From Gene to Ecosystem – Retrospective molecular biodiversity monitoring of plant-associated arthropod communities and abiotic stress on plants

This thesis serves as proof of concept for the tensile strength simulation-based nonwoven material design. Objective is the adjustment of the parameters of an underlying production process with regard to a desired tensile strength behavior (optimization). As an example, we focus on the nonwoven airlay production and consider a thermobonding procedure for the consolidation of the nonwoven fabrics. To be able to map production parameters to the associated tensile strength behavior, we present a model-simulation framework composed of a model for the nonwoven fiber structure generation and a model for the nonwovens’ mechanical behavior under vertical load. The model for the fiber structure generation replicates the stochastic fiber lay-down of the airlay production and results in a random three-dimensional fiber web. This web is consolidated using a virtual bonding procedure that mimics the thermobonding of the nonwoven material. The topology of the resulting adhered fiber structure can be described by a graph, which serves as basis for the subsequent tensile strength simulation. The model used for this purpose describes the mechanical behavior of the material at fiber network level. Therefore, the considered fiber structure sample is interpreted as truss and the fiber connections are equipped with a nonlinear material law, which allows to describe the elastic phase of the nonwovens’ tensile strength behavior. The existence and uniqueness of a solution to the model as well as its numerical treatment are discussed. Moreover, we present data reduction strategies that enable more efficient simulations by removing fiber structure parts that do not contribute to the tensile strength behavior. As it becomes evident from the numerical experiments, a single tensile strength simulation for a production-like virtual sample is already computational demanding. Costs accumulate further, since Monte-Carlo simulations are required to account for the randomness in the fiber structure generation. Thus, direct simulations provide an infeasible basis for the nonwoven material design. This motivates the use of a predictive surrogate for optimization. Therefore, we consider regression-based approaches at different levels of information within the simulation framework. It turns out that the coupling of a polynomial model, for the fiber structure feature inference, with a linear one, for the stress-strain curve inference, yields accurate predictions. Once trained, the regression models allow for efficient evaluations and thus represent a suitable surrogate for the nonwoven material design. In this context, we discuss two exemplary problems of interest for the application: First, a tracking-type problem that aims to find the production parameters that result in a desired tensile strength behavior, expressed in terms of stress-strain curves. Second, an in-corridor maximization problem, which aims to identify the production parameters that maximize the probability of ending up in a specified stress-strain corridor.

The article discusses “SimStab” [Simulator of Stability], a poetic performance by a young Russian poet, Rostislav Amelin, as an effective hybrid of the innovative poetry, video game, and the cyberpunk genre models. The interaction of these components produces strong, yet not necessarily obvious political over-tones, testing the limits of the audience’s (or readers’, or players’) agency. Like many other cyberpunk texts, “SimStab” explores the conflict between the desire to resist colonization by the pervasive powers dominating contemporary society, and the absolute necessity of willingly colonizing your own body and subjectivity with the products of these powers. Both the poem, game and their shared text embody spaces of utopia reliant on repressed sites of formless abjection, which paradoxically become a source of anarchic freedom. Thus, in “SimStab” the ludic algorithmic with its procedural rhetoric (Ian Bogost) creates spaces of formlessness which repeats the liberatory promise of cyberpunk literature.

The target of this essay is to open possible pathways to approach the phenomenon of a self-remodeling of classicist poetry in the 20th and early 21st century by focusing on the process from two different angles rarely perceived as related to each other: first, the remodeling of Chinese lyrical classicism through a strand of modern American poetry harking back to Ezra Pound and currently crystallized in the translations of David Hinton and, second, the transition that modern Chinese poetry written in classical language and conforming to prosodic rules of classical style poetry, sometimes referred to as “old style poetry” jiu ti shi, underwent after its rebirth as “unofficial” poetry online since the beginning of this century. Although there are obviously no direct links between the aforementioned tradition of modern American poetry and neoclassicist cyberpoets like Zeng Shaoli I argue that in both cases the classicist inspiration and poetic drive is motivated by concern with the increasing imbalance between natural, social, and individual resources, on the one hand, and an indomitable desire to accumulate economic and political power on the other. A permanent devaluation of language in the human realm, matched by a permanent devaluation of currencies in the economic sphere, provokes poetic responses in the very interest of humanity. The neoclassicist lyricisms that I draw into comparison display both subtle distinctions and common traits in this response to the starkly different environments of their respective contemporary literary scenes.

