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The future performance of the widely abundant European beech (Fagus sylvatica L.) across its ecological amplitude is uncertain. Although beech is considered drought-sensitive and thus negatively affected by drought events, scientific evidence indicating increasing drought vulnerability under climate change on a cross-regional scale remains elusive. While evaluating changes in climate sensitivity of secondary growth offers a promising avenue, studies from productive, closed-canopy forests suffer from knowledge gaps, especially regarding the natural variability of climate sensitivity and how it relates to radial growth as an indicator of tree vitality. Since beech is sensitive to drought, we in this study use a drought index as a climate variable to account for the combined effects of temperature and water availability and explore how the drought sensitivity of secondary growth varies temporally in dependence on growth variability, growth trends, and climatic water availability across the species' ecological amplitude. Our results show that drought sensitivity is highly variable and non-stationary, though consistently higher at dry sites compared to moist sites. Increasing drought sensitivity can largely be explained by increasing climatic aridity, especially as it is exacerbated by climate change and trees' rank progression within forest communities, as (co-)dominant trees are more sensitive to extra-canopy climatic conditions than trees embedded in understories. However, during the driest periods of the 20th century, growth showed clear signs of being decoupled from climate. This may indicate fundamental changes in system behavior and be early-warning signals of decreasing drought tolerance. The multiple significant interaction terms in our model elucidate the complexity of European beech's drought sensitivity, which needs to be taken into consideration when assessing this species' response to climate change.

Heavy-duty vehicles (HDVs) are responsible for a significant amount of CO2 emissions in the transport sector. The share of these vehicles is still increasing in the European Union (EU); nevertheless, rigorous CO2 emission reduction schemes will apply in the near future. Different measures to decrease CO2 emissions are being already discussed, e.g., the electrification of the powertrain. Additionally, the impact of autonomous driving on energy consumption is being investigated. The most common types are fuel cell vehicles (FCEVs) and battery-only vehicles (BEVs). It is still unclear which type of powertrain will prevail in the future. Therefore, we developed a method to compare different powertrain options based on different scenarios in terms of primary energy consumption, CO2 emissions, and fuel costs. We compared the results with the internal combustion engine vehicle (ICEV). The model includes a model for the climatization of the driver’s cabin, which we used to investigate the impact of autonomous driving on energy consumption. It became clear that certain powertrains offer advantages for certain applications and that sensitivities exist with regard to primary energy and CO2 emissions. Overall, it became clear that electrified powertrains could reduce the CO2 emissions and the primary energy consumption of HDVs. Moreover, autonomous vehicles can save energy in most cases.

Aedes albopictus and Ae. japonicus are two of the most widespread invasive mosquito species that have recently become established in western Europe. Both species are associated with the transmission of a number of serious diseases and are projected to continue their spread in Europe.In the present study, we modelled the habitat suitability for both species under current and future climatic conditions by means of an Ensemble forecasting approach. We additionally compared the modelled MAXENT niches of Ae. albopictus and Ae. japonicus regarding temperature and precipitation requirements.Both species were modelled to find suitable habitat conditions in distinct areas within Europe: Ae. albopictus within the Mediterranean regions in southern Europe, Ae. japonicus within the more temperate regions of central Europe. Only in few regions, suitable habitat conditions were projected to overlap for both species. Whereas Ae. albopictus is projected to be generally promoted by climate change in Europe, the area modelled to be climatically suitable for Ae. japonicus is projected to decrease under climate change. This projection of range reduction under climate change relies on the assumption that Ae. japonicus is not able to adapt to warmer climatic conditions. The modelled MAXENT temperature niches of Ae. japonicus were found to be narrower with an optimum at lower temperatures compared to the niches of Ae. albopictus.Species distribution models identifying areas with high habitat suitability can help improving monitoring programmes for invasive species currently in place. However, as mosquito species are known to be able to adapt to new environmental conditions within the invasion range quickly, niche evolution of invasive mosquito species should be closely followed upon in future studies.

