The fate of the carbon and nitrogen in dairy farm effluent (DFE) applied onto soil was investigated through laboratory experiments and field lysimeter studies. They resulted in the development and testing of a complex carbon (C) and nitrogen (N) simulation model (CaNS-Eff) of the soil-plant-microbial system. To minimise the risk of contamination of surface waters, regulatory authorities in New Zealand promote irrigation onto land as the preferred treatment method for DFE. The allowable annual loading rates for DFE, as defined in statutory regional plans are based on annual N balance calculations, comparing N inputs to outputs from the farming system. Little information is available, however, to assess the effects that these loading rates have on the receiving environment. It is this need, to understand the fate of land-applied DFE and develop a tool to describe the process, that is addressed in this research. The microbially mediated net N mineralisation from DFE takes a central role in the turnover of DFE, as the total N in DFE is dominated by organic N. In a laboratory experiment, where DFE was applied at the standard farm loading rate of 68 kg N ha⁻¹, the net C mineralisation from the DFE was finished 13 days after application and represented 30% of the applied C, with no net N mineralisation being measured by Day 113. The soluble fraction of DFE appeared to have a microbial availability similar to that of glucose. The low and gradually changing respiration rate measured from DFE indicated a semi-continuous substrate supply to the microbial biomass, reflecting the complex nature and broad range of C compounds in DFE. The repeated application of DFE will gradually enhance the mineralisable fraction of the total soil organic N and in the long term increase net N mineralisation. To address the lack of data on the fate of faecal-N in DFE, a ¹⁵N-labelled faecal component of DFE was applied under two different water treatments onto intact soil cores with pasture growing on them. At the end of 255 days, approximately 2% of the applied faecal ¹⁵N had been leached, 11 % was in plant material, 11 % was still as effluent on the surface, and 40% remained in the soil (39% as organic N). Unmeasured gaseous losses and physical losses from the soil surface of the cores supposedly account for the remaining ¹⁵N (approximately 36%). Separate analysis of the total and ammonium nitrogen contents and ¹⁵N enrichments of the DFE and filtered sub-samples (0.5 mm, 0.2µm) showed that the faecal-N fraction was not labelled homogeneously. Due to this heterogeneity, which was exacerbated by the filtration of DFE on the soil surface, it was difficult to calculate the turnover of the total faecal-N fraction based on ¹⁵N results. By making a simplifying assumption about the enrichment of the ¹⁵N in the DFE that infiltrated the soil, the contribution from DFE-N to all plant available N fractions including soil inorganic N was estimated to have been approximately 11 % of the applied DFE-N. An initial two-year study investigating the feasibility of manipulating soil water conditions through controlled drainage to enhance denitrification from irrigated DFE was extended a further two years for this thesis project. The resulting four-year data set provided the opportunity to evaluate the sustainability of DFE application onto land, an extended data set against which to test the adequacy of CaNS-Eff, and to identify the key processes in the fate of DFE irrigated onto soil under field conditions. In the final year of DFE irrigation, 1554 kg N ha⁻¹ of DFE-N was applied onto the lysimeters, with the main removal mechanism being pasture uptake (700 kg N ha⁻¹ yr⁻¹ removed). An average of 193 kg N ha⁻¹ yr⁻¹ was leached, with 80% of this being organic N. The nitrate leaching decreased with increasing soil moisture conditions through controlled drainage. At the high DFE loading rate used, the total soil C and N, pH and the microbial biomass increased at different rates over the four years. The long-term sustainability of the application of DFE can only be maintained when the supply of inorganic N is