This volume brings together contributions addressing the intersections of political poetry, performativity, and the internet. The essays are based on presentations given at workshops and conferences organized by the DFG Centre for Advanced Studies “Russian-Language Poetry in Transition: Poetic Forms of Dealing with Boundaries of Genre, Language, Culture and Society between Europe, Asia and America” (2017-2023). The conferences took place in 2018-2019, at a time when neither the coronavirus pandemic nor Russia’s brutal invasion of Ukraine were foreseeable, and the contributions have not been updated in light of these catastrophes. The articles presented here deal with recent poetry and focus on the connection between politics, performativity, and the internet in multiple literatures and intercultural relations. Although the majority of these texts belong to the Russophone world, poetry from Serbia, Latvia, and China is also considered. The contributors demonstrate, on the one hand, how newer poetry softens genre distinctions and formally tends towards multimedia hybridization and, on the other, how it transcends or dissolves linguistic, cultural, and social boundaries. Dr. Ekaterina Friedrichs and Ms. Lena Rosalin Schwarz were involved in preparing this publication for printing. We would like to thank them both for their careful review and wonderful cooperation.

Departing from Roland Barthes’ association of text and textile, and feminist theory on weaving as text production, this article analyzes the textile qualities of Inger Christensen’s “Letter in April” (1979) and Amalie Smith’s “Thread Ripper” (2020). In “Letter in April”, Christensen establishes a connection between writing and spinning or weaving through their shared temporality of varied repetition. In “Thread Ripper” Smith alludes to Christensen and makes of the continuity between text and textile not only the main theme of the book, but also its structuring principle. Through a materialist conception of the text, regarding it as a woven fabric, the article focuses on the textual patterns of the two works (stylistic figures in Christensen, graphic composition in Smith). The connection from Christensen to Smith leads to a further connection to ecocritical conceptions of weaving as no less than a cosmological principle. On a concluding note, the article argues that weaving is not only connecting, but also disconnecting, cutting.

This article discusses the high regard for Danish poet Inger Christensen in Germany and her connection to the Künstlerhaus [Artists’ Residence] in Edenkoben, located in Rhineland-Palatinate. The Künstlerhaus serves as a cultural institution where international artists from various fields can reside and collaborate. Inger Christensen had strong connections with the Künstlerhaus Edenkoben and participated in its German-Danish poetry project. During her visits to Edenkoben, she wrote several poems. In an essay, the poet described Edenkoben’s landscape as paradise-like. This article, on the one hand, examines these texts in the context of Inger Christensen’s stay in Edenkoben. On the other, it sheds light on “Weg der Gedichte”, a project that stages Inger Christensen’s poem “Erinnerung an Edenkoben” in a public space around the Künstlerhaus, showcasing the role of poetry in rural settings and its ability to enhance the experience of nature and hiking.

This article examines “China” in contemporary American poetry using the example of Timothy Yu’s poems, titled “Chinese Silence,” which rewrite and / or parody texts from the American literary canon as well as public communication. It proposes a hall-of-mirrors reading of these poems in order to show how Yu’s poems refer to, reflect on, and relocate other authors’ writing of “China.” It argues that Yu’s poems, instead of making claims for an authentic “China,” attempt to bring Chinese Americans’ lived experience into the American literary tradition.

