Biotic communities experienced significant changes in recent decades. Climate change, the overexploitation of natural resources and the immigration of invasive species are major drivers for this change and present unknown challenges for communities worldwide. To assess the impact of these drivers, standardised long-term studies are required, which are currently lacking for many species and ecosystems. Analysing environmental samples and the DNA of associated organisms using metabarcoding and high-throughput sequencing provides a cost-efficient and rapid way to generate the high-resolution biodiversity data which is so direly needed. In this thesis, I demonstrate the great potential of using samples from the German Environ- mental Specimen Bank (ESB), a long-term monitoring archive that has been collecting and cryogenically storing highly standardised environmental samples since 1985. Modern analytical methods enable retrospective long-term biodiversity monitoring using these samples. In the first chapter, I illustrate metabarcoding as a central method, discussing its strengths and drawbacks, how to avoid them, and new application approaches. This chapter provides the methodological basis for the following studies. In subsequent chapters, I present time series analyses of communities associated with these environmental samples. While for Chapter two the focus is on terrestrial arthropod communities, in Chapter three aquatic and terrestrial communities across the tree of life are analysed. A null model was developed for this survey for robust conclusions. The studies covered the last three decades and revealed substantial compositional changes across all ecosystems. These changes deviated significantly from the model, indicating that the changes are occurring faster than expected. Moreover, a trend toward homogenization in many terrestrial communities was uncovered. Climate change and the immigration of invasive species in combination with the loss of site-specific species are suspected to be the main drivers for this. In a follow-up study, changes of arthropod communities in German and South Korean terrestrial ecosystems were compared using ESB leaf samples from these two countries. Since both ESBs are harmonised in sample collection and processing, comparative analyses were applicable. This research covered the last decade and revealed substantial declines in species richness in Korea. Abiotic and biotic factors are discussed as potential drivers of these results. Finally, the possibility of assessing tree health by analysing changes in functional fungal groups using German ESB samples was investigated. The results indicate that increasing infestation of specific functional groups is a proxy for declining tree health, with further analyses planned. In this dissertation, I present the great potential of samples from long-term monitoring archives to conduct retrospective biodiversity trend analyses across the tree of life. As technologies evolve, these samples will help to understand past and predict future ecosystem changes.

Immer wieder tauchen Fragen nach dem Stüve-Diagramm und seiner Benutzung auf. Es gibt zwar neben der Vorlesung “Einführung in die Meteorologie” auch erklärende Darstellungen in den empfohlenen Lehrbüchern und im Internet. Diese scheinen aber offenbar nicht zufriedenstellend zu sein. Deshalb habe ich nachfolgend versucht, die Antworten auf die häufigsten Fragen in Form einer Anleitung zusammen zu fassen. Ich danke em. Prof. Dr. Alfred Helbig, der im Rahmen seiner früheren Tätigkeit im operationellen Dienst umfangreiche praktische Erfahrung mit Radiosonden-Aufstiegen erworben hat, sowie Dr. Micha Gryschka (Institut für Meteorologie und Klimatologie, Leibniz Universität Hannover) für die hilfreichen Kommentare zum Manuskript.

Der Trierer Wohnungsmarkt ist in den vergangenen Jahren durch steigende Mieten gekennzeichnet. Dies führt zu Herausforderungen für die Bevölkerung, insbesondere für einkommensschwächere Haushalte. In diesem Atlas zeigen wir diese Entwicklung der Angebotsmieten auf und verdeutlichen, dass der Mietwohnungsmarkt in Teilmärkte segmentiert ist. Angesichts der Preissteigerungen über alle Segmente hinweg ist es notwendig, dass die Diskussion um bezahlbaren Wohnraum und gezielte stadtpolitische Maßnahmen stärker in den Fokus rückt, um langfristig eine soziale Stadtentwicklung Triers zu gewährleisten. Mit diesem Atlas wollen wir daher stadtpolitisch Aktiven und anderen Interessierten Materialien an die Hand geben, um die Wohnungspolitik der Stadt einordnen zu können.