matched by the demand of the pasture. The complex simulation model (CaNS-Eff) of the soil-plant-microbial system was developed to describe the transport and transformations of C and N components in effluents applied onto the soil. The model addresses the shortcomings in existing models and simulates the transport, adsorption and filtration of both dissolved and particulate components of an effluent. The soil matrix is divided into mobile and immobile flow domains with convective flow of solutes occurring in the mobile fraction only. Diffusion is considered to occur between the micropore and mesopore domains both between and within a soil layer, allowing dissolved material to move into the immobile zone. To select an appropriate sub-model to simulate the water fluxes within CaNS-Eff, the measured drainage volumes and water table heights from the lysimeters were compared to simulated values over four years. Two different modelling approaches were compared, a simpler water balance model, DRAINMOD, and a solution to Richards' equation, SWIM. Both models provided excellent estimation of the total amount of drainage and water table height. The greatest errors in drainage volume were associated with rain events over the summer and autumn, when antecedent soil conditions were driest. When soil water and interlayer fluxes are required at small time steps such as during infiltration under DFE-irrigation, SWIM's more mechanistic approach offered more flexibility and consequently was the sub-model selected to use within CaNS-Eff. Measured bromide leaching from the lysimeters showed that on average 18% of the bromide from an irrigation event bypassed the soil matrix and was leached in the initial drainage event. This bypass mechanism accounted for the high amount of organic N leached under DFE-irrigation onto these soils and a description of this bypass process needed to be included in CaNS-Eff. Between 80 and 90% of the N and C leached from the lysimeters was particulate (> 0.2 µm in size), demonstrating the need to describe transport of particulate material in CaNS-Eff. The filtration behaviour of four soil horizons was measured by characterising the size of C material in a DFE, applying this DFE onto intact soil cores, and collecting and analyzing the resulting leachate using the same size characterisation. After two water flushes, an average of 34% of the applied DFE-C was leached through the top 0-50 mm soil cores, with a corresponding amount of 27% being leached from the 50-150 mm soil cores. Most of the C leaching occurred during the initial DFE application onto the soil. To simulate the transport and leaching of particulate C, a sub-model was developed and parameterised that describes the movement of the effluent in terms of filtering and trapping the C within a soil horizon and then washing it out with subsequent flow events. The microbial availability of the various organic fractions within the soil system are described in CaNS-Eff by availability spectra of multiple first-order decay functions. The simulation of microbial dynamics is based on actual consumption of available C for three microbial biomass populations: heterotrophs, nitrifiers and denitrifiers. The respiration level of a population is controlled by the amount of C that is available to that population. This respiration rate can vary between low level maintenance requirements, when very little substrate is available, and higher levels when excess substrate is available to an actively growing population. The plant component is described as both above and below-ground fractions of a rye grass-clover pasture. The parameter set used in CaNS-Eff to simulate the fate of DFE irrigated onto the conventionally drained lysimeter treatments over three years with a subsequent 10 months non-irrigation period was derived from own laboratory studies, field measurements, experimental literature data and published model studies. As no systematic calibration exercise was undertaken to optimise these parameters, the parameter set should be considered as "initial best estimates" and not as a calibrated data set on which