In this article, I analyze the character of hyper-naturalism and exaggerated tactility in dramatic poems by contemporary Russian-Georgian philosopher and writer Keti Chukhrov. I argue that, while descriptions of violence, physiological functions, and abject poverty are common for post-Soviet art, in Chukhrov’s work these elements perform radically different task than in the pessimistic and de-ideologized chernukha, or the style of grim realism. Her approach to matter is also distinct from the historic Russian avant-garde tradition, which relished intensified sensations but did not offer constructive ways of inscribing their immediacy into coherent cultural continuity. Instead, her dramatic poems bear pedagogical, even rehabilitative stakes for recuperating the individual sensations of alienated people into meaningful and shared cultural experiences. In this article, I discuss her approach to drama as mobilizing the tradition of Soviet Marxist defectology, a special educational method of socializing disabled, cognitively impaired, or otherwise disadvantaged people. Pioneered in the Soviet Union in the 1920s by Lev Vygotsky and suppressed in the 1930s, defectology found further application in the 1960s and 1970s in the work of the Zagorsk boarding school for the deafblind, led by Vygotsky’s student Alexander Mescheriakov and Evald Ilyenkov, a Marxist-Hegelian philosopher who is a central figure for Chukhrov’s philosophical research. One of the key tasks of Meshcheriakov and Ilyenkov was to help their deafblind students to overcome isolation through learning to translate their purely tactile sensations into deliberate communicative acts. While Zagorsk offered Ilyenkov an opportunity to test and apply his theory of the collectivist formation of personality, for Chukhrov it is theater that has become the sphere for experimental, practical extension of her scholarly research into Soviet Marxist thought and socialist culture of the 1960s and 1970s. Her dramatic texts offer models of alternative subjectivization for post-Soviet people to allow themselves once again to recognize the presence of universal values and greater cultural commons behind individual, alienated sensations and experiences.

Russian feminist poetry has flourished in the post-Soviet period, especially the last decade. It has provided inspiring modes of resistance to all forms of indifference to bodily harms, particularly the harms to women. That poetry is studied here through the lens of feminist theory. The essay argues that a wide range of such theories finds resonance in these poems, and it introduces several key poets: Galina Rymbu, Oksana Vasiakina, Lida Yusupova, Elena Fanailova, and Mariia Stepanova, with a coda on Konstantin Shavlovskii.

On the “Flowing Movement” and the “Lofty and Ancient” in Gary Snyder’s Poetry Gary Snyder, a renowned 20th century American poet, has been strongly influenced by Eastern cultures, especially Chinese. The philosophical spirit of Eastern culture and its intuitive way of thinking have taken root in Snyder’s mind and directly shaped his perception of nature. Hence, in view of the inadequacy of Western literary criticism in interpreting the Eastern dimensions of Snyder’s poetry, this article takes the classical Chinese literary theory “Twenty-Four Styles of Poetry” as its theoretical perspective and uses its categories of “Flowing Movement” and “Lofty and Ancient” to explore how the dissolved or solitary poetic self achieves the mental state of “emptiness” (kong in Chinese Taoism and sunyata in the Buddhist sense) and creates the poetic worlds of the “flowing movement” and the “lofty and ancient” (transcendence) in Snyder’s poems.

This article aims to reconstruct the reception of pre-Socratic philosophy, especially that of Parmenides, in Russian modernism and avant-garde literature. In doing so, it places this reception into two contexts: the contemporary discussion of pre-Socratic ideas in Russian, European and American philosophy, on the one hand, and the proclamation of a third, a Russian and/or Slavic Renaissance, on the other. This Renaissance has been conceived as the intense discussion and reconsideration of ideas, notions, and expressions of ancient Greek thinking. It aimed also to avoid the reduction of Greek philosophy to Plato, as had been practiced by the Russian Orthodox Church and largely pushed through in Russian culture. One of the main points of this reconsideration concerned the quest of the relation between the word, the process of thinking, and human life, while another one connected with it involved the (re-)establishment of a close bond between the poetic word, its meaning, and its sense. The integration of this productive discussion with pre-Socratic Greek philosophy enriches and improves our knowledge of Russian modernism and avant- garde literature.

