Diese Dissertation besteht aus drei Kapiteln, die durch die europäische Schuldenkrise als gemeinsames Thema verbunden sind. Kapitel eins untersucht die Auswirkungen der Finanzintegration auf das Kreditangebot der Banken und die Realwirtschaft. Im Jahr 2007 ersetzt die Europäische Zentralbank die nationalen Sicherheitenlisten durch eine einzige Euroraumliste. Für Banken mit solch neu zugelassene Sicherheiten sinken die Finanzierungskosten. Diese Banken vergeben mehr Kredite, insbesondere an risikoreichere und unproduktivere Firmen in anderen Euroraumländern. Bei diesen Firmen wiederum nehmen Beschäftigung und Investitionen zu. Die Ergebnisse verdeutlichen die unbeabsichtigte Rolle der Finanzintegration beim Anheizen grenzüberschreitender Kreditblasen. Kapitel zwei untersucht die politischen Verbindungen von Bankvorständen in Krisenzeiten. Regierungen beeinflussen nach einer staatlichen Bankenrettung die Zusammensetzung von Bankvorständen, um sich Kontrollrechte zu sichern. Wir stellen fest, dass die Anzahl der politischen Vorstandsmitglieder nach einer staatlichen Unterstützung um 21,4% steigt. Gerettete Banken mit solch neuen politischen Vorständen schneiden in Bezug auf Marktkapitalisierung und Bewertung deutlich besser ab als gerettete Banken ohne solche Verbindungen. Kapitel drei liefert kausale Belege für die Auswirkungen von Kreditklemmen auf politische Radikalisierung. Mit Daten zu Bank-Firmen-Verbindungen und kommunalen Wahlergebnissen zeigen wir, dass Unternehmen mit einer Beziehung zu schwachen Banken einen Rückgang ihres Kreditangebots und des Beschäftigungswachstums erleben. Anschließend schätzen wir die Auswirkungen der Arbeitslosigkeit auf das Wahlverhalten. Wir konstruieren ein Instrument für die Arbeitslosigkeit, das auf der Abhängigkeit gegenüber schwachen ausländischen Banken auf kommunaler Ebene basiert. Ein Anstieg der instrumentierten Arbeitslosigkeit führt zu einer Steigerung der Wählerradikalisierung um 7 Prozentpunkte. / This thesis consists of three chapters linked by the European Debt Crisis as their common theme. Chapter One studies the effect of financial integration on bank credit supply and the real economy. In 2007, the European Central Bank replaces national collateral lists with a single euro area list. Banks holding newly eligible assets experience a reduction in their cost of funding.These banks lend more, especially to riskier and less productive borrowers located in other euro area countries. The borrowers in turn experience growth in employment and investment. The results highlight the unintended role of financial integration in fueling crossborder credit booms. Chapter Two investigates the political ties of too-big-to-fail bank boards in crisis times. After a bailout, governments are likely to influence bank board compositions to secure control rights. Combining two novel datasets on political ties of banks and state aid in the European Union, we find that the number of politically connected board members increases by 21.4% following government support. Bailed-out banks with such new political ties perform better in terms of market capitalisation and valuation than bailed-out banks without such ties. Chapter Three provides causal evidence on the effect of credit crunches on political radicalisation. We combine data on bank-firm connections and electoral outcomes at the city-level during the 2008-2014 Spanish Financial Crisis. First, we show that firms in a relationship with weak banks experience a reduction in their loan supply and employment growth. Next, we estimate the effects of unemployment on voting behaviour. We construct an instrument for unemployment based on the city-level exposure to foreign weak banks. We find that a one standard deviation increase in instrumented unemployment translates into a 7 percentage point increase in the radicalisation of voters.