a full validation of CaNS-Eff could be based. Over the 42 months of simulation, the cumulative drainage from CaNS-Eff for the conventionally drained DFE lysimeter was always within the 95% CI of the measured value. On the basis of individual drainage bulking periods, CaNS-Eff was able to explain 92% of the variation in the measured drainage volumes. On an event basis the accuracy of the simulated water filled pore space (WFPS) was better than that of the drainage volume, with an average of 70% of the simulated WFPS values being within the 95% CI for the soil layers investigated, compared to 44% for the drainage volumes. Overall the hydrological component of CaNS-Eff, which is based on the SWIM model, could be considered as satisfactory for the purposes of predicting the soil water status and drainage volume from the conventionally drained lysimeter treatment for this study. The simulated cumulative nitrate leaching of 4.7 g NO₃-N m⁻² over the 42 months of lysimeter operation was in good agreement to the measured amount of 3.0 (± 2.7) g NO₃-N m⁻². Similarly, the total simulated ammonium leaching of 2.7g NH₄- N m⁻² was very close to the measured amount of 2.5 (± 1.35) g NH₄- N m⁻² , however the dynamics were not as close to the measured values as with the nitrate leaching. The simulated amount of organic N leached was approximately double that measured, and most of the difference originated from the simulated de-adsorption of the dissolved fraction of organic N during the l0-month period after the final DFE irrigation. The 305 g C m⁻² of simulated particulate C leached was close to the measured amount of 224 g C m⁻² over the 31 months of simulation. The dissolved C fraction was substantially over-predicted. There was good agreement in the non-adsorbed and particulate fractions of the leached C and N in DFE. However, the isothermic behaviour of the adsorbed pools indicated that a non-reversible component needed to be introduced or that the dynamics of the de-adsorption needed to be improved. Taking into account that the parameters were not calibrated but only "initial best estimates", the agreement in the dynamics and the absolute amounts between the measured and simulated values of leached C and N demonstrated that CaNS-Eff contains an adequate description of the leaching processes following DFE irrigation onto the soil. The simulated pasture N production was in reasonable agreement with the measured data. The simulated dynamics and amounts of microbial biomass in the topsoil layers were in good agreement with the measured data. This is an important result as the soil microbial biomass is the key transformation station for organic materials. Excepting the topsoil layer, the simulated total C and N dynamics were close to the measured values. The model predicted an accumulation of C and N in the topsoil layer as expected, but not measured. Although no measurements were available to compare the dynamics and amounts of the soil NO₃-N and NH₄-N, the simulated values appear realistic for an effluent treatment site and are consistent with measured pasture data. Considering the large amount of total N and C applied onto the lysimeters over the 42 months of operation (4 t ha⁻¹ of N and 42 t ha⁻¹0f C), the various forms of C and N in dissolved and particulate DFE as well as in returned pasture, and that the parameters used in the test have not been calibrated, the simulated values from CaNS-Eff compared satisfactorily to the measured data.

<p>This investigation strives to determine the level of ecodesign awareness as well as to map the use of methods and tools for this concept in the electrical and electronics industries of Thailand.