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The existence of the common ash (Fraxinus excelsior L.) is acutely threatened by ash dieback, caused by the fungus Hymenoscyphus fraxineus. The disease may lead to reduced pollen flow due to crown damage and tree mortality, which affects the reproductive ecology of Fraxinus excelsior L. However, sexual reproduction in forest trees plays an essential role not only in species conservation and adaptive potential, but also in natural selection and the promotion of genetic diversity. The impending risk of reduced gene flow is therefore of serious concern and threatens the conservation of this valuable tree species. Therefore, it is critical to advance research on the effects of ash dieback on (effective) pollen transport and reproductive ecology of Fraxinus excelsior L. These results can be used to support forest management, such as maintaining ash genetic diversity and promoting the development of natural resistance. Therefore, this study will conduct extensive research in two seed orchards and one floodplain forest in Southern Germany from 2018 to 2021. The main objective of this dissertation was to improve our understanding of gene flow patterns by investigating (effective) pollen dispersal, pollen production and pollen and seed quality of ash trees in relation to their health status.
The main research questions were:
(1) How does ash (effective) pollen transport vary with stand density, ash abundance and meteorology?
(2) Is there a link between mating success and damage to the paternal tree?
(3) Does the health of the ash trees affect pollen and seed quality, as well as pollen quantity?
To answer these questions, different methods were used in the study areas, which differed in topography and degree of stocking. Therefore, not all parameters were examined at every site and in every year, depending on the issue concerned. The health status of the ash trees was assessed every year in July using a six-level vitality score. In addition, phenological observations were made annually in spring according to the BBCH code to determine different phenological stages such as beginning of flowering, full flowering, flower wilting and end of flowering.
Aerobiological pollen measurements were carried out in the two orchards in 2019 and 2020 using self-constructed gravimetric pollen traps of the Durham type. One of the traps was placed in the center of each orchard and up to five additional traps were placed at a maximum distance of 500 m from the orchard. Five vaseline-coated slides were attached to each trap (one in each cardinal di-rection and one horizontally) to measure pollen transport (N=4) and weekly cumulative pollen position (N=1). To study the influence of meteorological parameters, a climate station was placed in each orchard. In addition, other anemometers or data loggers for air temperature and relative humidity were installed.
For paternity analyses, cambium samples were collected for genotyping from branches and stumps of 251 ash trees in a seed orchard and floodplain forest. In addition, seeds were collected from 12 parent trees per site with different health status. Genetic analyses were performed to determine paternal trees using nuclear microsatellites. Paternities were assigned using the likelihood model implemented in Cervus 3.0.7 software.
Pollen viability of ash trees with different health status were studied at all three sites. Pollen production in the two seed orchards and seed quality in one orchard and the floodplain forest. For this purpose, inflorescences of 105 ash trees (pollen production), pollen of 125 ash trees (pollen viability) and seeds of 53 ash trees (seed quality) were collected. Pollen production was estimated from flower to tree level and pollen viability was determined using the TTC (2,3,5-triphenyltetrazolium chloride) test. In addition, pollen storage experiments were carried out to investigate the influence of meteorological factors on pollen viability. Pollen were stored for various periods at different temperatures and humidity conditions and their viability was determined. Seeds were analyzed for quantity and quality (solid, hollow grains, insect damage and germination) and seed quality was determined by both stratification and the TTC test.
The results on aerobiological pollen transport showed that pollen transport is related to meteorology, phenological development and the topography of the study site. The Schorndorf orchard, located on a slope, showed higher pollen levels at the downslope traps, likely due to the transport of pollen by cold air flow. The prevailing wind direction often corresponded with the compass direction in which the highest pollen deposition was measured. When analyzing the pollen data for individual traps, the highest pollen levels were measured outside the orchards in 2019, a year with low flower development. In contrast, most pollen were collected inside the orchard in the pollen-rich year 2020. This suggests that trees outside the orchard can potentially contribute more to pollination in a poor pollen year. In Emmendingen, minor difference in pollen quantity was found between traps at 1.5 m and 5 m height, but there were temporal differences indicating vertical variation in pollen availability. Ash pollen were found to be transported over a distance of more than 400 m, with the amount of pollen decreasing with increasing distance. About 50 % less pollen were measured at a distance of 200 m, but even at a distance of 500 m more than 10 % pollen were still detected.