There is an increasing understanding of the influence seabirds have on island food webs globally, which often arises from the trans-boundary input of nutrients. Seabird-derived nutrients, primarily in the form of guano, can have significant effects on island communities by increasing primary productivity and then indirectly influencing other species. However, there are few studies looking at how the influence of seabirds permeates island food webs to higher trophic levels, in particular within the United Kingdom, which holds globally significant populations of seabirds. To understand the extent to which seabirds influence islands, the size of the seabird population must be first reliably determined. With an increasing seabird population size and density the effects of seabirds on land increases concomitantly. The Atlantic puffin Fratercula arctica is a difficult species to reliably monitor, given its underground presence from the use of burrows and its notoriously erratic attendance at colonies. This study looks firstly at a novel method to monitor the Atlantic puffin using time-lapse photography. Time-lapse photography provides a way to derive an estimate of population size from counts of individuals, by repeated photographs across a period of time with relatively low cost and from areas normally considered inaccessible. The results showed there was a significant and positive relationship between the maximum numbers of Atlantic puffins observed and the size of the population; further work is required though to reduce the error associated with population size estimates. Data from high temporal resolution time-lapse photography shows how the attendance of Atlantic puffins at the colony varies over different temporal scales. Given the variability in sampling intensity the study stresses the need for standardised sampling intensity with the use of photography to monitor Atlantic puffins. Secondly, this study showed how the presence of two seabird species, the Atlantic puffin and the great skua Stercorarius skua, alters island food webs. These seabird species are likely to change plant community diversity, relative to areas without seabirds. The chemical concentration of grasses inside seabird colonies was also altered: grasses had significantly higher concentrations of nitrogen and also had higher values of δ15N, relative to areas without seabirds. These chemical alterations suggest that nutrients from seabirds are incorporated into local vegetation. Furthermore, samples of hair from rabbits and sheep found within puffin colonies also had significantly higher values of δ15N, suggesting that nutrients travel from seabirds into secondary consumers, via ornithogenic forage. An additional study on the transfer of nutrients within island food webs showed how ornithogenic nutrients deposited on an island in the Baltic Sea were incorporated into house martins, via aquatic insects. These studies, along with an understanding of seabird population size, suggest that the impact of seabirds on island food webs may be considerable and have large consequences for island conservation and management.

Interactions between above ground and root-feeding herbivores can be influenced by changes in plant traits, such as tissue chemistry and morphology. Environmental heterogeneity and perturbations also affect these plant-mediated interactions. Climate change is a multi-faceted phenomenon; increases in atmospheric carbon dioxide (CO2) concentrations lead to increased global mean temperature and an associated higher frequency of extreme weather events. These factors can potentially perturb ecosystem function by altering both plant–herbivore and herbivore–herbivore interactions. A detailed understanding of whether above–belowground interactions are affected by climate change remains lacking. In an attempt to fill knowledge gaps in this understudied area of ecology, this thesis investigates, through a series of glasshouse experiments, the effects of elevated CO2 and other aspects of climate change, such as altered phenology, on the interspecific interaction between the aboveground large raspberry aphid (Amphorophora idaei) and the root feeding larvae of the vine weevil (Otiorhynchus sulcatus), mediated by the shared raspberry (Rubus idaeus) host-plant. Under ambient climate conditions, reciprocal feeding facilitation was observed to occur between aphids and vine weevil larvae feeding on raspberry, with the presence of one increasing the abundance of the other herbivore, and vice versa. This occurred regardless of plant cultivar and order of herbivore arrival on the plant. It is likely that this facilitative relationship is driven by over-compensatory plant growth in response to herbivory. Although tougher, adult vine weevils show a feeding preference for leaves grown in elevated CO2. Herbivory may be more influential than CO2 in determining plant–herbivore interaction outcomes. Aphids affect plant intraspecific competition to a greater extent than elevated CO2 by altering plant biomass of both infested and non-infested plants. In conclusion, this particular plant–herbivore system would seem to be relatively robust in the face of possible future CO2 concentration scenarios.