</p><p>The foundation of the thesis is eight semi-structured qualitative research interviews performed with various people at Thai organisations, an electronics manufacturer in Thailand, and experts from Swedish, Danish and Thai universities. The research method has yielded the following results:</p><p>The level of ecodesign awareness within the country is low, and so is the general level of environmental knowledge. The concept of Life Cycle thinking is mostly unknown, and at best used only to parts of its full potential. The ecodesign education is limited to basic courses at university level and much of the problems with the use of methods and tools for ecodesign can be traced to the lack of ecodesign knowledge amongst its presumptive users. Respondents of this research suggests that the ecodesign knowledge and awareness is significantly higher amongst larger companies with foreign connections than it is amongst Small and Medium sized Enterprises of Thailand, which often have no such contacts.</p><p>At present, efforts are being made to educate Thai companies in ecodesign through networking, seminars, workshops and student/expert internships. These endeavours have been arranged by various organizations with the aid from foreign experts and have resulted in successful ecodesign/redesign of products within Thailand.</p><p>Stakeholder demands such as cost-down or legislation compliance demands are the main driving forces for ecodesign in Thailand, and very few attempts at ecodesign for the pure benefit of the environment are being made.</p><p>Present trends suggest that the future of ecodesign in Thailand will include the finalisation of a Thai-RoHS directive and possibly further work on a Thai-WEEE directive as well.</p><p>As for Life Cycle thinking, practices of Life Cycle Assessment (LCA) are still basic, but some uses of such LCA tools as SimaPro and GaBi have been proven. Commercial LCA software licenses are considered expensive by most Thai companies and it has become common practice to utilize licenses bought by organisations instead of buying licenses for one’s own company. This results in high costs having to be carried by the organisations and diminishes investment possibilities in other ecodesign fields. At current, LCI data is being requested by companies and might lead to more work being made in this area in the future.</p><p>In conclusion, more effort needs to be put into education on all levels and the application of educational methods and tools is advised.</p><p> </p>

This investigation strives to determine the level of ecodesign awareness as well as to map the use of methods and tools for this concept in the electrical and electronics industries of Thailand. The foundation of the thesis is eight semi-structured qualitative research interviews performed with various people at Thai organisations, an electronics manufacturer in Thailand, and experts from Swedish, Danish and Thai universities. The research method has yielded the following results: The level of ecodesign awareness within the country is low, and so is the general level of environmental knowledge. The concept of Life Cycle thinking is mostly unknown, and at best used only to parts of its full potential. The ecodesign education is limited to basic courses at university level and much of the problems with the use of methods and tools for ecodesign can be traced to the lack of ecodesign knowledge amongst its presumptive users. Respondents of this research suggests that the ecodesign knowledge and awareness is significantly higher amongst larger companies with foreign connections than it is amongst Small and Medium sized Enterprises of Thailand, which often have no such contacts. At present, efforts are being made to educate Thai companies in ecodesign through networking, seminars, workshops and student/expert internships. These endeavours have been arranged by various organizations with the aid from foreign experts and have resulted in successful ecodesign/redesign of products within Thailand. Stakeholder demands such as cost-down or legislation compliance demands are the main driving forces for ecodesign in Thailand, and very few attempts at ecodesign for the pure benefit of the environment are being made. Present trends suggest that the future of ecodesign in Thailand will include the finalisation of a Thai-RoHS directive and possibly further work on a Thai-WEEE directive as well. As for Life Cycle thinking, practices of Life Cycle Assessment (LCA) are still basic, but some uses of such LCA tools as SimaPro and GaBi