The studies on effective pollen transport showed similar results: the average distance between father and mother tree was 76 m in the orchard and 166 m in the floodplain forest, with pollination success decreasing considerably with increasing distance. Despite the dense tree cover, the longest distances (> 550 m) were recorded in the floodplain forest. Based on this and the fact that 66.5 % cross-pollen input was recorded in the seed orchard, it can be assumed that pollination does not only involve local sources. However, self-pollination generally did not have a substantial effect on ash reproduction. In terms of health status, both healthy and slightly damaged parent trees showed similar mating success. However, in severely damaged trees almost no flowering could be documented. In general, it was demonstrated that both healthy and slightly diseased fathers sired more offspring than severely diseased ash trees.
The effect of ash dieback on pollen production showed no significant difference between healthy and diseased ash trees, although 53 % of severely diseased male ash trees did not produce flowers. In terms of pollen viability, there was a tendency for diseased ash trees to have less viable pollen than healthy ash trees. In addition, the viability experiments revealed a strong influence of prevailing temperatures on pollen viability, which decreased more rapidly under warmer conditions. There was also no statistical difference in seed quality between ash trees of different health status. However, non-viable seeds were often heavily infested with insects.
In summary, the studies show that a variety of factors influence the reproductive ecology and (effective) pollen transport of ash trees. However, the fact that severely affected ash trees are linked to a reduced flower production and lower pollen quality suggests that as health deteriorates, reproductive capacity also declines. It is therefore likely that severely diseased ash trees have a limited ability to pass on their genes to the next generation. Paternity analyses also suggest that high vigor has a positive effect on reproductive success and that pollen transport can occur over long distances. As susceptibility to ash dieback can be passed on from parents to offspring, these reactions to ash dieback may make ash populations less susceptible in the future.
Finance without foundations
(2022)
This thesis examines the role of financial inclusion by way of access to formal financial services such as savings, credit, transfers and payments, in supporting the lives of refugees in protracted displacement in Jordan. It asks if such access enables smoother financial and livelihood transitions as refugees arrive and integrate into their new environments in host countries. It critically evaluates the narrative presented by humanitarian actors supporting financial inclusion as a marketled intervention to support refugee self-reliance. It argues that the limited provision of financial services through mobile wallets and micro-credit is not sufficient to financially integrate refugees. Above all, it demonstrates through the in-depth qualitative research in Jordan that in a context where refugees’ livelihoods are constrained due to a lack of foundational economic rights, financial services can only marginally improve their lives by making it more convenient to receive remittances and humanitarian transfers.
The research is embedded in a larger project called “Finance in Displacement: Exploring and strengthening financial lives of forcibly displaced persons” (FIND), which was initiated in 2019 as a collaboration between the Katholische Universität Eichstätt-Ingolstadt, the Tufts University, and the International Rescue Committee. The project was supported by the German Federal Ministry for Economic Cooperation and Development (BMZ).
Background:
Pollen allergies are widespread around the world, making the study of pollen levels in and around cities a task of high importance. This is also related to the fact that an increasing number of people is living in cities and urban areas are expanding. In addition, environmental changes in the context of climate change are expected to alter plant characteristics that affect the amount of pollen in the air. In order to assess the allergy risk, information on pollen that people are exposed to is needed. Monitoring of aeroallergens in cities is often conducted using a single trap. This trap can provide information on background pollen concentration, however, it does not reflect temporal and spatial variations of pollen at street level of the heterogeneous urban environment. The amount of pollen in the air is the result of a number of processes, one of which is pollen production. Pollen production is expected to be altered by climate change and is influenced by environmental factors such as temperature or air pollutants. To further investigate variations of allergenic pollen in cities, this thesis focuses on these central research questions:
- Are there differences in the amount of airborne pollen between urban and rural locations and do pollen loads vary at different spatial and temporal scales?
- What is the influence of land use and management on pollen loads?
- Is there a difference in pollen production of allergenic species between urban and rural locations and can the influence of environmental factors be detected?
Data and Methods:
Data on airborne pollen were gathered in two study areas with various pollen traps. In Ingolstadt, Germany, background pollen concentrations of Poaceae were measured in 2019 and 2020. Additionally, a network consisting of twelve gravimetric pollen traps was set up during the grass pollen seasons of those years. For an additional sampling campaign, portable volumetric traps were used to measure pollen concentration at street level. Investigations were also conducted in Sydney, Australia, where concentrations of Poaceae, Myrtaceae and Cupressaceae pollen and Alternaria spores were measured during three pollen seasons from 2017 to 2020. In the summer of 2019/2020, additional ten gravimetric traps were set up. For both study areas, pollen season characteristics and temporal and spatial variations of pollen concentrations and pollen deposition were analysed in context with land use, land management and meteorological parameters.