Pastoral serves as a keyword when understanding Seamus Heaney’s literary production, both in terms of stylistic features and imagery. Although critical attention has focused on the connection between his pastoral works and contemporary Irish politics, the growth of ecocritical scholarship in the last few decades has made evident the importance of broadening such an analytical scope to relationships between humans and the environment while studying this genre. In this alignment, the present essay offers an ecocritical reading of some selected pastoral poems by Heaney, with a specific focus on his revival of the eclogue through the collection “Electric Light” (2001). Precisely, the poems “Virgil: Eclogue IX,” “Bann Valley Eclogue,” and “Glanmore Eclogue” will be read through the innovative perspective offered by the recent engagement of affect theory with ecocriticism: by doing so, I argue that Heaney’s poems can be understood as valuable nature narratives that stress the connectedness between the human and the nonhuman, while resonating with the urgencies posed by the current environmental crisis to re-think more ethical forms of relationships between them. Furthermore, through the lens of econarratology, attention will be paid to the ecological potentials expressed by the formal features of the eclogue: this observation considers, on the one hand, the notion of ‘relationality’ within the practice of the shepherds’ dialogue/singing and, on the other hand, how this literary form stresses the attachment between the human and the environment, both in the real world and in the storyworld. Hence, when exceeding a strictly politically oriented critical analysis of his work, Heaney’s eclogues become visible as compelling ecocritical accounts that favor investigating the role of (pastoral) literature in fostering critical discussions about human/nonhuman ethics as a way to respond to the challenges of the Anthropocene.

In the last chapter of “De coniecturis”, Cusanus exhorts his friend, Cardinal Giuli ano Cesarini, to get to know himself. This classical philosophical topic is revisited by Cusanus here in an original manner. On the one hand, Cusanus’ perspective reveals the strong influence of Proclus, which deserves to be highlighted. On the other, unlike Proclus, Cusanus asserts that self-knowledge is explicitly linked to the topic of the human being as created ad imaginem and that of the world as the sphere of contraction. Cusanus bases both subjective matters on the triune princi ple. According to him, the Divine Trinity is the exemplar that cannot be reached by an image, and the effort to reach the Trinity constitutes the basic requirement for the conjectural construction of the self. Furthermore, the fact that this under standing of the Trinity implies a distinction in itself makes the Trinity the princi ple of all difference or otherness in plurality. Cusanus concludes that the image can only be constructed relationally, that it is not possible to attain God without a fundamental knowledge of the self as an image, and that no one knows his own self without knowing others at the same time.

This essay applies a Cultural Studies-approach to the multi-facetted relationship between poetry and advertisement as it emerged in the first half of the 20th century in the United States and as it became visible on billboards by the roadside. Somewhat paradoxically, public poetry in advertising appeared all across the United States (predominantly along highways in rural areas) around the time that much of modernist American poetry was being declared a highly elitist and urban centric affair in the orbit of new criticism-scholarship at universities. My first case study addresses the iconic Burma-Shave Billboard Poetry Campaign (1929-1963) and its long-lasting influence on American (popular) culture – in literature, music, visual art. Prior to this campaign as well as on the heels of it, billboards and billboard poetry were taken up to a minor extent in poetry circles and literary criticism (where they continued to be mostly viewed with disdain) and to a larger extent by conceptual artists who used billboard aesthetics, slogans, and short (poetic) texts in installations mimicking and critiquing consumer culture. One of the most aesthetically innovative recent ‘returns’ of billboard poetry, however, is the one employed intra-diegetically in the Hollywood film “Three Billboards Outside of Ebbing, Missouri” (2017), my second case study. Here, the writing on the billboard-walls make those aspects explicit that have been submerged in the earlier rhymes by the roadside: While the playful, optimistic lines of advertisement imply, time and again, a happy white middle-class American family with a sober and well-shaved patriarch behind the wheel and thus gloss over the disavowed underside of mobility, the film makes the latent manifest and points to systemic / structural violence, such as a pervasive American rape ‘culture’ which is linked to the car and the mobility it offers. The film uses the billboard and its inscription as foil and as catalyst to address and to protest this and other forms of violence and thus presents an activist intervention in order to ask for more than merely poetic justice.