Wheat yields need to rise to meet growing demands due to population growth and changing diets. Additionally, the resilience of crop yields to climate change and rising temperatures needs to be improved. Inhibition of photosynthesis under sub-optimal environmental conditions decreases carbon fixation, reducing crop yields. Heat stress inhibits photosynthesis, in part due to a decrease in the activation state of Rubisco. Rubisco activase (Rca) is required to restore and maintain the catalytic activity of Rubisco. Rca has a relatively low temperature optimum; improving its thermal tolerance would maintain Rubisco activity and enhance photosynthesis at higher temperatures, with predicted positive impacts on grain yields under moderate heat stress. Two approaches were taken to improve the thermal tolerance of Rca in wheat. Firstly, natural variation in the thermal tolerance of Rca in wheat was investigated. Cultivars exhibiting differences in their photosynthetic performance were identified, but the complexity in breeding for increased thermal tolerance was highlighted, with both advantageous and disadvantageous characteristics being identified. The second approach was to introduce the more thermally stable Rca from cotton into wheat in an attempt to broaden the range of temperatures at which photosynthesis operates. Transgenic plants were produced but the cotton Rca protein was undetectable in the wheat lines investigated. Two genes encoding Rca in wheat were identified; one gene is alternatively spliced to produce α and β isoforms. Virus-Induced Gene Silencing of the Rca isoforms in wheat indicated that the Rca genes in wheat may be co-regulated. A non-radioactive activity assay was developed for use in Rubisco and Rca research, allowing high-throughput of samples and avoiding the difficulties some labs may have in completing radioactive assays. The information gained in this study will guide future approaches to optimise the thermal stability of Rca and generate temperature-resilient crops.

Plants as sessile organisms have adapted highly sophisticated cellular processes to cope with environmental stress conditions, which include the initiation of complex transcriptional regulatory circuits. The heat shock transcription factors (HSFs) have been shown to be central regulators of plant responses to abiotic and biotic stress conditions. However, the extremely high multiplicity in plant HSF families compared to those of other kingdoms and their unique expression patterns and structures suggest that some of them might have evolved to become major regulators of other non-stress related processes. Arabidopsis thaliana HSFA1b (AtHSFA1b) has been shown to be a major regulator of various forms of plant responses to abiotic and biotic stresses. However, it has also been suggested that overexpression of AtHSFA1b results in a subtle developmental effect in Arabidopsis thaliana and Brassica napus in the form of increased seed yield and harvest index. Through genome-wide mapping of the AtHSFA1b binding profile in the Arabidopsis thaliana genome, monitoring changes in the AtHSFA1b-regulated-transcriptome, and functional analysis of AtHSFA1b in Saccharomyces cerevisiae under non-stress and heat stress conditions, this study provides evidence of the association of AtHSFA1b with plant general developmental processes. Furthermore, the outcome of this research shows that AtHSFA1b controls a transcriptional regulatory network operating in a hierarchical manner. However, in an agreement with a previously suggested model, the results from this study demonstrate that the involvement of AtHSFA1b in the regulation of heat stress response in Arabidopsis thaliana is possibly limited to the immediate and very early phases of heat stress response which also results in a collapse in its transcriptional network which seems to be accompanied by a general shutdown in plant growth and development.

This PhD thesis seeks to consider conifer forestry stream corridor design in relation to both in-stream and riparian zone biodiversity and functioning. The contribution, availability and source of basal resources within varying corridor conditions are the focus of this project. This approach is combined with surveys of community diversity on a number of key trophic scales in order to determine how the corridor characteristics and their associated resource availability, affects community structure. The effects of varying design and management of the riparian buffer zones within afforested stream systems on in-stream and overall habitat diversity and functioning remains largely unknown. Although guidelines have been implemented for several years (Forest and Water Guidelines, Forestry Commission), recommendations, although based on sound assumptions, are subjective assessments and tend not based on scientific research or data. As such, the premise of this project is to consider a variety of corridor physical parameters adjacent to low-order streams within two afforested catchments in South-West Scotland, between 2003 and 2005, in order to contribute to the understanding of system functioning within the limitations of forestry land-use and management. A number of different approaches were employed in order to define the proportional contributions of allochthonous and autochthonous material within the benthos of the stream systems. This was done in order to define resource availability, biofilm characteristics, stream functioning and the role of corridor design in influencing resource availability. Yet, despite significant autochthonous productivity, allochthonous organic matter was the primary resource utilised by many taxa. However, conversely, light regime was found to be fundamental in shaping production and community structure within these ecosystems. Consequently, here I explore a number of different trophic scale responses to riparian conditions in order to define the biotic responses to variation of resource availability, with the aim of contributing information which may aid in design and management of afforested riparian zones.

