been effective in its purpose. In this study methods suitable for analysis are being investigated. The study contents a pilot study of methods for five parameters that can validate if the law has been followed. The fieldstudy were executed in Orsa, Dalarna, Sweden in a managed forest and where last clearcut was done after 1994. The work consisted of measuring the parameters in the field and to compare them with data from before 1994. The benefits of the parameters and the current and previous Forestry Act and their differences are discussed in the report. The parameters examined were the distribution of tree species, standing dead wood, smaller areas saved for preservation, big trees and trees with cavities/cavernous trees. All of these plus a few other variables favourable for the diversity of species in the forest are dealt with in the 30 § in the Forestry Act of 1994. The study implied that the variables reported to be favourable for biodiversity, and possible to investigate within the restrictions of this study, seemed to have increased. The results should however be interpreted with care since the study is small and the reference values sometimes were missing or covering larger areas than the field data.</p>

<p>Riparian vegetation along streams and rivers affects the aquatic community in numerous ways and often operates as a link for energy flux between forest and streams. The studies presented in this licentiate thesis focus on light and terrestrial invertebrates, two factors influenced by riparian zone structure, which potentially affect stream ecosystems and thus also brown trout (Salmo trutta). Paper I is a laboratory experiment where I study size dependent foraging behavior on surface-drifting terrestrial invertebrates and benthic invertebrates by brown trout. The results show a size-dependent difference in foraging ability with large trout being better able to use terrestrial surface prey than small trout. I argue that such ontogenetic foraging differences are due to both morphological constraints (eg. gape limitation) and size dependent behavioral differences related to predation risk. Paper II consists of a 5 month-long 2x2 factorial design field experiment where my objective was to examine the effects of terrestrial invertebrate input and solar radiation (PAR) on different trophic levels in a boreal headwater stream. More specifically, I followed the effects of increased light and decreased terrestrial invertebrate subsidies on periphyton, benthic macroinvertebrates and two size classes of the top fish predator, brown trout. The results showed that the reduction of terrestrial invertebrate input had size- and seasonal-dependent effects on trout, where large trout had lower growth rates than small trout, mainly in summer. Diet analyses of trout supported growth differences in that large trout in unmanipulated enclosures consumed relatively more terrestrial prey than large trout living in enclosures with reduced terrestrial inputs. A higher reliance on terrestrial prey subsidies by large trout compared to small may be explained by ontogenetic differences in foraging and habitat choice. Despite a 2.5-fold increase in PAR, light did not have an effect on chlorophyll a biomass, nor was there an effect on the density or composition of benthic macroinvertebrates. The lack of effects on primary production may be explained by very low nutrient levels in the stream.</p>