This essay identifies a shared response to news media in poetry written over the past three decades by writers working in Chinese, Russian, and English. These poets often directly incorporate texts and images from news media into their work. Some scholars have argued that this tendency towards the collaging of texts derived from news and social media reflects a shift in poetic subjectivity. However, when seen from a comparative perspective, these and other cut-ups of news and social media are better understood as, on the one hand, an extension of a much longer tradition of literary and artistic responses to the news and, on the other, a renewal of that tradition in response to the intensification of the intertwined pressures of new media and globalization since the end of the Cold War and the rise of the Internet. The article identifies this shared response to media and globalization among a variety of examples in Chinese, Russian, and English, including Kirill Medvedev’s «Текст, посвященный трагическим событиям 11 сентября в Нью-Йорке» (“Text Devoted to the Tragic Events of September 11 in New York”); Stanislav Lvovsky’s «Чужими словами» (“In Other Words”); Dmitri Prigov’s «По материалам прессы» (“Based on Material from the Press”) and “ru.sofob (50 x 50)”; Lin Yaode’s 林燿德 “Er erba” 《二二八》(“February 28”), Hsia Yü 夏宇 and her collaborators’ group project “Huadiao huadiao huadiao” 《劃掉劃掉劃掉》 (“Cross It Out, Cross It Out, Cross It Out”), Yan Jun’s 顏峻 2003 multi-media video performance “Fan dui yiqie you zuzhi de qipian” 《反对一切有组织的欺骗》 (“Against All Organized Deception”); online video poetry produced in response to the 2008 Sichuan earthquake; and Brian Kim Stefans’s mashup of “New York Times” articles with texts from the Situationist International. On the one hand, these texts operate between various media and art forms: between poetry and contemporary art, music, journalism, and social media, between the print newspaper and digital file, between the webpage and live performance, and between image and text. But on the other hand, and inextricably, they also operate within global information networks. They are better understood as addressing not the transformation of the poetic subject but the undoing of the boundaries of poetry and of the concept of a nationally defined literature.

The article offers a preliminary investigation of the phenomenon of female-authored ‘poetry theater’ (shige juchang)1 in the People’s Republic of China. It discusses cross-genre explorations by a group of female poets, theater directors and artists who are all associated with the movement of ‘women’s poetry’ (nüxing shige) that emerged in the 1980s in China. The discussion focuses on two performances based on female-authored poems, “Riding a Roller Coaster Flying Toward the Future” (2011) and “Roaming the Fuchun Mountains with Huang Gongwang” (2016), which resulted from the joint efforts of four women: the poet Zhai Yongming, the poet-scholar Zhou Zan, and the theater directors Cao Kefei and Chen Si’an. Their avant-garde experiments with poetical theater document the different ways in which poetry is being translated into images, sounds, or bodily movements on stage. The paper argues that poetic exploration of writing and reciting practices has gained new momentum from emerging intermedial, visual-verbal experiments. Furthermore, it claims that interest in ‘poetry theater’ is also driven by the search for new forms of cross-genre stage performances that could be different from the previously politicized or commercialized ones.

Starting from the imperative to not just read, but to speak lyric poems out loud, this paper considers ways in which poems change depending on who utters them. Beyond the familiar distinction between the poem’s author and the lyrical ‘I’ – the voice in which the poet chooses to utter the poem – any performer who speaks a poem also impersonates the text. Reading is the first act of interpretation; others follow. Sound is an indispensable constitutive aspect of the lyric poem, too often neglected. Each reading of a poem can turn into a momentary ec-stasis.

A new genre has emerged in contemporary literature: the ‘novel in poems.’ This genre hybridizes the novel and poetry in order to construct characters and a plot through relatively autonomous poems in series. The ‘novel in poems’ appears in different subtypes, which can be categorized according to the following criteria: (1) the presence of one speaker versus several speakers, (2) the presence of a speaker as lyric protagonist and/or narrator, and (3) the presence of a blend of distinct modes of lyric, narrative, and dramatic representation in various forms of combination. Specific characteristics of the ‘novel in poems’ are: 1) variation of constituent poetic forms with different degrees of semantic autonomy and brevity; 2) hyper-structuring through symmetries, holism, and equivalences; 3) a tendency to differentiate mediating instances within the text; 4) the reduction or elimination of the narrator or of narrative principles and the use of an omnipresent textual subject; 5) the presence of metapoetic reflections on topics such as poetry and creativity; 6) an emphasis on voice, person, and subjectivity; 7) episodic plot construction through montage techniques and a tendency toward chronological order; 8) the predominance of present speech and action; 9) contradictions between the speaker as subject and addresser, via the lyric fiction of performativity, and the function of narration; 10) a necessity imposed upon the reader to reconstruct the plot and characters. This essay establishes three subtypes within the proposed genre: a lyric ‘novel in poems’ with one speaker (Irina Ermakova), a polyphonically narrative ‘novel in poems’ that combines third-person narration with several alterior speakers (Lana Hechtman Ayers), and, finally, a dramatic ‘novel in poems’ with shifting primary speakers (Glyn Maxwell).