Veterinärantibiotika werden weltweit in großem Umfang zur Behandlung von Tierkrankheiten eingesetzt. Aufgrund der schlechten Resorption der Mittel im Darm der Tiere gelangen sie zum Großteil unverändert über Ausscheidungen auf landwirtschaftliche Nutzflächen. Dort können sie von Nichtzielorganismen, wie Gefäßpflanzen, aufgenommen werden und deren frühe Entwicklung bedrohen. In diesem Kontext wurde bisher vor allem der Einfluss auf Kulturpflanzen untersucht, während Wildpflanzenarten des ökologisch bedeutsamen Kulturgraslandes, die vor allem durch Gülleausbringung in Kontakt mit Antibiotikastoffen kommen, deutlich weniger fokussiert wurden. Deshalb wurde in dieser Arbeit der Einfluss realistischer Konzentrationen (0,1 - 20 mg/L) zweier häufig verwendeter Veterinärantibiotika, Tetracyclin und Sulfamethazin, auf die Keimung und das frühe Wachstum von typischen Arten des temperaten Kulturgraslandes untersucht. Da in der Natur oft mehrere Stressoren gleichzeitig auf einen Organismus einwirken, wurden auch zwei Multistressszenarien, nämlich Pharmazeutikamischungen und das Zusammenspiel von pharmazeutischem Wirkstoff mit abiotischen Bedingungen (Trockenstress) untersucht. In vier Themenblöcken wurden sowohl standardisierte Laborversuche als auch naturnähere Topf- und Feldversuche durchgeführt. Die Ergebnisse zeigten, dass sowohl die Keimung als auch das frühe Wachstum durch beide Wirkstoffe, jedoch häufiger durch Tetracyclin, beeinträchtigt wurden. Während die Keimung uneinheitlich in Bezug auf die Effektrichtung beeinflusst wurde, zeigte sich eine starke, antibiotika- und konzentrationsabhängige Reduktion der Wurzellänge vor allem durch Tetracyclin, in den Petrischalenversuchen (20 mg/L bis 96 %, bei Dactylis glomerata). Das oberirdische Wachstum (Blattlänge, Wuchshöhe, Biomasse) wurde geringer beinflusst, und dabei oft wachstumsfördernd. In der gesamten Arbeit zeigten sich immer wieder Hormesis- Effekte, d.h. geringe Konzentrationen, die stimulierend wirkten, während höhere Konzentrationen toxisch wirkten. Die betrachteten Kombinationen verschiedener Faktoren führten entgegen der Erwartung nicht eindeutig zu stärkeren oder alleinigen Einflüssen. In einzelnen Fällen zeigten sich solche Muster, jedoch wurden auch Verluste von Einzeleffekten bei den Kombinationen beobachtet oder Einzeleffekte, die sich dort erneut abbildeten. Es zeigten sich, wenn auch uneinheitlich, signifikante Einflüsse auf die frühen Entwicklungsstadien von typischen Wildpflanzenarten, die bereits durch andere Faktoren einen Rückgang erfahren. Gerade im Hinblick auf die wiederholte Ausbringung von Gülle und die potenzielle Akkumulation dieser hoch persistenten Stoffe stellen Veterinärantibiotika einen weiteren wichtigen Einflussfaktor dar, der die Biodiversität und Artzusammensetzung gefährdet, weshalb zu einem umweltbewussten Umgang mit ihnen geraten wird.

Physically-based distributed rainfall-runoff models as the standard analysis tools for hydro-logical processes have been used to simulate the water system in detail, which includes spa-tial patterns and temporal dynamics of hydrological variables and processes (Davison et al., 2015; Ek and Holtslag, 2004). In general, catchment models are parameterized with spatial information on soil, vegetation and topography. However, traditional approaches for eval-uation of the hydrological model performance are usually motivated with respect to dis-charge data alone. This may thus cloud model realism and hamper understanding of the catchment behavior. It is necessary to evaluate the model performance with respect to in-ternal hydrological processes within the catchment area as well as other components of wa-ter balance rather than runoff discharge at the catchment outlet only. In particular, a consid-erable amount of dynamics in a catchment occurs in the processes related to interactions of the water, soil and vegetation. Evapotranspiration process, for instance, is one of those key interactive elements, and the parameterization of soil and vegetation in water balance mod-eling strongly influences the simulation of evapotranspiration. Specifically, to parameterize the water flow in unsaturated soil zone, the functional relationships that describe the soil water retention and hydraulic conductivity characteristics are important. To define these functional relationships, Pedo-Transfer Functions (PTFs) are common to use in hydrologi-cal modeling. Opting the appropriate PTFs for the region under investigation is a crucial task in estimating the soil hydraulic parameters, but this choice in a hydrological model is often made arbitrary and without evaluating the spatial and temporal patterns of evapotran-spiration, soil moisture, and distribution and intensity of runoff processes. This may ulti-mately lead to implausible modeling results and possibly to incorrect decisions in regional water management. Therefore, the use of reliable evaluation approaches is continually re-quired to analyze the dynamics of the current interactive hydrological processes and predict the future changes in the water cycle, which eventually contributes to sustainable environ-mental planning and decisions in water management. Remarkable endeavors have been made in development of modelling tools that provide insights into the current and future of hydrological patterns in different scales and their im-pacts on the water resources and climate changes (Doell et al., 2014; Wood et al., 2011). Although, there is a need to consider a proper balance