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To improve the properties of thermochemical heat storage materials, salt mixtures were evaluated for their heat storage capacity and cycle stability as part of the innovation incubator project “Thermochemical battery” of the Leuphana university Lüneburg. Based on naturally occurring compound minerals, 16 sulfates, 18 chlorides and 5 chloride multi-mixtures, 18 bromides and 5 intermixtures between sulfates, chlorides and bromides were synthesized either from liquid solution or by dry mixing for TGA/DSC screening before continuing the heat storage evaluation with five different measurement setups at a laboratory scale. The TGA/DSC analysis served as a screening process to reduce the number of testing materials for the upscaled experiments. The evaluation process consisted of a three-cycle dehydration/hydration measurement at Tmax = 100°C and Tmax = 200°C. In case of the bromide samples a measurement of hydration conditions with Tmax = 110°C and a water flow at e = 18.68mbar, were added to the procedure to detect the maximum water uptake temperature. Also, a single dehydration to a temperature of Tmax = 500°C was implemented to observe melting behavior and to easier calculate the samples’ stages of hydration from the remaining anhydrous mass. Materials which showed high energy storage density and improved cycle stability during this first evaluation were cleared for multi-cycle measurements of 10 to 25 dehydration and hydration cycles at Tmax = 100 to 120°C and the evaluations at m = 20 to 100g scale. An estimate for the specific heat capacities at different temperatures of the materials which passed the initial stage was calculated from the TGA/DSC results as well. The laboratory scale measurement setup went through five stages of refining, which led to reducing the intended maximum sample mass from m = 100g to m = 20g. A switch from supplied liquid water to water vapor as the used reactant was also implemented in exchange for improved dehydration conditions. Introducing a vacuum pump for evaporating the water limited the influence of outside heat sources during hydration and in-situ dehydration was enabled as to not disturb the state the samples were settling in between measurements. Baseline calculation from blanc measurements with glass powder and attempts to calculate the specific heat capacity cp of the tested materials by 6 applying the Joule-Lenz-law to the measurement apparatus was another step of method development. The evaluation process of the laboratory scale tests at the final setting consisted of 1 to 5 cycle measurements of in-situ dehydration and hydrations with applied vacuum for t = 30 minutes at p ~ 30mbar. Upscaling the sample mass to m = 20g allowed for a close observation of different material behaviors. Agglomeration, melting and dissolving of the m = 10mg samples during the TGA/DSC analysis can be deducted from the recorded measurement curves and the state of the sample after measurement. However, at laboratory scale the visible volume changes, observed sample consistency after agglomeration and an automatic removal of molten and dissolved sample mass during the measurement allowed for a better characterization and understanding of the magnitude of the actual changes. This was done for the first time, particularly for mixed salts. Of the original number of 62 samples, 4 mixtures which passed the initial TGA/DSC screening namely {2MgCl2+ KCl}, {2MgCl2+CaCl2}, {5SrBr2+8CaCl2} and {2ZnCl2 + CaCl2} were chosen for further evaluation. The multi-cycle TGA/DSC measurements of {2MgCl2+ KCl}, {2MgCl2+CaCl2} and {5SrBr2+8CaCl2} showed an improved cycle stability for all three materials over the untreated educts. Of the four materials {2ZnCl2 + CaCl2} displayed the strongest deliquescence during hydration in the upscaled experimental setup. {2MgCl2+CaCl2} proved to be the most stable material regarding the heat storage density. The {MgCl2} content of the mixture is likely to partially or completely react to {Mg(OH)Cl} at temperatures of T > 110°C, which however does not impede the heat storage density. {5SrBr2+8CaCl2} displayed a low melting point in hydrated state, causing a fast material loss. This makes it an undesirable storage material. A lower heating rate may still help to avoid an early melting. The {2MgCl2+KCl} mixture was the most temperature stable of the mixtures showing no melting or dissolving behavior. A reaction of the {MgCl2} component of the mixture to {Mg(OH)Cl} was not observed within the applied temperature range of T = 25 to 200°C.

Panic disorder is a common anxiety disorder, which is associated with high subjective burden as well as a high cost for the health economy. According to the National Treatment Guideline S3, cognitive behavior therapy is recommended as the most effective psychological treatment. However, many people in need do not have access to cognitive behavior therapy. Internet-based interventions have proven to be an effective way to provide access to evidence-based treatment to those affected, thereby reducing gaps in care. For anxiety disorders, such as panic disorder and agoraphobia, a good effectiveness of internet-based interventions has been proven in numerous international studies. However, the internet has changed over the last few years: mobile technologies have considerable potential to further improve the adherence and effectiveness of internet-based interventions. Against this background, we developed the hybrid online training

Durch die Neufassung des § 68f Abs.1 Satz 1 StGB tritt die Führungsaufsicht bei vollverbüßter Strafe von zwei Jahren oder bei schwerwiegenden Taten gemäß § 181b StGB nach einem Jahr kraft Gesetzes ein. Diese Reform im Jahr 2007 hat zu einem enormen Anstieg von Führungsaufsichten nach vollverbüßter Jugendstrafe geführt. Die Regelungen und Aufgaben der Verantwortlichen der Führungsaufsicht nach Jugendstrafe sind vielfältig und anders als beispielsweise bei der Führungsaufsicht nach einer Maßregel der Besserung und Sicherung (gem. §§ 63f). Für die Arbeit mit straffälligen Jugendlichen und Heranwachsenden unter Führungsaufsicht nach vollverbüßter Jugendstrafe gibt es für die Justizsozialarbeitenden keine explizite Handreichung. Im Vordergrund der Arbeit liegt die Frage: „Welche Faktoren können, aus Sicht der beteiligten Akteure, die Legalbewährung jugendlicher und heranwachsender Vollverbüßer unter Führungsaufsicht begünstigen?“ Die Praxisforschung wird, anhand von 15 Interviews mit den Verantwortlichen der Führungsaufsicht dargestellt und nimmt Bezug auf das in der Praxis erprobte Modellprojekt RESI und das Lebenslagenkonzept.