More than any other literary form, contemporary poetry is in transition: interspersed with narrative and dramatic genres, combining prose and verse, and even incorporating other media, such as visual arts, music, film, and digital technology. It shifts the borders between public and private spheres, aesthetic and discursive approaches, and producer and recipient. On the basis of case studies, this issue addresses the challenges of poetry in transition and stimulates new approaches in lyric theory and methodology.

Income composition can have a significant impact on workers’ well-being, productivity, and career paths. Wages often include a variety of components, such as unconditional bonuses, profit-sharing payments, and incentives based on the individual performance of employees. Each of these may influence employee labour outcomes differently and the worker composition may matter for managers when designing the salary package. Simultaneously, workers’ employment choices and well-being are influenced by income outside the job, such as inheritances and lottery winnings, as well as by external factors like technological change. This dissertation includes five empirical studies that investigate these issues, yielding new insights on the role of monetary gifts, financial incentives, labour market institutions, and technology disruptions in affecting employees’ labour and well-being outcomes.

Many developed countries, including Germany, face a steady rise in the share of individuals obtaining higher education. While rising education itself bears a series of advantages as extensively studied in previous literature, it is also conceptually linked to a higher likelihood of working in an occupation that does not match one’s formal qualifications. Previous studies have predominantly evaluated how demographic or job‐related aspects correlate with the likelihood of being educationally ﴾mis﴿matched. However, they have largely ignored institutional facets of the educational system or industrial organization. Moreover, little is known about how private wealth affects educational mismatch or whether job satisfaction is homogenously affected among individuals once such a mismatch occurs. The five projects collected in this thesis aim to answer these open questions in the literature for Germany, using data from the Socio‐Economic Panel and employing different time intervals between 1984 and 2022. Beginning with the educational system in early childhood, Chapter 2 evaluates the impact of school‐starting age on the likelihood of over‐ and undereducation. It exploits the exogenous variation in school‐entry rules across federal states and years in Germany with regression discontinuity designs. The results report a negative impact of school‐starting age on the likelihood of undereducation, but no systematic relationship with overeducation. Subsequently, Chapter 3 explores the variation in education costs by leveraging the quasi‐experimental setting induced by the time‐limited introduction of tuition fees in several German federal states between 2006 and 2014. The increase in education costs among treated graduates results in a significantly higher likelihood of overeducation, which endures even several years post‐graduation. Chapter 4 focuses on the industrial relations system and examines the correlation between trade union membership and the likelihood and extent of educational ﴾mis﴿match. The results reveal that trade union members report significantly less overeducation at both the intensive and extensive margin and also a higher likelihood of being matched compared to non‐members. Furthermore, the heterogeneity analysis provides evidence that this correlation is driven by improved bargaining power instead of informational advantages. Chapter 5 focuses on private wealth as a determinant of educational mismatch by investigating the impact of a wealth shock through inheritances, lottery winnings or gifts on the likelihood of over‐ and undereducation. Due to the diminishing marginal returns of wages with increasing windfall gains the likelihood of undereducation is expected to decrease, while that of overeducation is expected to increase. Empirically, these suppositions are supported for overeducation, as its likelihood increases significantly after the windfall gain. Further analyses reveal that this effect is driven by individuals switching occupations while increasing their leisure time, and it materializes only for medium to large windfall gains. Contrary to the previous chapters, Chapter 6 focuses on educational mismatch, more precisely on overeducation, as the independent variable. In particular, it investigates the correlation between overeducation and job satisfaction. The results align with the previously established negative correlation for private sector employees exclusively. In contrast, interaction and subsample analyses reveal a positive correlation for public sector employees. This link is driven by individuals with a high degree of altruistic motivation and family orientation.