<p>Den nya mätningstekniken på marknaden kallas terrester laserskanning. Tekniken bygger på att ett instrument, monterat på ett stativ, sänder ut en laserstråle vilken avlänkas i vertikalled av en spegel samtidigt som det roterar. Laserstrålen reflekteras mot de objekt som befinner sig inom laserskannerns synfält och resulterar i ett punktmoln. Punktmolnet innehåller ofta flera miljoner punkter vilka alla erhåller xyz-koordinater. Tekniken har visat sig lämplig vid dokumentation av byggnader och vid modellering samt kartläggning av industrier och tunnelbyggen.</p><p>Denna studie har genomförts på Sweco VBB i Karlstad i syfte att ta reda på hur lämplig terrester laserskanning är vid vardaglig inmätning och kartering av objekt i stadsmiljö. Metoden har jämförts med traditionell inmätning med totalstation utifrån ett antal frågeställningar. I studien laserskannades två korsningar i Vasastaden, Stockholm. Instrumentet som användes var en IMAGER 5006 av märket Zoller+Fröhlich. De totalt sex stycken skanningarna resulterade i punktmoln vilka georefererades genom att måltavlor mättes in med totalstation. Efterbearbetningen bestod av registrering, redigering och reducering av punktmolnen. Genom manuell tolkning av punktmolnen och med hjälp av verktyget Virtual Surveyor i Leica Geosystems programvara Cyclone, kunde olika objekt mätas in och kartläggning av de båda korsningarna ske.</p><p>En generell jämförelse mellan terrester laserskanning och totalstation visar att laserskanning är en snabb metod som ger stora mängder data med hög detaljrikedom, medger en större säkerhet i fält och ger enorma möjligheter för visualisering, modellering och skapande av terrängmodeller. Laserskanning är dock en dyr metod som ger en något sämre noggrannhet och som ännu inte klarar att mäta sträckor över hundra meter. Metoden kräver också totalstation (eller GPS) för georeferering. Studien har också visat att tidsvinsten som uppkommer i fält förloras genom tidsödande efterbearbetning och manuell tolkning av punktmolnet. Trots detta använder idag ett flertal företag denna metod vid inmätning. Slutsatserna pekar främst på att laserskanning som inmätningsmetod lämpar sig bäst över små områden där antalet objekt är högt och där säkerheten i fält är viktig. Dock ses metoden mer som ett komplement till totalstationen genom de möjligheter som erbjuds via visualisering och modellering och därmed inte en ersättare för den senare.</p> / <p>A new technique for surveying is the terrestrial laser scanning. The technique is based on an instrument, mounted on a tripod, emitting a laser pulse which is vertically deflected by a mirror while rotating. The laser pulse is reflected by the objects within the field of view of the laser scanner. The laser scan results in a point cloud most often containing several millions of points which all have XYZ-coordinates. The technique has proven its benefits when documenting buildings, modelling and surveying of industries and tunnels.</p><p>This study has been carried out at Sweco VBB in Karlstad in purpose of finding out how suitable terrestrial laser scanning is for everyday surveying in urban environment. The method has been compared with traditional surveying with total station from a number of questions. In the study two crossings in Vasastaden, Stockholm, were scanned. The instrument used was an IMAGER 5006 from Zoller+Fröhlich. The 6 scannings resulted in point clouds which were georeferenced by using targets and a total station. The post processing consisted of registering, editing and reducing the point clouds. Through manual interpretation of the point clouds and by using the tool Virtual Surveyor in the program Cyclone by Leica Geosystems it was possible to survey different objects at the crossings.</p><p>A general comparison between terrestrial laser scanning and total station shows that laser scanning is a rapid method producing large amounts of data with a high level of details, allows higher security in field and gives enormous possibilities for visualisation, modelling and creating of terrain models. However, laser scanning is an expensive method which gives a slightly lower accuracy and yet cannot be used for longer distances. The method also demands total station (or GPS) for georeferencing. The study has also shown that the saving of time in field is lost by time consuming post processing and manual interpretation of the point cloud. Nonetheless this method is used by several companies for everyday surveying. The conclusions advert mostly that laser scanning is best suitable for small areas where the number of objects is high and where security in field is important. Nevertheless, the method should be seen more as a compliment to the total station because of the possibilities offered by visualisation and modelling and therefore not as a replacement for the latter.</p>

<ul><li>Energiflöden mellan terrestra och akvatiska ekosystem har uppmärksammats mycket den senaste tiden. I den här studien undersöker jag betydelsen av ett terrestert djur, älgen (<em>Alces alces</em>), som dör i vattendrag och avger näring till vattnet. Genom litteraturstudier och teoretiska beräkningar uppskattade jag hur vanligt det är att älgar dör i vattendrag och om dessa älgar har någon inverkan på vattendragets totala näringsbudget. Jag fann att drunkning hos älgar tas upp som en parameter för naturliga dödsorsaker i flera artiklar från USA, Canada och Polen. Orsakerna till att älgar drunknar, trots att de är duktiga simmare, kan vara t.ex. att stranden är för brant, att de tvingas ner i vattnet av rovdjur, att skadeskjutna älgar söker sig till vatten på grund av törstkänningar i samband med blodförlust eller att de går igenom svaga isar. Utifrån teoretiska beräkningar fann jag även att en älg som dött i ett vattendrag bidrar till mycket liten del av den totala näringsbudgeten. Min hypotes är att det endast blir en lokal påverkan nedströms djuret. Hur denna påverkan ser ut och om den kommer primärproducenter och fiskar tillgodo är mycket komplext och undersöks inte i denna studie.</li></ul>

No description available.