have been proven. Commercial LCA software licenses are considered expensive by most Thai companies and it has become common practice to utilize licenses bought by organisations instead of buying licenses for one’s own company. This results in high costs having to be carried by the organisations and diminishes investment possibilities in other ecodesign fields. At current, LCI data is being requested by companies and might lead to more work being made in this area in the future. In conclusion, more effort needs to be put into education on all levels and the application of educational methods and tools is advised.

Τα τελευταία χρόνια χαρακτηρίζονται από μια αλματώδη ανάπτυξη των προϊόντων και υπηρεσιών που βασίζονται στα δίκτυα ασύρματης επικοινωνίας, ενώ προκύπτουν σημαντικές ερευνητικές προκλήσεις. Τα συστήματα πολλαπλών κεραιών στον πομπό και στο δέκτη, γνωστά και ως συστήματα MIMO (multi-input multi-output), καθώς και η τεχνολογία πολλαπλής προσπέλασης με χρήση κωδικών (code division multiple access, CDMA) αποτελούν δύο από τα βασικά μέτωπα ανάπτυξης των ασύρματων τηλεπικοινωνιών. Στα πλαίσια της παρούσας διδακτορικής διατριβής, ασχοληθήκαμε με την ανάπτυξη και μελέτη αλγορίθμων επεξεργασίας σήματος για τα δύο παραπάνω συστήματα, όπως περιγράφεται αναλυτικά παρακάτω. Σχετικά με τα συστήματα MIMO, η πρωτοποριακή έρευνα που πραγματοποιήθηκε στα Bell Labs γύρω στα 1996, όπου αναπτύχθηκε η αρχιτεκτονική BLAST (Bell Labs Layered Space-Time), απέδειξε ότι η χρήση πολλαπλών κεραιών μπορεί να οδηγήσει σε σημαντική αύξηση της χωρητικότητας των ασύρματων συστημάτων. Προκειμένου να αξιοποιηθούν οι παραπάνω δυνατότητες, απαιτείται η σχεδίαση σύνθετων δεκτών MIMO. Προς αυτήν την κατεύθυνση, έχει προταθεί ένας μεγάλος αριθμός μεθόδων ισοστάθμισης του καναλιού. Ωστόσο, οι περισσότερες από αυτές υποθέτουν ότι το ασύρματο κανάλι είναι: 1) χρονικά σταθερό, 2) συχνοτικά επίπεδο (δεν εισάγει διασυμβολική παρεμβολή), και κυρίως 3) ότι είναι γνωστό στο δέκτη. Δεδομένου ότι σε ευρυζωνικά συστήματα μονής φέρουσας οι παραπάνω υποθέσεις είναι δύσκολο να ικανοποιηθούν, στραφήκαμε προς τις προσαρμοστικές μεθόδους ισοστάθμισης. Συγκεκριμένα, αναπτύξαμε τρεις βασικούς αλγορίθμους. Ο πρώτος αλγόριθμος αποτελεί έναν προσαρμοστικό ισοσταθμιστή ανάδρασης αποφάσεων (decision feedback equalizer, DFE) για συχνοτικά επίπεδα κανάλια ΜΙΜΟ. Ο προτεινόμενος MIMO DFE ακολουθεί την αρχιτεκτονική BLAST, και ανανεώνεται με βάση τον αλγόριθμο αναδρομικών ελαχίστων τετραγώνων (RLS) τετραγωνικής ρίζας. Ο ισοσταθμιστής μπορεί να παρακολουθήσει ένα χρονικά μεταβαλλόμενο κανάλι, και, από όσο γνωρίζουμε, έχει τη χαμηλότερη πολυπλοκότητα από όλους τους δέκτες BLAST που έχουν προταθεί έως σήμερα. Ο δεύτερος αλγόριθμος αποτελεί την επέκταση του προηγούμενου σε συχνοτικά επιλεκτικά κανάλια. Μέσω κατάλληλης μοντελοποίησης του προβλήματος ισοστάθμισης, οδηγηθήκαμε σε έναν αποδοτικό DFE για ευρυζωνικά κανάλια MIMO. Τότε, η διαδικασία της ισοστάθμισης εμφανίζει προβλήματα αριθμητικής ευστάθειας, που λόγω της υλοποίησης RLS τετραγωνικής ρίζας αντιμετωπίστηκαν επιτυχώς. Κινούμενοι προς την κατεύθυνση περαιτέρω μείωσης της πολυπλοκότητας, προτείναμε έναν προσαρμοστικό MIMO DFE που ανανεώνεται με βάση τον αλγόριθμο ελαχίστων μέσων τετραγώνων (LMS) υλοποιημένο εξ ολοκλήρου στο πεδίο της συχνότητας. Με χρήση του ταχύ μετασχηματισμού Fourier (FFT), μειώνεται η απαιτούμενη πολυπλοκότητα. Παράλληλα, η μετάβαση στο πεδίο των συχνοτήτων έχει ως αποτέλεσμα την προσεγγιστική διαγωνοποίηση του συστήματος, προσφέροντας ανεξάρτητη ανανέωση των φίλτρων ανά συχνοτική συνιστώσα και επιτάχυνση της σύγκλισης του αλγορίθμου. Ο προτεινόμενος ισοσταθμιστής πετυχαίνει μια καλή ανταλλαγή μεταξύ απόδοσης και πολυπλοκότητας. Παράλληλα με τα παραπάνω, ασχοληθήκαμε με την εκτίμηση του ασύρματου καναλιού σε ένα ασύγχρονο σύστημα CDMA. Το βασικό σενάριο είναι ότι ο σταθμός βάσης γνωρίζει ήδη τους ενεργούς χρήστες, και καλείται να εκτιμήσει τις παραμέτρους του καναλιού ανερχόμενης ζεύξης ενός νέου χρήστη που εισέρχεται στο σύστημα. Το πρόβλημα περιγράφεται από μια συνάρτηση ελαχίστων τετραγώνων, η οποία είναι γραμμική ως προς τα κέρδη του