Measuring the economic activity of a country requires high-quality data of businesses. In the case of Germany, this is not only required at national level, but also at federal state level and for different economic sectors. Important sources for high-quality business data are the business register and, among others, also 14 business surveys which are conducted by the Federal Statistical Office of Germany. However, the quality requirements of the Federal Statistical Office are in contrast to the interests of the businesses themselves. For them, answering to a survey's questionnaire is an additional cost factor, also known as response burden. A high response burden should be avoided, since it can have a negative impact on the quality of the businesses' responses to the surveys. Therefore, sample coordination can be used as a method to control the distribution of response burden while securing high-quality data. When applying already existing business survey coordination systems, developed by different statistical institutes, legal and administrative standards of German official statistics have to be taken into account. These standards consider different sampling fractions, rotation fractions, periodicity, and stratification of the aforementioned 14 business surveys. Therefore, the aim of this doctoral thesis is to check the existing business survey coordination systems for their applicability in the context of German official statistics and, if necessary, to modify them accordingly. These modifications include the introduction of individual burden indicators which aim to take the individual perception of response burden into account. For this purpose, several synthetic data sets have been created to test the application of the modified versions of the different business survey coordination systems through Monte Carlo simulation studies. These data sets include a large panel data set, reflecting the landscape of businesses in Rhineland-Palatinate and three smaller, synthetic data sets. The latter have been created with the help of the R package BuSuCo which has been developed within the scope of this thesis. The above mentioned simulation studies are evaluated based on different measures for estimation quality as well as for the concentration and distribution of response burden.

Extracellular enzymes in microbial communities play a central role in nutrient cycling and the degradation of (pollutant) substances in various natural and anthropogenic systems. Bound in aquatic biofilms, sludge aggregates, or even unbound at their interfaces, they are of great importance for both the environment and human health. In particular, in wastewater treatment plants and inland waters, hydrolytic activities influence the wide-reaching efficiency of nutrient removal and self-purification, thus contributing significantly to overall water quality. The main goal of this dissertation project was to investigate the factors that influence enzymatic activity and the health of microbial communities in activated sludge and river systems, particularly in relation to anthropogenic influences and natural environmental conditions. The aim was to contribute to a better understanding of the sensitivity of our freshwater ecosystems and to support the long-term preservation of water quality and ecological stability. The development and optimization of appropriate methods, as well as their testing and applicability, were the focal points. For this purpose, a fluorometric microplate assay was developed and adapted to determine both extracellular enzyme activities (EEAs) in activated sludge samples and in intact biofilms. Its suitability for field studies was subsequently tested. Inhibition and activity of selected hydrolases under different conditions were investigated to better understand the mechanisms and potential environmental risks posed by anthropogenic influences and seasonal fluctuations of hydrochemical and climatic parameters. The first phase of the doctoral thesis involved studies on the inhibition of alkaline phosphatase in activated sludge by oxyanions. Using the fluorometric microplate assay, the inhibitory effect was sensitively detected over a pH range of 7.0 to 8.5. IC50- and IC20-concentrations were calculated from modeled dose-response functions. It was found that vanadate and tungstate caused strong inhibitory effects, while molybdate moderately inhibited the enzyme. An increasing pH led to a reduction in the inhibitory effect of tungstate and molybdate. The inhibition effects of vanadate were not significantly affected by the pH. In municipal wastewater, the concentrations of such metal ions are usually low, but industrial wastewater may have pollutant loads that can significantly impact the removal of phosphorus-containing compounds, and thus the efficiency of treatment plants. In the second phase, an attempt was made to further adapt the developed methodology to investigate EEA and kinetics in intact freshwater biofilms. Four different types of bead materials (lava, glass, sintered quartz, and ceramics) fitting into a 96-well microplate were tested as carriers for biofilms on both the laboratory and field scale. The analysis included a total of seven hydrolases as representatives of key nutrient cycles such as phosphorus, carbon, and nitrogen: phosphatases, glucosidases, peptidases (two different types), and sulfatase. Experiments with increasing substrate concentrations led to classical kinetic profiles according to the Michaelis-Menten mechanism. This allowed for the prediction of the biofilm enzymes’ response to different substrate concentrations. Parameters such as Vmax and Km could be derived from the modeled curves. Ceramic beads are particularly suitable for long-term studies due to their high stability, while sintered quartz beads should be preferred for the use in stagnant media (material loss under turbulent conditions). Lava and glass beads, on the other and, proved suboptimal for uniform biofilm development due to their surface properties. The potential use of this fast and sensitive test for ecotoxicological or even human-toxicological studies was demonstrated by the effects of caffeine on the activity of PDE. The result of this part of the research represents a powerful tool for assessing environmental pollution and monitoring water quality. The high application potential was clearly highlighted in the final phase of the project. The goal here was to deepen the understanding of interactions between seasonal factors, anthropogenic influences, and biofilm processes in rivers by investigating EEA and biofilm parameters such as biomass and relating them to hydrochemical and climatic factors. Ceramic beads were exposed both upstream and downstream of a wastewater treatment plant discharge and sampled over a period of seven months. EEAs and biomass varied depending on the season and location, with higher microbial activity observed upstream in winter. Winter conditions led to the dilution of most nutrients as well as in an increse of dissolved oxygen. Nutrient concentrations analyzed downstream were significantly higher in the summer. Accumulation of nutrient or pollutants during the summer months cannot be excluded, which may have led to a general reduction in enzyme activities. Potential causes could be inhibitory effects on the enzymes, or a reduced enzyme activity due to a sufficiently high nutrient supply. In general, the sampling site upstream showed a more pronounced seasonal dynamics, with a significant proportion of the variance in biological parameters (activity and biomass) attributable to seasonal factors. A secondary component, likely reflecting the impact of the treatment plant discharge, explained another portion of the data variance. Regardless of the season, high correlations between biological parameters were observed upstream, while downstream the data were more decorrelated. This could be because the biofilms, under chronic stress, respond less dynamically to seasonal fluctuations. This dissertation illustrates that in addition to anthropogenic stress factors, seasonal fluctuations of hydrochemical and climatic parameters should also be considered in "stress downstream the pipe" studies. The selected methods are recommended for explaining and considering the data variance, as they highlight the complex interplay between microbial enzymatic activity, environmental factors, and pollutants in the activated sludge of wastewater treatment plants and also in aquatic systems. The novel bead assay could pave the way for the future standardization of effect-oriented studies on intact aquatic biofilms.