Stomatins belong to the band-7 (or SPFH domain) family (short for Stomatin, Prohibitin, Flotillin HflC/K) of diverse membrane proteins. This protein family is evolutionary conserved with members found in all sequenced eukaryotes and in most prokaryotes. Band-7 family proteins have the ability to oligomerise and generally aid in the assembly and regulation of large membrane-bound protein complexes. In animals, stomatins have been demonstrated to regulate ion channels by direct protein interactions. Additionally, they localise to membrane microdomains where they actively contribute to their assembly by binding sterols, and they also associate with the actin cytoskeleton. The Arabidopsis genome encodes for two structurally similar stomatin-like proteins that are functionally completely unknown yet. They will be referred to as AtSlp1 (for Arabidopsis thaliana stomatin-like protein) and AtSlp2. The aim of this thesis was to provide a detailed characterisation of these two genes on a molecular and functional level. Both proteins are expressed ubiquitously throughout plant development, but they accumulate at particularly high levels in pollen and other metabolically active cells. Phylogenetic analysis reveals that AtSlps are homologous to stomatin-like proteins of type 2. Amongst these, the human stomatin-like protein 2 (HsSlp2) is localised to mitochondria where it participates in large membrane-bound protein complexes and is also involved in the proliferation of cancer cells. Evidence is provided here that demonstrates mitochondrial localisation of both Arabidopsis Slp proteins in vitro and in vivo. On a functional level, mitochondria from an slp1 knockout mutant plant have a decreased mitochondrial membrane potential and increased oxygen consumption rates. This is interpreted as a defect in coupling efficiency and an impairment of the mitochondrial inner membrane integrity. This defect results in a variety of other growth phenotypes that are related to metabolically active tissues and cell types. Knockout plants are delayed in overall growth of shoots and roots and have decreased seed germination rates. Additionally, these plants are less resistant to conditions of high salinity and are less fertile. Overexpression of a protein acting as a putative dominant-negative Slp fragment results in plants with a dwarf phenotype and early onset of leaf senescence. This phenotype correlates with increased levels of reactive oxygen species and altered organelle ultrastructure. Guard cells from these plants in particular have enlarged chloroplasts and are impaired in transpirational control. It is concluded that also in plants, stomatins act together with other band-7 family proteins as parts of large protein complexes that have regulatory roles important for development and stress responses. Their main role is probably to provide membrane scaffolds that affect mitochondrial function and morphology during cell division and in situations of mitochondrial stress.

Plants can vary in their mating systems from completely inbreeding to completely outcrossing, with intermediate forms referred to as mixed mating systems. Arabidopsis lyrata is a strongly outcrossing perennial due to a sporophytic self incompatibility (SI) system. The species occurs in temperate regions of the Northern hemisphere where in Europe its SI system is fully working but around the Great Lakes of North America some populations of A. lyrata show a breakdown in SI. Consequently these North American populations are inbreeding or have a mixed mating system next to outcrossing populations with a working SI system. In this thesis I used North American A. lyrata to investigate the evolutionary consequences involving variation in mating systems. First of all I was interested in the time that populations had been isolated from each other in the past that could explain differences in mating systems. In order to determine whether populations experienced a breakdown of SI independently or whether this originated from a single event I used chloroplast DNA (cpDNA) markers to reveal deep phylogeny and microsatellite markers to determine recent population genetic patterns. The results showed a loss of SI in populations from all three detected cpDNA haplotypes. Microsatellite data showed that predominantly inbreeding populations sharing one of these haplotypes showed high levels of homozygosity and that in all three haplotype lineages self-compatible individuals always had reduced heterozygosity compared to self-incompatible individuals. The data further showed that there had likely been at least two independent postglacial colonization routes to the north of the great lakes. This was consistent with phylogeographic studies of other organisms with limited dispersal such as reptiles and amphibians. The next question was the role of inbreeding depression in the loss of SI. Inbreeding depression is defined as the decline of fitness after an inbreeding event. Inbreeding causes an increase in homozygosity that exposes recessive deleterious mutations, which would normally be sheltered in a heterozygous state, and causes a fitness decline. Individuals experiencing a loss of SI will have higher inbreeding levels and can result in inbreeding depression, which is thought to maintain the SI system. To gain more insight into the role of inbreeding depression in the shift from self-incompatibility to self-compatibility, I conducted