My dissertation embraces four empirical papers addressing socio-economic issues relevant to policy-makers and society as a whole. These papers cover important aspects of human life including health at birth, life satisfaction, unemployment periods and retirement decisions, and are intended to provide a contribution to the respective research areas. The analyses are carried out applying advanced econometric methods and are based on data sets consisting of survey data as well as administrative records. The joint paper with Alessandro Palma and Daniela Vuri "Prenatal Air Pollution Exposure and Neonatal Health" in Chapter 2 investigates the causal impact of prenatal exposure to air pollution on neonatal health in Italy in the 2000s combining detailed information on mother’s residential location from birth certificates with PM10 concentrations from air pollution monitors. Variation in local weekly rainfall is exploited as an instrumental variable for non-random air pollution exposure. Using quasi-experimental variation in rainfall shocks allows to identify the effect of PM10, ruling out potential bias due to confounder pollutants. The paper estimates the effect of exposure for both the entire pregnancy period and separately for each trimester to test whether the neonatal health effects are driven by pollution exposure during a particular gestation period. This information enhances our understanding of the mechanisms at work and help prevent pregnant mothers from most dangerous exposure periods. Additionally, the effects of prenatal exposure to PM10 are estimated by maternal labor market status and maternal education level to understand how the pollution burden is shared across different population groups. This decomposition allows to identify possible mechanisms through which environmental inequality reinforces the negative impact of early-life exposure to air pollution. This study finds that average PM10 and days with PM10 level above the hazard limit reduce birth weight, gestational age, and measures of overall newborn health. Effects are largest for third trimester exposure and for low-income and less educated mothers. These findings imply that further policy efforts are needed to fully protect fetuses from the adverse effects of air pollution and to mitigate the environmental inequality of health at birth. The joint paper with Christian Pfeifer "Life Satisfaction in Germany After Reunification: Additional Insights on the Pattern of Convergence" in Chapter 3 updates previous findings on the total East-West gap in overall life satisfaction and its trend by using data from the German Socio-Economic Panel for the years 1992 to 2013. Additionally, the effects are separately analyzed for men and women as well as for four birth cohorts. The results indicate that reported life satisfaction is, on average, significantly lower in East than in West German federal states and that part of the raw East-West gap is due to differences in household income and unemployment status. The conditional East-West gap decreased in the first years after the German reunification and remained quite stable and sizable since the mid-nineties. The results further indicate that gender differences are small. Finally, the East-West gap is significantly smaller and shows a trend towards convergence for younger birth cohorts. The joint paper with Christian Pfeifer "Unemployment Benefits Duration and Labor Market Outcomes: Evidence from a Natural Experiment in Germany" in Chapter 4 explores the effects 2 of a major reform of unemployment benefits in Germany on the labor market outcomes of individuals with some health impairment. The reform induced a substantial reduction in the potential duration of regular unemployment benefits for older workers. This work analyzes the reform in a wider framework of institutional interactions, which allows to distinguish between its intended and unintended effects. The results based on routine data collected by the German Statutory Pension Insurance and a Difference-in-Differences design provide causal evidence for a significant decrease in the number of days in unemployment benefits and increase in the number of days in employment. However, they also suggest a significant increase in the number of days in unemployment assistance, granted upon exhaustion of unemployment benefits. Transitions to unemployment assistance represent an unintended effect, limiting the success of a policy change that aims to increase labor supply via reductions in the generosity of the unemployment insurance system. The single-authored paper "How Older Workers Respond to Raised Early Retirement Age: Evidence from a Kink Design in Germany" in Chapter 5 explores how an increase in the early retirement age affects labor force participation of older workers. The analysis is based on a social security reform in Germany, which raised the early retirement age over several birth cohorts to boost employment of older people and ultimately alleviate the burden on the public pension system. Detailed administrative data from the Federal Employment Agency allow to distinguish between employment and unemployment as well as disability pensions and retirement benefits claims. Using a Regression Kink design in a quasi-experimental framework, I show that the raised early retirement age had positive employment effects and negative effects on retirement benefits claims. The reform did not affect unemployment benefits or disability pensions claims. My results also show that some population groups are more sensitive to a reduction in retirement options and more likely to seek benefits from other government programs. In this respect, I find that workers in manufacturing sector respond to the raised early retirement age by claiming benefits from the disability insurance program designed to compensate for reduced earnings capacity due to severe health problems. The treatment heterogeneity analysis further suggests that high-wage workers are more likely to delay exits from employment, which is in line with incentives but might also indicate an increased inequality within the affected birth cohorts induced by the reform. Finally, women seem to rely on alternative sources of income such as retirement benefits for women, or spouse's or partner's income not observed in the data. All things considered, workers did not adjust to the increased early retirement age by substituting early retirement with other government programs but rather responded to the reform in line with the policy intent. At the same time, the findings point to heterogeneous behavioral responses across different population groups. This implies that raising the early retirement age is an effective policy tool to increase employment only among older people who have the real choice to delay employment exits. Therefore, reforms that raise statutory ages should ensure social support for workers only marginally attached to the labor market or not able to work longer due to potential health problems or other circumstances.

The world currently faces important issues concerning climate change and environmental sustainability, with the wellbeing of billions of people around the world at risk over the next decades. Existing institutions no longer appear to be sufficiently capable to deal with the complexity and uncertainty associated with the wicked problem of sustainability. Achieving the required sustainability transformation will thus require purposeful reform of existing institutional frameworks. However, existing research on the governance of sustainability of sustainability transformations has strongly focused on innovation and the more ‘creative’ aspects of these processes, blinding our view to the fact that they go hand with the failure, decline or dismantling of institutions that are no longer considered functional or desirable. This doctoral dissertation thus seeks to better understand how institutional failure and decline can contribute productively to sustainability transformations and how such dynamics in institutional arrangements can serve to restructure existing institutional systems. A systematic review of the conceptual literature served to provide a concise synthesis of the research on ‘failure’ and ‘decline’ in the institutional literature, providing important first insights into their potentially productive functions. This was followed up by an archetype analysis of the productive functions of failure and decline, drawing on a wide range of literatures. This research identified five archetypical pathways: (1) crises triggering institutional adaptations toward sustainability, (2) systematic learning from failure and breakdown, (3) the purposeful destabilisation of unsustainable institutions, (4) making a virtue of inevitable decline, and (5) active and reflective decision making in the face of decline instead of leaving it to chance. Empirical case studies looking at the German energy transition and efforts to phase out coal in the Powering Past Coal Alliance served to provide more insights on (a) how to effectively harness ‘windows of opportunity’ for change, and (b) the governance mechanisms used by governments to actively remove institutions. Results indicate that the lock-in of existing technologies, regulations and practices can throw up important obstacles for sustainability transformations. The intentional or unintentional destabilisation of the status quo may thus be required to enable healthy renewal within a system. This process required active and reflective management to avoid the irreversible loss of desirable institutional elements. Instruments such as ‘sunset clauses’ and ‘experimental legislation’ may serve as important tools to learn through ‘trial and error’, whilst limiting the possible damage done by failure. Focusing on the subject of scale, this analysis finds that the level at which failure occurs is likely to determine the degree of change that can be achieved. Failures at the policy-level are most likely to merely lead to changes to the tools and instruments used by policy makers. This research thus suggests that failures on the polity- and political level may be required to achieve transformative changes to existing power structures, belief-systems and paradigms. Finally, this research briefly touches on the role of actor and agency in the governance of sustainabilitytransformations through failure and decline. It finds that actors may play an important role in causing a system or one of its elements to fail and in shaping the way events are come to be perceived. Drawing on the findings of this research, this dissertation suggests a number of lessons policy makers and others seeking to revisit existing institutional arrangements may want to take into account. Actors should be prepared to harness the potential associated with failure and decline, preserve those institutional elements considered important, and take care to manage the tension between the need for ‘quick fixes’ to currently pressing problems and solution that maintain and protect the longterm sustainability of a system.