The transformation towards carbon-neutral and circular economies and industrial systems is of utmost importance facing climate change and scarcity of resources. To tackle the resulting enormous planning and implementation tasks, there exist on the one hand very detailed bottom-up process models and roadmaps for specific technologies and companies, and on the other hand highly aggregated top-down approaches and scenarios for climate-neutral trajectories at global, EU and national scale. However, only few approaches so far specifically address the regional application level, which is of high importance for the implementation of car-bon-neutral and circular industrial systems because of the many intersectoral relations between companies and manifold links between material and energy flows within a region. This holds especially for the regional interrelations of energy and material intensive industries like steel, cement, or chemistry. Additionally, regional characteristics will have a strong impact on the design of new pipeline infrastructures for the transportation of hydrogen or CO2. Therefore, regional analyses and integrated approaches for modelling and assessment are required to overcome these gaps methods and applications. Against this background, the aim of this dissertation is to develop integrated modelling, evaluation and planning approaches for the transformation towards carbon-neutral and circular industrial systems and infrastructures with specific emphasis on solutions for the regional level. The dissertation serves to provide transparency on the development of material and energy flows over time, supports technology choice decisions based on techno-economic and environmental evaluations, and supports policy and management decisions on infrastructure and technology investments. The developed approaches have to regard for many requirements and challenges, i.e., approaches need to applicable at regional level, regard for the nexus between carbon neutrality and circular economy, incorporate intersectoral interdependencies between companies and material flows, be interdisciplinary in that they are able to regard for technical, economic, environmental as well as social aspects, consider spatial relations and regional networks, and are dynamic in that they regard for the transformation over time. These requirements and challenges are analysed and integrated via different methodological approaches and system boundaries. The dissertation specifically addresses the transformation of the metals and cement & construction sectors in North Rhine-Westphalia (NRW), a region that accounts for one third of the German cement and chemical production and two fifths of the steel production in Germany. Being a crucial hub for the heavy industries in Eu-rope, the state is responsible for one quarter of the annual GHG emissions in Germany, half of these emissions comes from the energy sector and approximately one fifth is generated by the regional industries. As the state is currently witnessing fundamental structural changes in the industrial sector, it is a suitable region for investigating the transformation process and demonstrating the respective methods. Moreover, the state can also represent the main features of other industrial regions in Germany and Europe. The dissertation consists of five parts. Part I presents the background, structure and region of interest, and dis-cusses the adopted methods and derived approaches. The next three parts (II – IV) encompass the cumulative dissertation. Herein, it is composed of nine peer-reviewed publications that address the two mentioned sectors (i.e. metals and cement & construction) via using different methods and system boundaries. Part II on the metals sector comprises three papers. Paper 1 addresses the industrial transformation in the steel industry by means of developing a hybrid model that defines and quantifies the changes in the regional and energy material flows in North Rhine-Westphalia. Paper 2 determines the causes of CO2 emissions during the production process of cast iron and steel and the mitigation potentials. Paper 3 presents a techno-economic and environmental (TEE) assessment to study the impact of increasing the share of secondary inputs (i.e. steel scrap) from an interdisciplinary perspective. Part III on the cement and construction industry contains four publications. Paper 4 studies the role of CCUS in decarbonizing the cement industry and discusses its necessity as well as the associated challenges. The paper is based on an extensive literature review and analyses the supply chains, the various options that cement producers have to mitigate their emissions and their techno-economic requirements, advantages, drawbacks, boundaries and challenges. Paper 5 aims at promoting a circular economy in the construction sector via presenting a novel model that estimates the regional supply and demand of secondary materials over time. Paper 6 focuses on the spatial aspects of carbonation as a specific CCU technology, and realizes a relationship between the distance and CO2 sequestration capacity in NRW via locational material flow analysis and an optimization model. Paper 7 enhances this analysis by using more data inputs and classifying the available materials into different categories, which results in more detailed analyses and outcomes. Part IV on the intersectoral impacts and infrastructure planning consists of two papers. Paper 8 focuses on the relationship between carbon neutrality and circular economy via an intersectoral energy and material flow analysis in NRW. Herein, a broad system boundary has been defined in order to comprehensively include a wide range of industrial value chains. Paper 9 presents an extensive analysis on the configurations and costs of the prospective CO2 network in Germany. Part V on the Conclusions & Outlook presents the main outcomes of the dissertation, and recommendations for future research activities. Methodologically, the derived approaches and frameworks are based on three fundamental methods A) Mate-rial Flow Analysis (MFA), B) integrated TEE assessment, and C) planning of optimal networks and infrastructures. A) The basic MFA methodology has been extended by integrating dimensions such as time, location, and process modelling. As a result, extended approaches such as regional intersectoral MFA, prospective MFA, locational MFA, and dynamic-locational MFA are developed and applied to practical planning case studies. B) Integrated TEE assessment is applied as a comprehensive approach to merge the relationship between the technical, economic and environmental performance. The derived framework is used to investigate and optimize the three aspects simultaneously. C) Approaches for planning of optimal networks and infrastructure are used to design the prospective infrastructures, specifically the CO2 pipeline network in Germany. Herein, an optimization model has been developed based on an extensive number of datasets and a scenario analysis has been also carried out to illustrate the impacts of different conditions. Overall, this dissertation succeeded in providing innovative modelling extensions and integrations, which have been used to investigate ongoing serious themes and address real industrial questions. The quantitative and qualitative analyses have achieved the dissertation’s goals and fulfilled the identified requirements. The presented case studies on the different industries and materials have demonstrated the effectiveness of the derived frameworks, which can be also used to solve other problems. Therefore, the dissertation is an added value to the academia and of high interest for the industrial sector and policymakers. For researchers, the presented models provide a basis for further studies and research. For the industrial sector and policymakers, the comprehensive analyses and conclusions can be very helpful in deriving regional strategies and roadmaps. Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2023; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme, Karten (2023). doi:10.18154/RWTH-2023-05379 = Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2023 Published by RWTH Aachen University, Aachen