<p>The climate change is expected to affect especially alpine areas negatively, replacing the alpine flora with subalpine forest. The understanding of how vegetation influences total organic carbon (TOC) in soil, streams and lakes in alpine and subalpine areas will lead to a better understanding of the effects of climate change, and will also increase the knowledge of the ecotone as a whole. In this study plant-soil relations were examined in a subalpine and an alpine catchment in the north of Sweden, by comparing dissolved organic carbon (DOC) concentrations, 13C-DOC, 13 compared with lake and stream water DOC, as well as sediment OC from the recipient lakes in the catchments.</p><p> The results show that subalpine forests at lower altitudes, have higher DOC concentrations, higher C:N ratios, and more depleted Particulate OM in water and inlets, show that allochthonous carbon influences water properties in both catchments, as does primary production by benthic and pelagic algae, separating shallow and deep sediment Differences between the catchments are explained with the higher primary production of organic material and root exudations from trees in the subalpine forested catchment effecting the whole catchment dynamics. C-SOM and the carbon to nitrogen (C:N) ratios. The terrestrial bulk chemical properties of DOC were alsoδ13C signals in soil, and soil-solution compared to alpine areas. δ13C signals from Dissolved OM andδ13C signals.</p>

<p>Virtually all diurnal birds have tetrachomatic vision based on four different colour receptors. As a result, birds are potentially able to perceive their environment in twice as many colours as humans and four times as many colours compared to most other mammals, which are dichromatic. In addition to the spectrum visible to humans, birds are able to detect ultraviolet (UV) light. Signals with a UV component have been shown to be important to birds both in foraging and colour signalling. Because of the superior colour discrimination of the avian eye, UV sensitivity, but especially owing to its tetrachromacy, we cannot know what birds look like to those that matter, i.e. other birds.</p><p>In my thesis I describe a new molecular method with which it is possible to identify the vision system of birds only using a small amount of DNA, without the need to keep or sacrifice the animal. It thereby facilitates large screenings, including rare and endangered species. The method has been used to increase the number of species with identified vision system type from 19 to 66. I show that raptors and songbirds have different vision systems, giving songbirds the possibility of a secret channel for colour signalling, and that male songbirds in coniferous forest take advantage of this to be significantly more cryptic to raptors than to females songbirds. I show that gulls have gained a vision system enabling them to detect the UV signals of fish when the fish swim close to the surface.</p><p>Even though we tend to be rather self-satisfied with the quality of our colour vision, we are colour-blind when compared to birds. My work shows that human colour vision is inadequate for judging animal coloration, and that there is much more going on in bird colour signalling than meets our eye.</p>

Abiotic and biotic variation has been shown to be important in regulating nutrient cycling and belowground communities in natural systems. However, genetic variation in dominant plants as a driver of rates of nutrient cycling is still poorly understood and few studies have looked at genotype interactions across multiple environments. Using Populus angustifolia and a common garden approach, we hypothesized that all three factors: tree genetic variation, environmental conditions and genetic by environment (G x E) interactions would affect soil carbon (C) storage and nitrogen (N) cycling. Replicated copies of five different reciprocally planted Populus genotypes were studied in three separate 18-21 year old common gardens at different elevations (1300m, 1384m and 1587m) in northern Utah, to measure the genotype and environmental effects on pools of soil C and N as well as rates of soil net N nitrification and net mineralization. Our results indicate that genotypes influence pools of soil C, total N and C:N, but genotype did not influence net rates of nitrogen mineralization. Environmental variation significantly influenced pools of soil C, total N, soil C:N and rates of net nitrification and net N mineralization. As predicted, G x E interactions significantly influenced both pools and processes of soil C and N cycling. Overall, we found that genetic variation in plant traits (tree diameter and leaf/root chemistry) as well as soil texture across gardens were significant predictors of soil C and N pools and fluxes across seasons. These data help us understand the relative role of genotypic variation on above- and belowground interactions in different environments and the consequences of these interactions on ecosystem processes. The results from this study show that across an environmental gradient Populus angustifolia genotypes can influence nitrogen mineralization through feedbacks between environmental variation, tree phenotype and soils.