Network analysis methods have long been used in the social sciences. About 25 years ago, these methods gained popularity in various other domains and many real-world phenomena have been modeled using networks. Well-known examples include (online) social networks, economic networks, web graphs, metabolic networks, infrastructure networks, and many more. Technological development made it possible to store and process data on a scale not imaginable decades ago — a development that also includes network data. A particular characteristic of network data is that, unlike standard data, the objects of interest, called nodes, have relationships to (possibly all) other objects in the network. Collecting empirical data is often complicated and cumbersome, hence, the observed data are typically incomplete and might also contain other types of errors. Because of the interdependent structure of network data, these errors have a severe impact on network analysis methods. This cumulative dissertation is about the impact of erroneous network data on centrality measures, which are methods to assess the position of an object, for example a person, with respect to all other objects in a network. Existing studies have shown that even small errors can substantially alter these positions. The impact of errors on centrality measures is typically quantified using a concept called robustness. The articles included in this dissertation contribute to a better understanding of the robustness of centrality measures in several aspects. It is argued why the robustness needs to be estimated and a new method is proposed. This method allows researchers to estimate the robustness of a centrality measure in a specific network and can be used as a basis for decision making. The relationship between network properties and the robustness of centrality measures is analyzed. Experimental and analytical approaches show that centrality measures are often more robust in networks with a larger average degree. The study of the impact of non-random errors on the robustness suggests that centrality measures are often more robust if missing nodes are more likely to belong to the same community compared to missingness completely at random. For the development of imputation procedures based on machine learning techniques, a process for the evaluation of node embedding methods is proposed.

Online behaviors analysis consists of extracting patterns from server-logs. The works presented here were carried out within the “mBook” project which aimed to develop indicators of the quantity and quality of the learning process of pupils from their usage of an eponymous electronic textbook for History. In this thesis, we investigate several models that adopt different points of view on the data. The studied methods are either well established in the field of pattern mining or transferred from other fields of machine learning and data-mining. We improve the performance of archetypal analysis in large dimensions and apply it to unveil correlations between visibility time of particular objects in the e-textbook and pupils’ motivation. We present next two models based on mixtures of Markov chains. The first extracts users’weekly browsing patterns. The second is designed to process essions at a fine resolution, which is sine qua non to reveal the significance of scrolling behaviors. We also propose a new paradigm for online behaviors analysis that interprets sessions as trajectories within the page-graph. In this respect, we establish a general framework for the study of similarity measures between spatio-temporal trajectories, for which the study of sessions is a particular case. Finally, we construct two centroid-based clustering methods using neural networks and thus lay the foundations for unsupervised behaviors analysis using neural networks. Keywords: online behaviors analysis, educational data mining, Markov models, archetypal analysis, spatio-temporal trajectories, neural network

Die vorliegende Simulationsstudie befasst sich mit der Etablierung und Veränderung der Personal-politik von Organisationen. Das den Simulationsrechnungen zugrunde liegende Modell beschreibt und erklärt den Einfluss personalpolitischer Kraftfelder auf die personalpolitischen Orientierungen von Organisationen. Berücksichtigt werden dabei die Rückwirkungen, die von der Personalpolitik auf die sie bestimmenden Kräfte ausgehen sowie die Beharrungskräfte, die einer einmal etablier-ten personalpolitischen Konstellation innewohnen. Und schließlich wird den Zufallsprozessen, die das personalpolitische Geschehen wesentlich mitbestimmen, die ihnen gebührende Beachtung ge-schenkt. Als theoretische Grundlage dient eine erweiterte und auf die Erklärung der Personalpolitik hin aus-gerichtete Version der Anreiz-Beitrags-Theorie, wonach sich, je nach den gegebenen Feldkraft-konstellationen, angepasste Sozialordnungen herausbilden. Die Elemente und Strukturen dieser Sozialordnungen sind aufeinander abgestimmt und stützen sich gegenseitig. Daraus entwickeln sich interne „Bindungskräfte“, die den verschiedenen Sozialordnungen ihre je eigene Stabilität ver-leihen. Die in dieser Theorie thematisierten Zusammenhänge werden in dem Simulationsmodell konkretisiert und in entsprechende Rechenvorschriften transformiert. Damit wird es möglich, den Ablauf und die Wirkung der von der Theorie unterstellten Mechanismen anhand von konkret be-nennbaren Vorgängen zu analysieren.

Empirische Studien aus dem Bereich der Lehrerbildungsforschung haben gezeigt, dass die Arbeit mit Unterrichtsvideos eine wirksame Möglichkeit darstellt, um professionelle Kompetenzen von Lehramtsstudierenden zu erweitern. In der Unterrichtsforschung werden Unterrichtsvideos darüber hinaus auch als Messinstrument zur Wahrnehmung von Unterrichtsqualität genutzt. Dabei werden meist Filmaufnahmen verwendet, die mit einer Überblicks- oder Lehrerkamera gefilmt wurden. In diesem Kontext äußern Bildungswissenschaftlerinnen und Bildungswissenschaftler die Annahme, dass die gefilmte Kameraperspektive einen Effekt auf die Beobachtung und Beurteilung der Unterrichtsvideos haben kann. Empirische Befunde sind zu dieser Hypothese bisher wenig vorhanden. Die vorliegende Dissertation hat sich daher - in der Tradition standardisierter Videostudien - das Ziel gesetzt, das bisherige standardisierte Kamerasetting inhaltlich-konzeptionell durch die Installierung mehrerer Schülerkameraperspektiven weiterzuentwickeln. Auf dieser Grundlage wurde geprüft, ob die Raterinnen und Rater durch den Einsatz multiperspektivischer Videos in ihrer Einschätzung der Unterrichtsqualität zu unterschiedlichen Ergebnissen gelangen. Die Befunde belegen, dass Raterinnen und Rater ein Unterrichtsgeschehen mit den etablierten Perspektiven der Überblicks- oder Lehrerkamera nahezu ähnlich einschätzen. Mit weiteren Kameraperspektiven, die auf die Schülerinnen und Schüler gerichtet sind, wird jedoch eine deutlich breitere Beurteilung in den Dimensionen „Kognitive Aktivierung“, „Klassenmanagement“ und „Individuelle Förderung“ deutlich. Mehrere Kameraperspektiven ermöglichen detaillierte Aussagen über Unterricht - von diesem Ergebnis können auch Studierende in der Lehrpersonenausbildung profitieren. Schülerkameraperspektiven eröffnen Dozierenden insbesondere zur Thematik „heterogene Schülerschaft“ ein didaktisches Lehrmittel und Werkzeug, das eine Videoanalyse zu Mikrointeraktionen zwischen Schülerinnen und Schülern-Lehrpersonen-Interaktionen dynamisch und simultan erlaubt. Die befragten Studierenden dieser Arbeit gaben an, gern in weiteren Lehrveranstaltungen mit mehrperspektivischen Unterrichtsvideos zu arbeiten.