Furthermore, pollen production of the allergenic species Betula pendula, Plantago lanceolata and Dactylis glomerata was investigated in the Ingolstadt study area along an urbanisation gradient, which covered different types of land use. In total, 24 individuals of B. pendula, 82 individuals of P. lanceolata and 54 individuals of D. glomerata were analysed. Pollen production was compared between urban and rural locations and the influence of air temperature and the air pollutants nitrogen dioxide (NO2) and ozone (O3) was assessed. Air temperature was measured in the field and pollutant concentrations were computed using a land use regression model.
Results and Discussion:
In Ingolstadt, grass pollen concentrations and deposition were generally higher at rural than at urban locations as documented in peak values and seasonal totals. Diurnal variations however, did not vary between urban and rural locations. Grass pollen levels were linked to local vegetation and land use but also land management, as grass cutting was reducing pollen levels in the surroundings.
In Sydney, pollen season characteristics varied between the seasons and we found significant correlations between daily pollen and spore concentrations and meteorological parameters. There were significant positive correlations with air temperature for all analysed pollen and spore types. Correlations with humidity (Myrtaceae, Cupressaceae, Alternaria) and precipitation (Myrtaceae, Cupressaceae) were negative. Spatial variations of pollen deposition were observed, but there were no correlations with land use. This could be attributable to the drought before and during this sampling campaign as well as the temporal setting of the sampling campaign.
The results from both study areas suggest that local vegetation is the main influence on the pollen amount at street level. However, when the season’s intensity decreased, other influences such as resuspension or pollen transport become more important. Analyses of pollen production revealed statistically significant differences between urban and rural locations for B. pendula and P. lanceolata. Pollen production decreased with temperature and urbanisation for all species, however, pollen production varied at small spatial distances within species. For increasing air pollutant levels, decreases were observed for B. pendula and P. lanceolata, but increases for D. glomerata. These results suggest that environmental influences seem to be species-specific.
The results from the studies contribute to the knowledge on temporal and spatial variations of airborne pollen in cities, as well as on pollen production of allergenic species. They highlight the importance of pollen monitoring at street level and at different locations in cities to assess the amount of pollen that people are exposed to. Further research in this area should investigate the influence of land management, which was identified to influence the amount of pollen in the air, and which could be a mitigation strategy for allergy-affected people. In addition, pollen production should be further examined with different kinds of experiments, as it is the major influence of ambient pollen concentration in the air.
Linear regression models are very popular among users as they allow an intuitive interpretation of the dependencies between an outcome variable and explanatory variables. However, to avoid false conclusions from such models, any statistical inference should be backed up by a goodness-of-fit test. These tests check whether the hypothesised class of possible regression functions has been adequately chosen.
In this work, goodness-of-fit tests for univariate linear regression models based on the asymptotic distribution of residual CUSUM processes are studied. In the literature, a distinction is made between random designs and fixed designs when studying such goodness-of-fit tests. We prove that for each of these two scenarios (random and fixed design) there is a corresponding uniform design, we examine similarities and differences between these two scenarios, and prove that, when it comes to goodness-of-fit tests in in linear regression models based on the asymptotic distribution of residual CUSUM processes, one can assume without loss of generality a generic linear regression model.
Furthermore, a geometric interpretation of residual CUSUM limit processes as projections on certain reproducing kernel Hilbert spaces is given, the effect of heteroscedastic regression errors on residual CUSUM limit processes is investigated, and an interpretation of the Khmaladze maratingale transformation as a continuous-time recursive least squares method is made explicit.
Glacier retreat due to climate change is significant and well investigated on a
regional scale. Much less is known about local effects, especially in the proglacial
area. This thesis focuses on glacial changes and new methods to tackle the processes
therein. The glacial changes within the catchment of the river Fagge, in the upper
Kaunertal valley, are investigated by combining different direct glaciological, geodetic
and geophysical methods. Alongside long-term monitoring of glacier flow velocities
at adjacent glaciers, the investigation focuses on the glacier tongue of Gepatschferner.
In addition to the direct measurements of the ice motion and the determination of the
surface mass balance, the ice thickness and the thickness of subglacial sediments is
measured with vibroseismic soundings. Changes in total area, elevation and volume
are calculated from multiple high-resolution digital elevation models from airborne
laser scans. These detailed glaciological investigations are part of the joint project
PROSA, which focuses on the geomorphodynamics of the entire proglacial system
and aims at balancing the sediment budget therein.
The presented cumulative doctoral thesis consists of three publications and additional
results from the glaciological part of PROSA. This includes long-term
monitoring of glacier flow velocities (Paper 1), detailed investigations of the process
development of a surface depression at the tongue of Gepatschferner (Paper 2), and
an approach at closing the balances of ice, water and sediments on the glacier tongue
(Paper 3).