καναλιού, και μη γραμμική ως προς τις καθυστερήσεις του. Αποδείξαμε ότι το πρόβλημα έχει μια προσεγγιστικά διαχωρίσιμη μορφή, και προτείναμε μια επαναληπτική μέθοδο υπολογισμού των παραμέτρων. Ο προτεινόμενος αλγόριθμος δεν απαιτεί κάποια ειδική ακολουθία διάχυσης και λειτουργεί αποδοτικά ακόμη και για περιορισμένη ακολουθία εκπαίδευσης. Είναι εύρωστος στην παρεμβολή πολλαπλών χρηστών και περισσότερο ακριβής από μια υπάρχουσα μέθοδο εις βάρος μιας ασήμαντης αύξησης στην υπολογιστική πολυπλοκότητα. / Over the last decades, a dramatic progress in the products and services based on wireless communication networks has been observed, while, at the same time, new research challenges arise. The systems employing multiple antennas at the transmitter and the receiver, known as MIMO (multi-input multi-output) systems, as well as code division multiple access (CDMA) systems, are two of the main technologies employed for the evolution of wireless communications. During this PhD thesis, we worked on the design and analysis of signal processing algorithms for the two above systems, as it is described in detail next. Concerning the MIMO systems, the pioneering work performed at Bell Labs around 1996, where the BLAST (Bell Labs Layered Space-Time) architecture has been developed, proved that by using multiple antennas can lead to a significant increase in wireless systems capacity. To exploit this potential, sophisticated MIMO receivers should be designed. To this end, a large amount of channel equalizers has been proposed. However, most of these methods assume that the wireless channel is: 1) static, 2) frequency flat (no intersymbol interference is introduced), and mainly 3) it is perfectly known at the receiver. Provided that in high rate single carrier systems these assumptions are difficult to be met, we focused our attention on adaptive equalization methods. More specifically, three basic algorithms have been developed. The first algorithm is an adaptive decision feedback equalizer (DFE) for frequency flat MIMO channels. The proposed MIMO DFE implements the BLAST architecture, and it is updated by the recursive least squares (RLS) algorithm in its square root form. The new equalizer can track time varying channels, and, to the best of our knowledge, it has the lowest computational complexity among the BLAST receivers that have been proposed up to now. The second algorithm is an extension of the previous one to the frequency selective channel case. By proper modeling of the equalization problem, we arrived at an efficient DFE for wideband MIMO channels. In this case, the equalization process encounters numerical instability problems, which were successfully treated by the square root RLS implementation employed. To further reduce complexity, we proposed an adaptive MIMO DFE that is updated by the least mean square (LMS) algorithm, fully implemented in the frequency domain. By using the fast Fourier transform (FFT), the complexity required is considerably reduced. Moreover, the frequency domain implementation leads to an approximate decoupling of the equalization problem at each frequency bin. Thus, an independent update of the filters at each frequency bin allows for a faster convergence of the algorithm. The proposed equalizer offers a good performance - complexity tradeoff. Furthermore, we worked on channel estimation for an asynchronous CDMA system. The assumed scenario is that the base station has already acquired all the active users, while the uplink channel parameters of a new user entering the system should be estimated. The problem can be described via a least squares cost function, which is linear with respect to the channel gains, and non linear to its delays. We proved that the problem is approximately decoupled, and a new iterative parameter estimation method has been proposed. The suggested method does not require any specific pilot sequence and performs well even for a short training interval. It is robust to multiple access interference and more accurate compared to an existing method, at the expense of an insignificant increase in computational complexity.