Mobilität und Tourismus gehören untrennbar zusammen, denn ohne einen Ortswechsel gibt es keine Urlaubsreise. Der Tourismus aber verursacht ca. 5 % der anthropogenen Kohlendioxidemissionen, von denen etwa 75% auf den touristischen Verkehr entfallen. Neben dem Flugverkehr trägt insbesondere der motorisierte Individualverkehr einen hohen Anteil an den Emissionen. Angesichts des deutlichen Beitrags des touristischen Verkehrs zum Klimawandel erscheint es notwendig, sich mit Wegen zu einer ökologischen touristischen Mobilität zu beschäftigen. Zur Untersuchung der Einflussfaktoren auf die touristische Verkehrsmittelwahl wurde ein Erklärungsmodell basierend auf der Theorie des geplanten Verhaltens entwickelt. Neben den Basiskonstrukten der Einstellung, der subjektiven Norm und der wahrgenommenen Verhaltenskontrolle wurden als ergänzende Modellkonstrukte die persönliche Norm, das allgemeine Umweltbewusstsein sowie gewohnheitsmäßiges Handeln hinzugefügt. Eine empirische Untersuchung mit n=738 ermittelte durch multiple lineare Regression wichtige Ansatzpunkte für die Gestaltung von Handlungsempfehlungen. Signifikante Ergebnisse konnten für die Konstrukte der Einstellung, der subjektiven Norm, der wahrgenommenen Verhaltenskontrolle, der persönlichen Norm, der Gewohnheit sowie der Kontrollvariablen Alter und Einkommen erreicht werden. An diesen Einflussfaktoren auf die Intention, zukünftig ein umweltfreundlicheres Verkehrsmittel zur Reise in den nächsten Städte-Kurzurlaub zu wählen, setzen die Implikationen für die Praxis an und zeigen Möglichkeiten auf, die touristische Mobilität ökologischer zu gestalten.

Der vorliegende Beitrag befasst sich mit Typisierungen der Personalpolitik, die sich darauf rich-ten, charakteristische Muster der Personalpolitik zu identifizieren und deren Zustandekom-men zu erklären. Beschrieben werden der Erkenntniswert, der typologischen Ansätzen zu-kommt, und die Schwierigkeiten, die sich der Identifikation personalpolitischer Muster entge-genstellen. Ungeachtet der sich dabei stellenden Probleme erscheint es wünschenswert und möglich, über lediglich intuitiv plausible Ansätze hinauszugehen und theoretisch gut veran-kerte Typologien zu entwickeln. Einen breiten Raum nimmt im vorliegenden Beitrag die Darstellung der in der Literatur vor-findlichen Typisierungen der Personalpolitik ein. Zu unterscheiden ist hierbei zwischen Typo-logien, die sich auf das Gesamtsystem Organisation und Typologien, die sich, im engeren Sinne, auf einzelne Funktionsbereiche des Personalwesens beziehen. Das Spektrum der den Typisierungen zugrundeliegenden theoretischen Überlegungen erweist sich zwar als sehr breit, es wird aber dennoch von einigen wenigen Grundthemen bestimmt. Auch schließen sich die Typisierungen nicht gegenseitig aus, sie beleuchten oft einfach unterschiedliche Aspekte der Personalpolitik. Der Gedanke, dass sich verschiedenartige personalpolitische Ausrichtun-gen ergänzen und in ihrer Wirkung verstärken können, wird im Konzept der „Sozio-Bricks“ aufgenommen und vertieft. Hierauf wird gesondert eingegangen. Danach werden die Erfahrungen aus einer Reihe von empirischen Erkundungen beschrieben, die darauf abzielten, das komplexe Untersuchungsobjekt Personalpolitik näher zu charakteri-sieren und anschaulich zu machen. Als theoretische Referenz diente das Sozio-Bricks-Konzept und es wurde geprüft, ob sich mit dessen Hilfe stimmige, in der betrieblichen Realität vorfind-liche, personalpolitische Muster identifizieren lassen. Abschließend wird mit der Simulationsmethode noch ein Ansatz theoretischer Erkundungsar-beit skizziert. Der große Vorteil von Simulationsmodellen besteht darin, dass sie dazu zwingen, die Mechanismen zu operationalisieren, die man dafür verantwortlich macht, dass sich be-stimmte personalpolitische Muster herausbilden. Außerdem erlauben entsprechend konzi-pierte Modelle, den Wirkungsverbund der auf die Personalpolitik einwirkenden Kräfte zu un-tersuchen.

The currently widespread agricultural practices have been increasingly criticised in recent years. They are especially criticised for being unsustainable on an ecological, economic and social level (compare Kalfagianni & Skordili, 2019). Recent developments in the global food system lead to a lack of transparency and unethical practices with negative impacts on human health and the environment from the consumer’s perspective (Wellner & Theuvsen, 2017, p. 235) and to pressure of modernisation and intensification processes from the producer’s perspective. This results in fear for farmers’ existences (Boddenberg et al., 2017, p. 126) and leads to an increased vulnerability of the current food system (Kalfagianni & Skordili, 2019, pp. 3–4). It endangers long-term reliable food provisions and therefore calls for a change of supply and production practices.

Neither market income nor consumption expenditure provides an adequate picture of individual standard of living. It is time which enables and restricts individual activities and is a further brick to a more comprehensive picture of individual wellbeing. In our study we focus on a prominent part of time use in non-market services: it is parental child care which contributes not only to individual but also to societal well-being. Within a novel approach we ask for multidimensional polarization effects of parental child care where compensation/ substitution of time for parental child care versus income is interdependently evaluated by panel estimates of societys subjective well-being. The new interdependent 2DGAP measure thereby provides multidimensional polarization intensity information for the poor and the rich and disentangles the single time and income contribution to subjective well-being ensuring at the same time the interdependence of the polarization dimensions. Socio-economic influences on the polarization pole risk and intensity will be quantified by two stage Heckman estimates. The analyses are based on the German Socio-Economic Panel with 21 waves and robust fixed effects estimates of subjective well-being as well as the German Time Use Surveys 1991/92 and actual 2012/13 with detailed diary time use data. The empirical results discover the interdependent relations between parental child care and income under a common evaluation frame and contribute to the question of dimension specific targeted policies in a multidimensional polarization approach. Prominent result: compensation between parental child care time and income proved to be significant, but there are multidimensional regions with no compensation, where parental child care time deficit is not compensated by income. Interdependent multidimensional polarization by headcount and intensity increased significantly over the twenty years under investigation with remarkable risk and intensity differences between the polarization poles with different disentangled parental child care time and income contributions to subjective well-being.