The application of machine learning and deep learning methods to hydrological modelling has advanced significantly in recent years, offering alternatives to traditional conceptual and physically based approaches. Within the numerous algorithms, long short-term memory (LSTM) networks have proven themselves particularly useful for the task of streamflow modelling. This thesis provides a collection of publications that investigate the capabilities, limitations and interpretability of LSTM for the purpose of streamflow modelling and climate change impact assessment within the lowland Ems catchment in Northwest Germany. Within a comparative performance evaluation, LSTM and its predecessor, the recurrent neural network, demonstrate superior accuracy compared to the conceptual HBV model across various statistical performance metrics. However, a decline in performance was observed during low-flow conditions in certain sub-catchments. The evaluation of the flow duration curve revealed that the ML models more effectively capture the water balance, while HBV better represents streamflow dynamics. To enhance the interpretability of LSTM, six explainable artificial intelligence techniques were applied. These methods consistently identified seasonal patterns in the temporal relevance of hydroclimatic input data. In combination with an observed correlation between the internal LSTM states and catchment-scale soil moisture dynamics, the findings suggest that LSTM models are capable of implicitly learning the relevant hydrological processes. Following, the capabilities of LSTM to model climate change impact scenarios, particularly when they extend beyond historically observed climate conditions, are addressed. An ensemble of climate change projections is provided as hydroclimatic input to evaluate the performance of LSTMs and conceptual models. While all models reveal heterogeneous alterations in streamflow under future climate conditions, significant differences emerge based on the model type. Results provide evidence that LSTMs, in combination with the temperature-based Haude formula for estimating potential evaporation, work inadequately under altered climatic regimes, raising concerns about their applicability in long-term projections. The study also indicates the potential need to incorporate physical constraints into LSTM architectures to ensure model robustness and hydrological plausibility beyond the historical training range. Collectively, this thesis contributes important insights into the applicability and interpretability of LSTM models in streamflow modelling. Despite the presence of a physically realistic representation of soil moisture dynamics of the Ems catchment, no robust change signals for streamflow under climate change can be derived. Those results underscore the potential of LSTM model approaches for accurate streamflow simulation, however, they require us to always critically question LSTM results, particularly when they are applied outside the training range.