Eco-design is relatively new and fast growing field of research due to its vital importance to the manufacturing industry and its related environmental issues such as reducing waste, and CO2 emission. A major EU programme relating to the environment is the waste of Electrical and Electronic Equipment (WEEE) directive. The (WEEE) directive specifies ten categories and a voltage range which is up to 1.000 volts AC or 1.500volts DC. The developed framework came for the implementation of Eco-design principles that helps to take into account the adaption of the (WEEE) directive and the restriction of hazard substances (RoHS) used in electrical and electronic equipments. As a result of identify gaps and needs such as a lack of a comprehensive Eco-design framework and the need to integrate it to the normal business operation. In this research the PDCA framework for Eco-design and WEEE directive will be discussed. The framework will encompass all of the Eco-design¿s implementation and integration factors and activities such as WEEE and RoHS directives, Eco-design management, Environmental legislations, Eco-design tools and considerations. The literature review covers the topic of Eco-design¿s related issues, and WEEE and RoHS directives rules. Based on comprehensive questionnaire survey of Eco-design, WEEE and RoHS issues and activities among a sample of environmentally aware companies, statistical analysis is carried out using SPSS software. Then the findings of the survey triangulated with the findings of the literature review formed the basis of the design and implementation plan of the proposed framework

A two-year lysimeter study was undertaken to compare the environmental effects (e.g. nitrate leaching and nitrous oxide emissions) of soil applied lactose-depleted dairy factory effluent (LD-DFE) with lactose-rich DFE. The aim of this experiment was to determine the fate of nitrogen from LD-DFE and dairy cow urine applied to a Templeton fine sandy loam soil (Udic Ustrochrept), supporting a herbage cover of ryegrass (Lolium perenne) and white clover (Trifolium repens). Measurements were carried out on the amount of nitrogen lost from the soil via leaching, lost by denitrification, removed by the pasture plants, and immobilized within the soil organic fraction. Further, a comparison between the fate of nitrogen in LD-DFE irrigated onto land under a "cut and carry" system, as opposed to a "grazed" pasture system was undertaken. Lactose-depleted dairy factory effluent was applied at three-weekly intervals during the summer months at rates of 25 and 50 mm, until nitrogen loading targets of 300 and 600 kg N ha⁻¹ yr⁻¹ had been achieved. Measured leaching losses of nitrogen averaged 2 and 7 kg N ha⁻¹ yr⁻¹ for Control 25 and Control 50 treatments; 21, 20 and 58 kg N ha⁻¹ yr⁻¹ for 25 and 50 mm "cut and carry" treatments respectively; and 96 kg N ha⁻¹ yr⁻¹ for the 25 mm "grazed" treatment. The range of nitrate-N leaching loss from LD-DFE plus urine is no different from the lactose-rich DFE nitrate leaching loss. Uptake of nitrogen by the growing pasture averaged 153, 184,340,352,483, and 415 kg N ha⁻¹ yr⁻¹ for Control 25, Control 50, LD-DFE 25 and LD-DFE 50 mm "cut and carry" treatments, and the LD-DFE 25 mm "grazed" treatment, respectively. Denitrification losses were 0.06, 4.4, 1.69, 19.70, and 7.4 kg N ha⁻¹ yr⁻¹ for Control 25, the LD-DFE 25 "cut and carry" treatments, the LD-DFE 25 mm "grazed" treatment, and calculated "paddock losses", respectively. Isotopic nitrogen studies found that 29.4 and 25.8% of applied LD-DFE nitrogen was immobilised in the LD-DFE 25 and LD-DFE 50 "cut and carry" treatments. The results of this experiment confirm the findings of the previous lactose-rich DFE study, in that the effects of grazing stock are of greater environmental concern than the removal of lactose from the effluent waste stream.

Boreal forests are particularly vulnerable to climate change, experiencing a much more drastic increase in temperatures and having a limited amount of more northern refugia. The trees making up these vast and important ecosystems already had to adapt previously to environmental pressures brought about by the repeated glaciations during past ice ages. Studying the patterns of adaption of these trees can thus provide valuable insights on how to mitigate future damage. This thesis presents and analyses population structure, demo- graphic history and the distribution of fitness effects (DFE) of the diploid Betula pendula and tetraploid B. pubescens across Scandinavia. Birches–being widespread in boreal forests as well as having great economical importance–constitute superb model species. The analyses of this work confirm the expectations on postglacial population expansion and diploid-tetraploid introgression. They furthermore ascertain the presence of two genetic clusters and a remarkably similar DFE for the species. This work also contributes with a transparent, reproducible and reusable pipeline which facilitates running similar analyses for related species.