The image of the solitary scientist is receding. Increasingly, researchers are expected to work in collaborative interdisciplinary teams to tackle more complex and interrelated problems. However, the prospect of collaborating with others, from different disciplines, exerts countervailing forces on researchers. There is the lure of transcending the limitations of one’s own knowledge, methods and conventions, belonging to diverse intellectual communities and tackling, together, ambitious research topics. On the other hand, there is the risk that collaborating across disciplinary boundaries will be taxing, confounding at times, with no guarantee of success. In short, interdisciplinary collaboration is both a desirable and difficult way to conduct research. This thesis is about collaborative interdisciplinary research from the perspective of a formative accompanying researcher. I accompanied an interdisciplinary research team in the field of sustainability over three years for the duration of a collaborative project. Formative accompanying research (FAR) is an approach to ‘research into research’ that learns about, with and for a collaborative interdisciplinary team. I found – through immersion in the literature, my own daily experiences of collaborating, and my observations – that interdisciplinary collaboration is very difficult. It requires a basic understanding and appreciation of other disciplines and methods, as well as the skills to integrate research inquiries and findings across diverse epistemologies. It also requires awareness that collaborative interdisciplinary research is more than an intellectual task of knowledge creation. Other factors matter, such as interpersonal relationships, power differentials, different research tempos and a sense of belonging. And these factors have an impact on processes and outcomes of collaborative knowledge creation. Knowing this implies a willingness to keep learning and to tolerate discomfort so as to cultivate deeper levels of collaborative capacity. I discovered that in these deeper levels lie skills for staying with inevitable tensions, for talking and listening to generate new understanding together, and for applying a researcher’s frank curiosity to oneself too. A formative accompanying researcher, who is part of the team she is researching, has to navigate delicate terrain. In this thesis, I develop a FAR methodology that takes seriously the questions of positionality and relationality, and reflect on the experiences of putting these into practice. A FAR practice involves remaining in dynamic movement between observing and participating, between exercising curiosity and care, and between the researchers’ own sense of impartiality and investment in relation to the issues at hand. There is merit in furthering the methodology and practice of FAR on its own terms. This includes attending to the skills required by a formative accompanying researcher to remain oriented within the concentric circles of research, relationship and loyalty that make up a collaborative team. There is also the question of how FAR, and other forms of research into research, can help to advance collaborative interdisciplinary research. I argue for creating the conditions in research teams that would enable treating collaboration as a capacity to develop, and that would facilitate team members’ receptivity to learning with FAR. Furthermore, I explore dilemmas of intervening as a formative accompanying researcher and of sustaining dynamic positionality over the long-term. In the field of sustainability research, and in multiple other research fields, the future is a collaborative one. This thesis is concerned with how to collaborate so that the experience and the outcomes lend themselves to what Rabinow terms a “flourishing existence”.

Vielen Menschen fällt es schwer, regelmäßig sportlich aktiv zu sein (Duttler, 2014). Diese Problematik ist bereits im Jugendalter zu beobachten und zeigt sich darin, dass viele Jugendliche nicht ausreichend körperlich aktiv sind (HBSC-Studienverbund Deutschland, 2015). Sportliche Inaktivität und Bewegungsmangel wirken sich sowohl negativ auf die Gesundheit als auch auf die gesamte psychische und physische Entwicklung eines Menschen aus (Hair, Park, Ling & Moore, 2009). Einer der wichtigsten Faktoren für eine langfristige und kontinuierliche sportliche Betätigung ist das Erleben von Freude während des Sports (Woods, Tannehill & Walsh, 2012). Freude am Sport sollte möglichst frühzeitig, beispielsweise im Schulsport, gefördert werden, da hier eine große Anzahl Jugendlicher erreicht werden kann. Diese Dissertation beschäftigt sich mit der zentralen Frage, auf welche Art und Weise Freude an sportlicher Aktivität im Rahmen des Schulsports gefördert werden kann, so dass Jugendliche animiert werden auch außerhalb der Schule regelmäßig sportlich aktiv zu sein. Insgesamt wurden vier Studien durchgeführt um diese Fragestellung zu beantworten. In der ersten Studie wurde ein Fragebogen entwickelt und validiert, um Freude am Schulsport im Jugendalter messen zu können. Basierend auf theoretischen Ansätzen fand eine Weiterentwicklung des Konstrukts „Sportfreude“ zu einem 3-Faktorenmodell (Vergnügen, Flow-Erleben, Erholung) statt. Die psychometrische Untersuchung erfolgte anhand einer Stichprobe mit N = 1 253 Schülerinnen und Schülern der Klassenstufen 7 bis 10. Konfirmatorische Faktorenanalysen bestätigten die angenommene 3-Faktorenstruktur. Die Reliabilitätskoeffizienten der internen Konsistenz und der Retestung lagen im akzeptablen bis guten Bereich. Als Hinweise für die konvergente Validität liegen Korrelationen mit intrinsischer Motivation, allgemeiner Sportlichkeit, Sportnoten und dem Sportpensum in der Freizeit vor. Die zweite Studie zielte darauf ab, den in Studie I entwickelten Fragebogen zur Erfassung der Freude von Schülerinnen und Schülern im Schulsport hinsichtlich der Messinvarianz über verschiedene Schulformen zu überprüfen. Hierbei wurde untersucht, inwiefern die Messeigenschaften des Fragebogens für Schülerinnen und Schüler unterschiedlicher Schulformen (Gymnasium, Realschule, Hauptschule, Gesamtschule/Oberschule) vergleichbar sind. Darüber hinaus wurden Zusammenhänge der Freude (Vergnügen, Flow-Erleben, Erholung) am Schulsport mit den Sportnoten untersucht und über die unterschiedlichen Schulformen hinweg verglichen. Basierend auf einer Stichprobe von N = 1 351 Schülerinnen und Schülern wurden Nachweise für strikte Messinvarianz über Schulformen gefunden. Die drei Facetten der Freude korrelierten am höchsten mit den Sportnoten für Schülerinnen und Schüler der Hauptschule und am niedrigsten für die Schülerinnen und Schüler des Gymnasiums. Ziel der dritten Studie war es, den Einfluss von sieben Faktoren (wahrgenommene Kompetenz, soziale Eingebundenheit, sozialer Umgang, Autonomie/Mitbestimmung, Lehrkompetenz, allgemeine Sportlichkeit und elterliche Unterstützung) auf das Erleben von Freude am Schulsport zu untersuchen. Diese Faktoren wurden basierend auf der Selbstbestimmungstheorie (SDT; Deci & Ryan, 1985) und auf empirischen Befunden als besonders relevant für Freude erachtet. Diese Studie wurde mit N = 1 598 Schülerinnen und Schüler der Klassenstufen 7 bis 10 durchgeführt. Sportfreude wurde anhand des in Studie I validierten Fragebogens erfasst. Die Ergebnisse zeigten moderate bis starke Zusammenhänge von Freude mit den sieben Einflussfaktoren, wobei soziale Eingebundenheit und wahrgenommenes Kompetenzerleben sich als stärkste Prädiktoren erwiesen. In der vierten Studie wurde basierend auf den Erkenntnissen der vorherigen Studien ein Interventionsprogramm für den Schulsport entwickelt und evaluiert. Das Ziel war hierbei zu untersuchen, ob der Einsatz kooperativer Spiele zum einen das Erleben von Freude bei Schülerinnen und Schülern steigert und zum anderen zu einem stärkeren Gefühl von sozialer Eingebundenheit und wahrgenommener Kompetenz führt. Zur Untersuchung wurde ein Zwei-Gruppen Design mit Messwiederholung mit N = 285 Schülerinnen und Schülern verwendet. Hierfür wurde die Freude am Schulsport sowohl vor Beginn der Intervention als auch nach deren Beendigung untersucht. Die Ergebnisse zeigten sowohl einen direkten Effekt kooperativer Spiele auf das Erleben von Freude als auch einen indirekten Effekt, der über das Gefühl sozialer Eingebundenheit und wahrgenommenes Kompetenzerleben im Schulsport vermittelt wird. Der systematische Einsatz von kooperativen Spielen im Schulsport bietet somit eine Möglichkeit bei Jugendlichen positives Sporterleben zu fördern. Auf diese Weise kann Schulsport Jugendliche anregen auch außerhalb der Schule sportlich aktiv zu sein und bei der Entwicklung eines aktiven Lebensstils unterstützen.