It turned out that the formation of circular and funnel-shaped surface depressions
occurs as a consequence of increased glacier retreat rates. Additionally, the process
of the depression development in turn increases the retreat rates. This exemplary
development was caused by the evacuation of subglacial sediments after a heavy
precipitation event and by decreasing glacier dynamics as a result of negative glacier
mass balances. Beside the mass balances, the horizontal motion and especially the
vertical motion of the glacier provide valuable information on the glacier state, such
as measured in the long-term program on Kesselwandferner. The magnitudes of the
mass exchanges showed the influence of extreme events, which exceed mean daily
and even annual turnovers, as well as the role of the melt water production at the
glacier tongue of Gepatschferner and its severe effect on the glacial runoff regime of
the river Fagge.
This case study aims to identify, inventory and classify existing and potential tourism resources in Iraq al-Amir and its surrounding areas, which could be used as baseline data by decision-makers for future tourism development to develop, promote, and market the area. Additionally, it uses evaluation criteria to identify potential tourism resources, in order to determine suitability and likelihood of success if development does take place. Three distinct tourism segments are considered: cultural heritage, nature-based, and agritourism.
Study findings are primarily based on qualitative methodology, in the form of interviews and field observations. Quantitative methodology was used to extract some of the data from maps of the case study area, as data for some of the criteria was not provided by the respondents. Analysis of the data confirms that Iraq al-Amir and its surrounding areas have abundant potential tourism resources for all three of the tourism segments analysed, particularly in terms of diversification.
Findings reveal that the case study area has inadequate basic infrastructure. A major drawback to the feasibility of future tourism activities is the lack of easy access. The main access road is narrow and very winding, but it would be possible for visitors to use three existing alternative roads to access the area if they were upgraded and signposted. The lack of infrastructure is a direct result of ineffective coordination and cooperation among stakeholders, from both the public and private sectors, together with complicated regulations and laws, which has limited the extent to which the local community tourism is able to benefit from development and investment opportunities which a strong tourism industry could potentially provide.
Conclusions from the case study affirm that Iraq al-Amir and its surrounding areas are suitable for tourism development, due to its diverse range of attractions, one of the major factors relating to successful tourism. Diversity of attractions is a key motivation for tourists to visit a destination. Without attractions, there is no need to supply facilities and services. Potential facilities and services provided for tourist related activities could also be used by the local population, thus significantly improving quality of life in the case study area, which currently lacks such infrastructure.
As a result of the almost continuous climatic warming since the end of the Little Ice Age, a large store of unconsolidated material is available for mobilization by different sediment transport processes in the proglacial areas of the Alps. This can also be stated for the area around the Gepatsch glacier in the Upper Kauner Valley (Ötztal Alps, Tyrol). Consequences are changes in the sediment budget of the catchment of the Gepatsch reservoir.
The main goal of this thesis was the construction of a recent time sale sediment budget of this area. An important methodological property of the conducted research was the usage of study area-wide LiDAR data (TLS and ALS) of comparatively high temporal and spatial density. After several billion measurement points and data from field work, mapping and modelling efforts had been processed and evaluated, it was possible to identify and quantify the sediment transport by all relevant processes on the scale of the study area.
As this study was conducted in the framework of the PROSA project, it was possible to enrich own results with data from other working groups. This formed the basis for a regionalization of measured rates to the scale of the 62 km² large study area.
Results are presented and discussed for the processes of rock fall of various magnitudes, debris flows, avalanches, creep on talus, fluvial processes (hillslopes and main fluvial system) and rates obtained for rock glaciers and glaciers. In order to make different processes comparable, the potential energy transformed was also calculated.
The resulting sediment budget (reference time period 2012-2014) does not only show the relative importance of the mentioned processes and spatial subunits (proglacial vs. non-proglacial) in the Upper Kauner Valley. It also gives insight into the importance of high-magnitude events and the configuration of the sediment transport system with regard to its connectivity.
Tourism studies have understood tourism as a “Western” phenomenon, which tended to neglect the presence of “non-Western” tourists and to over-generalise the application and universality of their theories. By now, tourism has become a global phenomenon with growing numbers of “emergent tourists”, especially from China. However, its quantitative importance, the touristic performances of this source market, and especially those of Chinese outbound organized mass tourists in western tourism stages continue to be under-researched. Moreover, the analysis of the Chinese outbound tourism phenomena encompasses mostly economic and business driven-studies and reports, which look for homogeneity instead of plurality of voices.