an experiment in which I created outcrossed and selfed offspring from self-compatible and self-incompatible mothers from populations with different outcrossing histories. I monitored the offspring for early- and late acting fitness traits like germination rate, growth and time to flowering. I found inbreeding depression in only one late acting fitness trait, the increase in leaves 5 weeks after germination, to be significantly higher for self-incompatible than self-compatible individuals. I also conducted a regression analysis where relative fitness (the ratio of the fitness trait values of selfed and outcrossed offspring) per mother was regressed against population heterozygosity and found a significantly negative regression. This result suggested that individuals from a population with a relatively high heterozygosity suffered more from inbreeding depression than individuals from populations with a relatively low heterozygosity. This indicated that the history of outcrossing of a population, or purging, played an important role in the shift from outcrossing to inbreeding. The detection of inbreeding depression could not be evident by only looking at life history traits under greenhouse conditions. But stressful environmental conditions like a pathogen infection could magnify inbreeding depression. I would expect that predominantly outcrossing populations would have a higher heterozygosity than predominantly inbreeding populations and therefore be able to show a higher fitness when exposed to a pathogen. To test this hypothesis I used four outcrossing and four inbreeding populations, which I infected with the crucifer pathogen Albugo candida and measured relative growth rates (RGR) and monitored resistance rates. The results showed that there were three infection phenotypes: resistant (no signs of infection), partially resistant (only the initially infected parts showed symptoms) and susceptible (symptoms present on the whole plant). The inbreeding populations showed a bimodal distribution of resistance as two populations showed a high rate of resistance and two showed a low rate of resistance. The outcrossing populations showed a much more uniform distribution of resistant individuals with a higher rate of partially infected individuals across populations than inbreeding populations. Resistant and partially resistant individuals did not differ significantly in their RGR from each other but both had a significantly lower RGR than the untreated control group and a significantly higher RGR than the susceptible individuals. This suggested a cost of resistance that was lower than a cost of being susceptible in the presence of a pathogen. There was no effect of mating system on RGR, which was primarily caused by the fact that two inbreeding populations contained a high amount of resistant individuals and an outcrossing population that showed a very low amount of partially resistant and resistant individuals. The difference in resistance to A. candida in A. lyrata differed much more between inbreeding than between outcrossing populations. This suggested that alleles responsible for resistance were concentrated in homozygous form in inbreeding populations and both homozygous and heterozygous form in outcrossing populations. This would mean that mating system plays a role in susceptibility, as resistance genes would be concentrated in certain individuals in inbreeding populations as opposed to a more modal distribution in outcrossing populations. A shift in mating system often has an effect on floral traits, as there is a lack of necessity to attract pollinators. I wanted to test whether these changes were apparent in A. lyrata by comparing pollinator attractants and sexual floral traits between strongly outcrossing and strongly inbreeding populations. I hypothesized that individuals depending on pollinators for outcrossing would show a higher emission of volatiles and floral traits that had evolved to optimize pollen transmission to conspecifics. Autonomously selfing individuals would be independent of pollinators so should show a reduced volatile emission pattern, a floral trait composition that evolved to transmit pollen to their own stigma, and a reduction in floral display compared to outcrossers. My results showed a somewhat contradicting pattern as self-compatible individuals showed higher volatile emission than self-incompatible individuals but self-incompatible individuals showed larger petal size than self-compatible individuals. Pistil height and stamen length were strongly correlated but petal size seemed to co-vary relatively independent from pistil and stamen length. I found no effect of mating system on the evolvement of floral traits to optimize pollen to the stigma and contradicting patterns for pollinator attractant traits. Due to low sample sizes this study turned out to be a pilot study for further research so the results in this study were not conclusive at this stage. Finally I conclude that SI has been lost independently several times and the low observed genetic load in the North American populations compared to the European populations could be responsible for that. There have probably been two independent colonization routes to the North of the Great Lakes following the last glaciation in which a Northern distributed cpDNA haplotype lineage seems to have a lower frequency of SC individuals than a southern cpDNA haplotype lineage.