We are in a phase of an alarming biodiversity loss, by scientist already referred to as Earth’s sixth mass extinction. According to estimations, the current extinction rates are 100 to 1000 times higher than those predicted from fossil records. To counteract species loss and preserve the remaining biodiversity, with its important ecosystem functioning and services essential to human well-being, there is an urgent need to develop promising and long-term conservation strategies. In order to achieve these goals, extensive research to gain a better understanding of the general mechanisms underlying community diversity is of greatest importance. Especially, the identification of intrinsic ecological and distributional species traits is receiving increased attention in ecology and conservation biology research. Depending on the expression of their traits, species perform particular ecosystem functions and respond in a specific manner to environmental conditions. The identification of the effect of certain traits on community compositions can therefore significantly improve our understanding of species extinction processes and help to develop valuable and appropriate recommendations for conservation management. As trait-based analyses are applicable to different geographical, temporal and taxonomical scales, they may even allow for a broader generalization if similar results are found on different scales, i.e. for local species pools, the complete species pools of different habitat types or the entire species pool across several habitat types including different climatic regions. Although insects make up the largest part of animal diversity and provide essential ecosystem services in form of e.g. pollination, pest control, and decomposition, the majority of studies on extinctions have mainly focused on vertebrates. Among invertebrates either charismatic taxa or those targeted by conservation laws have been investigated until now (e.g. butterflies or saproxylic beetles). Being highly species-rich and trait-diverse, ground beetles (Coleoptera: Carabidae) should be even more suitable for conducting trait-based analyses. Thus, using ground beetles as a model taxon, four case studies focusing on the analyses of traits form the basis of this doctoral thesis. The work of this thesis was conducted with the aim of gaining general insights on the influence of species traits on ground beetle community compositions, such as habitat occupancy and species vulnerability to extinction, for instance. An important aspect when investigating species traits is the consideration of confounding factors which could influence the results, such as dependent relations between the different traits. Compiling a large dataset of 566 Central European species, I identified that dependent relations between the six tested traits of ground beetles (distribution range size, habitat specialization, body size, hind-wing morphology, breeding season and trophic level) are highly common. Across all identified dependent trait relations, the relation between body size and hind wing morphology or range size and hind wing morphology showed the strongest significant dependencies. Since the consideration of trait relations is necessary to provide reliable interpretations, all analyses of this thesis tested several traits simultaneously and considered possible trait interactions. Studies on local communities found specific traits characterizing the local species pools of certain habitat types. Here, the species pools of seven different habitat types (coastal, forest, mountain, open, riparian, wetland and special habitat) were used to determine habitat-specific trait filters. The identified traits, characteristic for certain habitat types, were in most cases in accordance with the previous findings on local communities. Across Germany, the species of frequently disturbed habitat types, namely coastal, riparian and wetland habitats were characterized by small body size, high amount of macroptery, intermediate to high habitat specialization, spring breeding, and predatory feeding behavior. The species of stable habitat types (forest, mountain, and open habitats), however, were found to be generally larger in body size and more frequently breeding in autumn, further displaying greater variations in the other traits. The gained knowledge on the habitat-specific filtering of traits improve our understanding of the organization and assembly of communities, and can thereby help to detect alterations in the habitat-specific species pool due to natural or human-induced environmental changes. Furthermore, traits can provide evidence on species occurrences and vulnerability to extinction. Three case studies of this thesis aimed to gain new insights on this topic, through the investigations on the following research questions; I. Which traits drive species extinction risks of Central European ground beetle species, II. How traits influence the species occurrences of 28 forest species within a large area in Central Europe, and III. Whether certain traits are related to long-term population trends of the species pool from an ancient forest in northern Germany. The results indicated, that depending on the habitat type and tested species pool, different traits prove to be good predictors for the vulnerability of species. Nevertheless, across different geographical and taxonomical scales, especially species with small range sizes and high habitat specialization faced a greater risk of extinction. Therefore, the two traits distributional range size and habitat specialization emerge as reliable predictors of ground beetles vulnerability to extinction. Interestingly, body size did not display a consistent response; while increasing body size led to higher extinction risk in riparian, wetland and open habitats and large macropterous species showed higher extinction risks across the entire species pool, smaller species showed long-term population declines in an ancient forest. To summarize, this thesis presents a comprehensive picture of ground beetle species traits, providing valuable insights and a better understanding of the mechanisms driving changes in ground beetle diversity. On the basis of the results presented in this work, the efficiency of biodiversity protection can be increased by developing appropriate management and recovery plans, especially targeting species of threatened habitat types or ‘functional groups’ of species, exhibiting trait values strongly associated with a greater vulnerability to extinction.