Abstract Whereas temporal variability of plant phenology in response to climate change has already been well studied, the spatial variability of phenology is not well understood. Given that phenological shifts may affect the magnitude of biotic interactions, there is a need to investigate how the variability in environmental factors relates to the spatial variability in herbaceous species’ phenology by at the same time considering their functional traits to predict their general and species-specific responses to future climate change. In this project, we analysed phenology records of 148 herbaceous species, which were observed for a single year by the PhenObs network in 15 botanical gardens. For each species, we characterised the spatial variability in six different phenological stages across gardens. We used boosted regression trees to link these variabilities in phenology to the variability in environmental parameters (temperature, latitude, and local habitat conditions) as well as species traits (seed mass, vegetative height, specific leaf area, and temporal niche) hypothesised to be related to phenology variability. We found that spatial variability in the phenology of herbaceous species was mainly driven by the variability in temperature but also photoperiod was an important driving factor for some phenological stages. In addition, we found that early-flowering and less competitive species indicated by small specific leaf area and vegetative height were more variable in their phenology. Our findings contribute to the field of phenology by showing that besides temperature, photoperiod and functional traits are important to be included when spatial variability of herbaceous species is investigated.

Polycyclic aromatic hydrocarbons (PAHs) represent a large class of persistent organic pollutants in an environment of special concern because they have carcinogenic and mutagenic activity. In this paper, we focus on and discuss the effect of different parameters, for instance, initial concentration of Anthracene, temperature, and light intensity, on the degradation rate. These parameters were adjusted at pH 6.8 in the presence of the semiconductor materials (TiO2) as photocatalysts over UV light. The main product of Anthracene photodegradation is 9,10-Anthraquinone which isidentified and compared with the standard compound by GC-MS. Our results indicate that the optimum conditions for the best rate of degradation are 25 ppm concentration of Anthracene, regulating the reaction vessel at 308.15 K and 2.5 mW/cm2of light intensity at 175 mg/100 mL of titanium dioxide (P25).