between parameter identifiability and the model's ability to realistically represent the response of the natural system. Neverthe-less, tackling this issue entails investigation of additional information, which usually has to be elaborately assembled, for instance, by mapping the dominant runoff generation pro-cesses in the intended area, or retrieving the spatial patterns of soil moisture and evapotran-spiration by using remote sensing methods, and evaluation at a scale commensurate with hydrological model (Koch et al., 2022; Zink et al., 2018). The present work therefore aims to give insights into the modeling approaches to simulate water balance and to improve the soil and vegetation parameterization scheme in the hydrological model subject to producing more reliable spatial and temporal patterns of evapotranspiration and runoff processes in the catchment. An important contribution to the overall body of work is a book chapter included among publications. The book chapter provides a comprehensive overview of the topic and valua-ble insights into the understanding the water balance and its estimation methods. Moreover, the first paper aimed to evaluate the hydrological model behavior with re-spect to contribution of various sources of information. To do so, a multi-criteria evaluation metric including soft and hard data was used to define constraints on outputs of the 1-D hydrological model WaSiM-ETH. Applying this evaluation metric, we could identify the optimal soil and vegetation parameter sets that resulted in a “behavioral” forest stand water balance model. It was found out that even if simulations of transpiration and soil water con-tent are consistent with measured data, but still the dominant runoff generation processes or total water balance might be wrongly calculated. Therefore, only using an evaluation scheme which looks over different sources of data and embraces an understanding of the local controls of water loss through soil and plant, allowed us to exclude the unrealistic modeling outputs. The results suggested that we may need to question the generally accept-ed soil parameterization procedures that apply default parameter sets. The second paper attempts to tackle the pointed model evaluation hindrance by getting down to the small-scale catchment (in Bavaria). Here, a methodology was introduced to analyze the sensitivity of the catchment water balance model to the choice of the Pedo-Transfer Functions (PTF). By varying the underlying PTFs in a calibrated and validated model, we could determine the resulting effects on the spatial distribution of soil hydraulic properties, total water balance in catchment outlet, and the spatial and temporal variation of the runoff components. Results revealed that the water distribution in the hydrologic system significantly differs amongst various PTFs. Moreover, the simulations of water balance components showed high sensitivity to the spatial distribution of soil hydraulic properties. Therefore, it was suggested that opting the PTFs in hydrological modeling should be care-fully tested by looking over the spatio-temporal distribution of simulated evapotranspira-tion and runoff generation processes, whether they are reasonably represented. To fulfill the previous studies’ suggestions, the third paper then aims to focus on evalu-ating the hydrological model through improving the spatial representation of dominant run-off processes. It was implemented in a mesoscale catchment in southwestern Germany us-ing the hydrological model WaSiM-ETH. Dealing with the issues of inadequate spatial ob-servations for rigorous spatial model evaluation, we made use of a reference soil hydrologic map available for the study area to discern the expected dominant runoff processes across a wide range of hydrological conditions. The model was parameterized by applying 11 PTFs and run by multiple synthetic rainfall events. To compare the simulated spatial patterns to the patterns derived by digital soil map, a multiple-component spatial performance metric (SPAEF) was applied. The simulated DRPs showed a large variability with regard to land use, topography, applied rainfall rates, and the different PTFs, which highly influence the rapid runoff generation under wet conditions. The three published manuscripts proceeded towards the model evaluation viewpoints that ultimately attain the behavioral model outputs. It was performed through obtaining information about internal hydrological processes that lead to certain model behaviors, and also about the function and sensitivity of some of the soil and vegetation parameters that may primarily influence those internal processes in a catchment. Accordingly, using this understanding on model reactions, and by setting multiple evaluation criteria, it was possi-ble to identify which parameterization could lead to behavioral model realization. This work, in fact, will contribute to solving some of the issues (e.g., spatial variability and modeling methods) identified as the 23 unsolved problems in hydrology in the 21st century (Blöschl et al., 2019). The results obtained in the present work encourage the further inves-tigations toward a comprehensive model calibration procedure considering multiple data sources simultaneously. This will enable developing the new perspectives to the current parameter estimation methods, which in essence, focus on reproducing the plausible dy-namics (spatio-temporal) of the other hydrological processes within the watershed.