Der Wandel des Energiesystems ist eine der zentralen Nachhaltigkeitstransformationen, denen sich die Forschung widmet. Wie für die Transition-Forschung verschiedenlich festgestellt, besteht allerdings eine gewisse Lücke bei der Frage, wie Nachhaltigkeitstransformationen organisiert und finanziert werden. Insbesondere fehlt es erstens an einer Ausdifferenzierung und vertieften Analyse einzelner institutionell-organisatorischer Lösungen und zweitens an einer Darstellung im Zusammenhang der komplexen sozio-ökologisch-technischen Systeme, in die konkrete Organisationslösungen für eine nachhaltige Energieversorgung eingebunden sind. In der vorliegenden Arbeit werden mit genossenschaftlichen Ansätzen, also Organisationslösungen mit (Teil-)Eigentum der Bürgerinnen und Bürger an den Anlagen, spezifische hybride finanzielle Arrangements im Energiesektor in den Fokus gerückt. Dem institutionenanalytischen Ansatz der Bloomington School folgend wird im Rahmenpapier und insgesamt sechs Fachartikeln der Frage nachgegangen, welche Formen genossenschaftlicher Ansätze im Global Norden und Globalen Süden anzutreffen sind und welche Rolle diesen in den Transformationsprozessen des jeweiligen Energiesystems zukommt. Für die Analyse wird auf das Social-Ecological Systems Framework zurückgegriffen, das für die einzelnen Untersuchungen modifiziert bzw. konkretisiert wird. Im Einzelnen wird in den Fachartikeln ein Überblick über die Erkenntnisse zu genossenschaftlichen Ansätzen im Globalen Süden gegeben, auf der Makroebene den wechselnden politischen Prozessen von Koordination und contestation nachgegangen, auf der Mesoebene die Entwicklungen von Windenergiegenossenschaften in Belgien, Dänemark, Deutschland und dem Vereinigten Königreich vergleichend analysiert, der Zusammenhang von Finanz- und Energiesystem untersucht und für diesen Kontext Gerechtigkeitsnormen konkretisiert und schließlich auf der Mikroebene die Inklusivität von Bürgerenergieinitiativen näher betrachtet und Unterschiede in den Investitionsmotiven verschiedener Bürgerenergieakteure herausgearbeitet.

Ensuring food security and halting biodiversity loss are two of the most pressing global sustainability challenges. Traditionally food security and biodiversity conservation were treated as mutually exclusive goals, and as a result, discourses and approaches were developed separately around each of these goals. Recently, however, sustainability science increasingly recognizes the close interdependence of food security and biodiversity and hence, pays greater emphasis to the need for integration of the two goals. Navigating pathways to ensure the successful integration of the two goals is, therefore, an important requirement. Attempts to identify pathways toward such integration have been dominated with a biophysical-technical focus that provides technical solutions to the integration of food security and biodiversity conservation. To this end, different food production techniques, and agricultural land use strategies have been widely considered as a solution to the food security-biodiversity nexus. While much scholarly attention has been given to the biophysical-technical dimensions, the social-political dimension, including equity, governance, and empowerment received little to no attention. By focusing on the poorly investigated social-political dimension, this dissertation aimed to identify governance properties that facilitate and impede the integration of food security and biodiversity conservation through an empirical case study conducted in a multi-level governance setting of southwestern Ethiopia. To address the overarching goal of this dissertation, first I examined how the existing widely discussed food security approaches and agricultural land use framework, land sparing versus land sharing unfold in the local context of southwestern Ethiopia. The finding in this dissertation indicated that the existing global framing of food security approaches as well as frameworks around agricultural land use has limited applicability in on-the-ground realities mainly because landscapes are complex systems that consist of stakeholders with multiple and (often) conflicting interests. This was evident from the finding that, unlike the binary framing of agricultural land use as land sparing and land sharing, local land use preference was not a matter of ‘either/or’, but instead involved mixed features exhibiting properties of both land sparing and land sharing. Moreover, in addition to the biophysical factors embedded in the existing food security approaches and land use frameworks, stakeholders preference involved social factors such as the compatibility of land use strategy with local values and traditions, which are mainly unaccounted in the existing global frameworks. Findings in his dissertation revealed that the existing reductionist analytical framings to the issues of food security and biodiversity conservation seldom address the complexity inherent within and between food security and biodiversity conservation sectors. Second, this dissertation identified governance structural and process related challenges that influence individual as well as integrated achievements of food security and biodiversity conservation goals. The result of the study showed that the governance of food security and biodiversity conservation was characterized by a strongly hierarchical system with mainly linear vertical linkages, lacking horizontal linkages between stakeholders that would transcend administrative boundaries. This type of governance structure, where stakeholders interaction is restricted to administrative boundaries could not fit with the nature of food security and biodiversity conservation because the two goals are complex in their own involving sub-systems transcending different policy sectors and administrative boundaries. Furthermore, with regard to the governance process, three key and interdependent categories of governance process challenges namely, institutional misfit, the problem of interplay, and policy incoherence influenced the achievement of individual and integrated goals of food security and were identified. Given the interdependence of these governance challenges, coupled with the complexity inherent in the food security and biodiversity conservation, attempts to achieve the dual goals thus needs an integrative, flexible and adaptive governance system Third, to understand how food security and biodiversity conservation unfold in the future, I explored future development trajectories for southwestern Ethiopia. Iterative scenario planning process produced four plausible future scenarios that distinctly differed with regard to dominating land use strategies and crops grown, actor constellations and governance mechanisms, and outcomes for food security and biodiversity conservation. Three out of the four scenarios focused on increasing economic gains through intensive and commercial agricultural production. The agricultural intensification and commercialization may increase food availability and income gains, but negatively affect food security through neglecting other dimensions such as dietary diversity, social justice and stability of supply. It also affects biodiversity conservation by causing habitat loss, land degradation, and water pollution, biodiversity loss. In contrast, one scenario involved features that are widely considered as beneficial to food security and biodiversity conservation, such as agroecological production, diversification practices, and increased social-ecological resilience. In smallholder landscapes such as the one studied here, such a pathway that promises benefits for both food security and biodiversity conservation may need to be given greater emphasis. In order to ensure the integration of food security and biodiversity conservation, recognizing their interdependence and addressing the challenges in a way that fits with the local dynamics is essential. In addition, addressing the food security-biodiversity nexus requires a holistic analytical lens that enables proper identification of system properties that benefit food security and biodiversity conservation. Moreover, this dissertation indicated that there is a clear need to pay attention to the governance structure that accommodates the diversity of perspectives, enable participation and strong coordination across geographical boundaries, policy domains and governance levels. Finally, this dissertation revealed opportunities to integrate food security and biodiversity through the pro-active management of social-ecological interactions that produce a win-win outcome. The win-win outcome could be achieved in a system that involve properties such as diversification and modern agroecological techniques, smallholders empowerment, emphasize adaptive governance of social-ecological systems, value local knowledge, culture and traditions, and ensure smallholders participation. While such diversification and agroecological practices may lack the rapid economic development that is inherent to the conventional intensification, it essentially create a system that is more resilient to environmental and economic shocks, thereby providing a more sustainable long-term benefit.