Drawing from all of the above, the aim of this interdisciplinary research is, therefore, to explore and provide further understanding of the tourism performances of Chinese outbound organized mass tourists on German tourism stages. To achieve this, the research draws on the performance approach in tourism research.
The research is based on a phenomenological approach. Part of the study’s field research was conducted largely from 2011 to 2012, both in China and Germany. In China, information was gathered by using open and semi-structured in-depth expert interviews with representatives from the Chinese tourism industry, tourism boards, as well as with tourism academics. In Germany, the ethnographic fieldwork consisted of participant observations, semi-structured interviews and short questionnaires to Chinese outbound tourist members of group package tours organized by Chinese-German travel companies. Furthermore, expert interviews were conducted with German industry representatives, experts and academics in 2013. As far as the analysis of the field research is concerned, the study relies on the GABEK qualitative method of research analysis supported by the WinRelan 32 software.
As part of the discussion, this research argues that the examination of tourism practices and behaviours of Chinese outbound organized mass tourists under the performance metaphor is able to provide further understanding on the previously neglected tourism consumption of “non-Western” tourists. Within the findings, it was possible to identify both modern und post-modern characteristics of the Chinese outbound organized mass market. This concurs with the recent de-differentiation between the typical tourism binaries (everyday-holiday and home-away) found in tourism theory by acknowledging that everyday conventions and habits inform touristic performances of Chinese tourists in Germany. Moreover, the research presents insights that allow to corroborate the future presence of organized mass tourists in the Chinese outbound market, as well as to de-inferiorise and de–homogenise the segment. With regard to German stages, the research highlights the opportunities and challenges Germany´s tourism industry still has ahead of it. Finally, the study presents a number of implications for future practice, which can be useful to plan a long-term strategy for Chinese outbound tourism.
The theories of design patterns and their practical implications exemplified for e-learning patterns
(2013)
Patterns are an efficient and successful way to capture best practices and access the tacit knowledge of experts. While the basic concept of patterns is simple and applicable in various domains there are many gaps in understanding the deeper meanings of the approach. This work will explore the nature of patterns and pattern languages by discussing the state-of-the-art, linking the pattern concept to its original ideas and develop a theoretical framework to understand the relations and differences between patterns in the world, patterns in our heads and pattern descriptions.
The common ground for patterns is to capture the context, problem, conflicting forces, a generative solution and the consequences in written form. To discuss the meanings of these analytical perspectives a path metaphor will be introduced in this thesis. The concepts will be linked to Alexander’s original ideas and common views from the pattern community. We will also identify gaps such as the weak understanding of the different problem levels that should be addressed in a pattern. Moreover, the thesis will reason about the quality of patterns by reflecting on wholeness and its properties.
The major contribution is the foundation of a framework that links the pattern concept to established theories from other disciplines. Patterns in the world are related to the philosophical idea of universals. A thought experiment will show the problems of abstracting and dividing a structure into parts and patterns. The construction of patterns in our heads is explained according to schema theory. Different experiences can lead to different pattern ideas. In our view the descriptions of patterns is similar to the formulation of theories. A pattern is a network of statements about the interaction of forces in a given context. Its proposed solution is supposed to resolve the existing conflict of forces. Such claims are subject to falsification and can be treated as hypotheses about good design. While good patterns are grounded on empirical cases, the generalized forms cannot be relieved from the problem of induction - what has worked in the past does not necessarily work in future cases. Patterns need to be tested continuously and evolve based on new data. From these considerations we will derive practical guidance for pattern mining.
The proposed theoretical framework will be supported by empirical findings. The lessons learnt from an authoring system that generates patterns of interactive graphics show that we can create many variations of instances based on the same universal code. This universal, however, is something artificially constructed by designers. It does not proof that this universal represents the world appropriately. To see whether individuals construct similar patterns we will report on the results from a laboratory study. The experiment tests the construction of schemas of interactive graphics. We will also reflect on pattern descriptions as the result of mining processes. Depending on the format, granularity and level of abstraction these descriptions contain different amounts of testable instructive information. A retrospective document analysis will compare different descriptions of patterns to illustrate this point.
The main contribution of this work is to show the variety of ideas about patterns, the underlying theories and relations between patterns in the world, patterns in our heads and pattern descriptions. These relations show that patterns are socially and mentally constructed. At the one hand patterns try to capture one view of the reality that can be tested empirically. On the other hand pattern descriptions also influence which artefacts are created in the future. There is a feedback loop as patterns capture a perceived reality and potentially shape parts of the future reality, i.e. new objects in the world.