Stress causes crops to grow below their potential and this affects the vitality and physiological functioning of the plants at all levels leading to reduction in yield. Remote sensing of vegetation is regarded as a valuable tool for the detection and discrimination of stress, especially over large or sensitive regions. The main aim of the research carried out is to assess the potential of remote sensing to detect CO2 leakage from CCS repositories. Further to this, the capability of remote sensing to discriminate between stresses with similar mode of action is explored. Two stress factors were selected for study: (1) elevated concentrations of soil CO2 in the plant root zone and; (2) herbicide, applied at sub-lethal levels. To understand the effects of soil CO2 and herbicide stress on vegetation reflectance, field experiments were carried out on maize (2009) and barley (2010) to investigate the effects of elevated soil CO2 concentrations and of different levels of herbicide treatments on vegetation growth and canopy reflectance using hyperspectral remote sensing techniques. The findings from this study shows that the average canopy reflectance response of maize and barley to CO2 and herbicide stress were increased reflectance in the visible and decrease in near infra-red region as well as changes in the position and shape of the red-edge. The red-edge first-derivative for barley treated with CO2 were composed of maximum peaks between 716 and 730nm and smaller peaks at 699 and 759nm, the control had peaks at 727 and 730 nm, with similar smaller peaks. Barley treated with herbicide had early peaks (a day after treatment) at 697, 715 and 717nm with a shoulder at 759nm, as the experiment progressed (16 days after treatment) the stress became apparent and the peak remained stationary at 730nm, the magnitude decreased to 712nm at late treatment period (35 days after treatment). The control had single peak at 726nm. CO2 treated maize had double peaks at 718 and 730nm, with secondary peaks at 707 and 794nm. Maize treated with herbicide had maximum peaks at 716 and 723nm, with the shoulder at 759 nm; the peaks were similar with the control plots but decreased in magnitude. The main differences between the treatments were in the shape and positions of the peaks that identify the red-edge. The canopy reflectances of the plants were further analysed using the blue (400-550nm) and red (550-750nm). In these regions the main feature of concern is chlorophyll content. The analysis showed that the band depths of controls plants were deeper compared to the stressed plants which is dependent on the stress and crop type. Other vegetation indices used in this study were the Chlorophyll Normalized Difference Index (Chl NDI), the Pigment Specific Simple Ratio for chlorophyll a and b (PSSRa and PSSRb) and the Physiological Reflectance Index (PRI). The results show that they were promising indicators of early stress detection, some indices performed better than others depending on the stress type, species and duration of stress. Chl NDI was sensitive to high soil CO2 concentration in maize and barley, sub-lethal herbicide treatment at 10% - 40% level in barley and was insensitive to both low CO2 in the barley and maize as well as 10% herbicide treatment in maize. PSSRa was a good indicator of early CO2 stress in maize and high CO2 in barley as well as 10- 40% herbicide treatments. PSSRb could detect high CO2 level in maize and barley and all levels (5-40%) of herbicide treatments. PRI was insensitive to 5% herbicide treatment in barley but sensitive to high CO2 in maize at early stage of the experiment. This study has demonstrated that remote sensing approach could be deployed for discriminating between different stressors using their red-edge first-derivative peaks, band depths and vegetation indices.

Marianne North was a major figure within the history of nineteenth-century botanical illustration. She produced a substantial body of botanical paintings as the result of extensive travels to many different parts of the world and was responsible for the founding of a major purpose-built gallery containing a representative collection of her work which still stands today in the Royal Botanical Gardens at Kew. Despite North's percieved importance as a botanical painter, relatively little of any critical/analytical substance has been written about her life and work from an art-historical or scientific perspective. North's place within nineteenth-century visual culture is arguably a contested one, despite having been a major contributor to nineteenth-century botanical painting. North's work therefore remains problematic to both botanists and art historians because it does not conform wholly to the established nineteenth century conventions of either scientific-botanical illustration or art. This thesis will explore the uncertain positioning of North's painting through a close analysis of its relationship to nineteenth and twentieth-century visual practices. In light of this analysis, it will be argued that North's painting does not successfully combine artistic and scientific perspectives, as some have argued, but instead presents an unidentifiable mode of visual representation that shifts uncertainly between art and science, thereby deconstructing any categorical distinction between the two.