This cumulative thesis extends the econometric literature on testing for cointegration in nonstationary panel data with cross-sectional dependence. Its self-contained chapters consist of two publications and two publication manuscripts which present three new panel tests for the cointegrating rank and an empirical study of the exchange rate pass-through to import prices in Europe. The first chapter introduces a new cointegrating rank test for panel data where the dependence is assumed to be driven by unobserved common factors. The common factors are first estimated and subtracted from the observations. Then an existing likelihood-ratio panel cointegration test is applied to the defactored data. The distribution of the test statistic, computed from defactored data, is shown to be asymptotically equivalent to that of a test statistic computed from cross-sectionally independent data. The second chapter proposes a new panel cointegrating rank test based on a multiple testing procedure, which is robust to positive dependence between the individual units’ test statistics. The assumption of a certain type of positive dependence is shown by simulations not to be violated in panels with dependence structures commonly assumed in practice. The new test is applied to find empirical support of the monetary exchange rate model in a panel of eight OECD countries. The third chapter puts forward a new panel cointegration test allowing for both cross-sectional dependence and structural breaks. It employs known individual likelihood-ratio test statistics accounting for breaks in the deterministic trend and combines their p-values by a novel modification of the Inverse Normal method. The average correlation between the probits is inferred from the average cross-sectional correlation between the residuals of the individual VAR models in first differences. The fourth chapter studies the exchange rate pass-through to import prices in a panel of nineteen European countries through the prism of panel cointegration. Empirical evidence supporting a theoretical long-run equilibrium relationship between the model’s variables is found by the newly proposed panel cointegration tests. Two different panel regression models, which take both cointegration and cross-sectional dependence into account, provide most recent estimates of the exchange rate pass-through elasticities.

Global climate change and environmental degradation are largely caused by human activity, thus progress towards a sustainable future will require large-scale changes to human behavior. Human-nature connectedness—a measure of cognitive, emotional, spiritual and biophysical linkages to natural places—has been identified as a positive predictor of sustainability attitudes and behaviors. While calls to ‘reconnect to nature’ in order to foster sustainability outcomes have become common across science, policy and practice, there remains a great deal of uncertainty, speculation, and conceptual vagueness around how this ought to be implemented. The overarching aim of this thesis is to advance conceptual and empirical understandings of human-nature connectedness as a leverage point for proenvironmental outcomes and sustainability transformation. In particular, the thesis attempts to assess the nuances of the HNC-PEB relationship by investigating the scalar relationships between where someone feels connected to nature and where someone acts proenvironmentally. This research was conducted through conceptual exploration (Chapters II, III, IV, and VI), systematic literature reviews (Chapter I and V) using hierarchical cluster analysis, and empirical case studies (Chapters VII and VIII) relying on structural equation modeling and two-step cluster analysis. In this thesis, the relationship between humannature connectedness and pro-environmental attitudes and behaviors was investigated in a small microregion of Transylvania, Romania, where traditional relationships with the land and changing socio-economic characteristics provided an interesting case study in which to explore these connections. The key findings can be organized into three sections: Section A, which addresses human-nature connectedness and its potential for sustainability transformation; Section B, which addresses human-nature connectedness as a determinant of pro-environmental behavioral outcomes, and Section C, which explores the relationships between human-nature connectedness and energy conservation norms, attitudes, and behaviors. Results cumulatively suggest that human-nature connectedness is a multidimensional construct that requires greater integration across heterogeneous disciplinary and methodological boundaries in order to reach its potential for meaningful sustainability transformation. Results also highlight the critical need to adopt systemic approaches to understanding how interactions between human-nature connections, norms, attitudes, and behaviors are hindering or promoting sustainability outcomes. This thesis makes two main contributions to the literature: first, it considers the human-nature connectedness and pro-environmental behavior literature within a systems-thinking and VI sustainability transformation lens; and second, it extends the human-nature connectedness and pro-environmental behavior literature by investigating the multidimensional aspects of these constructs. Overall, these insights point to the deep leverage potential of humannature connectedness when conceptualized and operationalized as a multidimensional construct.

This cumulative dissertation deals with the association between corporate governance, corporate finance and corporate tax avoidance in four scientific articles. The aim of this dissertation is to explain corporate tax avoidance by (a) focusing on corporate governance institutions as determinants of tax avoidance and (b) focusing on financial consequences of tax avoidance. Due to the close association between corporate governance and the concept of corporate social responsibility (CSR), the relationship between CSR and tax avoidance is also addressed. The first article with the title „The impact of corporate governance on corporate tax avoidance – A literature review“, using structured literature review methodology, analyzes extant research on the association between corporate governance and tax avoidance based on stakeholder-agency theory. However, also classical principal-agent theory is taken into account as its classical foundation. The first article identifies a number of open research questions and thereby serves as a theoretical basis for the subsequent articles. The second article with the title „CSR and tax avoidance: A review of empirical research“, also using structured literature review methodology, analyzes extant research on the association between CSR and tax avoidance. This article is also based on stakeholder-agency theory and identifies open research questions. The third article with the title „Tax Avoidance in Family Firms: Evidence from Large Private Firms“, based on results of the first article, investigates tax avoidance by German private family firms as a specific variant of corporate governance, using an empirical quantitative approach. The article finds that (a) German private family firms avoid more tax than non-family firms, that (b) tax avoidance is positively associated with the capital stake of the family and that (c) tax avoidance is positively associated with the number of shareholders in both family and non-family firms. Results reinforce that corporate tax avoidance is associated to conflicts among the shareholders of private firms. The fourth article with the title „Tax avoidance, tax risk and the cost of debt in a bank-dominated economy“ investigates the cost of debt of German public firms as a function of tax avoidance and tax risk. The article finds that (a) tax avoidance is negatively associated to the cost of debt, that (b) tax risk is positively associated to the cost of debt and that (c) the association between tax avoidance and the cost of debt becomes negative when a high level of tax risk is present.

Climate change and atmospheric deposition of nitrogen affect biodiversity patterns and functions of forest ecosystems worldwide. Many studies have quantified tree growth responses to single global change drivers, but less is known about the interaction effects of these drivers at the plant and ecosystem level. In the present study, we conducted a full-factorial greenhouse experiment to analyse single and combined effects of nitrogen fertilization (N treatment) and drought (D treatment) on 16 morphological and chemical response variables (including tissue δ13C signatures) of one-year-old Fagus sylvatica seedlings originating from eight different seed families from the Cantabrian Mountains (NW Spain). Drought exerted the strongest effect on response variables, reflected by decreasing biomass production and increasing tissue δ13C signatures. However, D and N treatments interacted for some of the response variables, indicating that N fertilization has the potential to strengthen the negative effects of drought (with both antagonistic and amplifying interactions). For example, combined effects of N and D treatments caused a sevenfold increase of necrotic leaf biomass. We hypothesize that increasing drought sensitivity was mainly attributable to a significant reduction of the root biomass in combined N and D treatments, limiting the plants’ capability to satisfy their water demands. Significant seed family effects and interactions of seed family with N and D treatments across response variables suggest a high within-population genetic variability. In conclusion, our findings indicated a high drought sensitivity of Cantabrian beech populations, but also interaction effects of N and D on growth responses of beech seedlings.