333.7 Natürliche Ressourcen, Energie und Umwelt
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Smartphones make intensive use of precious metals and so called conflict minerals in order to reach their high performance in a compact size. In recent times, sustainability challenges related to production, use and disposal of smartphones are increasingly a topic of public debate. Thus, established industry actors and newly emerging firms are driven to engage in more sustainable practices, such as sustainable sourcing of materials, maintenance services or take-back schemes for discarded mobile phones. Many of these latter efforts can be related to the concept of a circular economy (CE). This thesis explores how CE-related value creation architectures (VCAs) in the smartphone industry contribute to slowing and closing resource loops in a CE. In order to analyze these new industry arrangements, transaction cost theory (TCT) is used as a guiding theory for a make-or-buy analysis. Combining TCT with the concept of a CE is a novel research approach that enables the empirical analysis of relationships between focal actors (e.g. manufacturers) and newly emerging loop operators (e.g. recycling firms) in the smartphone industry. Case studies of such VCAs are conducted with case companies drawn from the Innovation Network on Sustainable Smartphones (INaS) at Leuphana Universtity of Lüneburg and analyzed regarding their involved actors, partnerships, circular activities, motivation and perceived barriers. Evidence from the conducted case studies suggests that asset specificity for circular practices increases for higher order CE-loops such as maintenance or reuse, therefore long-term partnerships between focal actors and loop operators or vertical integration of CE practices are beneficial strategies to reach a sophisticated CE. Similarly, circular practices that go beyond recycling require a strong motivation, either through integration in the focal firm´s quality commitment or through business model recognition. It is further suggested that the circular design of products and services could reduce necessary transaction costs and thus overall costs of a circular economy. Four different integration strategies for circular economy practices have been derived from the conducted case studies. These are: 1) vertically integrated loops, 2) cooperative loop-networks, 3) outsourcing to loop operators and 4) independent loop operators. This work thus provides evidence that circular economy activities do not necessarily have to be managed by focal actors in the value chain. Rather, circular practices can also be put forward by specialized loop operators or even independent actors such as repair shops.
The effects of habitat fragmentation and land use changes are usually studied by relating patterns of genetic diversity and differentiation to environmental factors, habitat history, landscape structure, or to a combination thereof. However, these three drivers are rarely addressed simultaneously. In addition, these studies are usually carried out in conservation-driven contexts, and therefore tend to concentrate on hyper-fragmented landscapes and on rare or endangered species. However, how habitat fragmentation and land use affect widespread species in more typical landscapes has not been fully investigated. This thesis addresses these two gaps. Abax parallelepipedus, a flightless ground beetle with low dispersal power, was used as a model species to test how environmental factors, habitat history, and landscape structure affect genetic diversity and genetic differentiation in three study regions located across Germany. Although all of the study regions represent fairly typical rural landscapes for central Europe, each consisting of a complex matrix of land uses, they differ from one another in terms of environmental factors, habitat history, and landscape structure, and thus can serve as three test cases. In the first stage of the work, the investigator identified polymorphic microsatellite loci which could potentially be used to study genetic diversity and differentiation in A. parallelepipedus. She then developed PCR and genotyping protocols for two suites of loci, in the end selecting to use the set of 14 fully multiplexed loci for the study. After having developed the needed study system, she genotyped over 3300 beetles from 142 study sites. In her investigation of how environmental factors and habitat history affect genetic diversity and genetic differentiation, and found that genetic diversity was being driven by variables that could be related to population sizes rather than by habitat history. She also did not find evidence of an influence of habitat history on the genetic differentiation patterns. Although populations of A. parallelepipedus in the past were probably smaller due to deforestation, they apparently remained large enough to prevent rapid genetic drift. In addition, the researcher carried out a landscape genetics analysis of the genetic differentiation patterns found in each of her study regions, in which she examined the relationship between genetic differentiation and landscape structure. She tested whether she could find patterns of isolation by distance, isolation by resistance, or isolation by barriers in the study regions. No effects of land use or of fragmentation were found. Based on the importance of population sizes found in the previous study, combined with the beetle's known avoidance of non-wooded areas and its inability to cross roads, the investigator concludes that although there is probably little gene flow across the study regions, large population sizes are preventing the rapid development of genetic differentiation. Models simulating the development of genetic differentiation over time in populations of different starting sizes support this conclusion.
Wetterstationen
(2017)
Die Arbeiten dieser Anthologie wurden im Rahmen von Wetterstationen, einem Projekt mit fünf internationalen Partnern, das vom Kulturprogramm der Europäischen Union gefördert wird, in Auftrag gegeben. Schriftsteller und Schüler an den fünf Standorten nahmen an dem Projekt teil und der vorliegende Band enthält eine Auswahl ihrer Arbeiten.