Modified forests are vital for species communities and ecological functionality in a heterogeneous South African landscape

Land-use change is a major threat to forest ecosystems worldwide. Therefore, understanding the effects of human forest modification on biodiversity is an important task for conservation ecologists. The main objective of my dissertation was to evaluate how different intensities of forest modification contribute to the maintenance of species diversity and ecosystem functionality in a human-modified landscape. For this purpose, I based my studies in a heterogeneous landscape around two nature reserves, Vernon Crookes and Oribi Gorge, in KwaZulu-Natal, South Africa. I selected six most representative types of scarp forest modification – ranging from continuous forest and natural forest fragments in nature reserves to fragments within plantations and agricultural matrix, forested gardens, and secondary forest. In a total of 36 study sites, I assessed flower-visiting insects using insect traps and recorded local bird assemblages with point counts. Further, I observed flower visitation and seed removal on the native and widespread tree Celtis africana (Ulmacea) to analyse whether forest modification affects pollination and seed dispersal services. To assess how forest configuration affects the dispersal of animals, I carried out an in-depth study on the movement behaviour of bird assemblages within and among forest patches in the Vernon Crookes region. By means of direct observations and bird mist-netting, I followed up bird movements across nine forest fragments belonging to three different forest types. In all these three projects I give special attention to the responses of the different functional groups of a species community. The richness of flower-visiting insects, community composition and flower visitation on C. africana differed significantly among the different forest types and between two study seasons in 2009 and 2010. Both flower visitor richness and flower visitation rates were strongly enhanced in the human-modified forests. This could be explained by a high abundance of large-bodied pollinators in these sites. In particular, feral honey bees (Apis mellifera) played a major role in the pollination of C. africana trees located in forest fragments within plantations and agriculture, forested gardens and secondary forests. However, effective fruit set of C. africana was not enhanced by an increase of flower visitation, possibly due to the tree’s capability of wind pollination. This implies that even though forest modification can strongly alter insect assemblages, pollination services for trees with unspecialized flowers may remain resilient at a landscape scale. Bird species richness was not significantly different among forest types. However, I found a significant increase in bird abundance in modified forests. In particular, fragments within agriculture, forested gardens, and secondary forests attracted a large number of forest generalists, shrubland and open country species. The abundance of forest specialists however, was much lower in modified forests. Changes in the composition of bird functional groups were also confirmed by multivariate analysis, which clearly separated bird communities by forest type. I found the highest abundance of frugivores visiting C. africana in natural forest fragments, fragments within agriculture, forested gardens and secondary forests. That was also true for the estimated total fruit removal per C. africana tree, even though the differences among the forest types were not significant. In summary, I could show that overall bird abundance and seed removal services can be enhanced in modified forests. However, the results also underline the importance of protected natural forest for bird specialist species sensitive to human disturbance. I found a very high movement activity of the overall bird community among the nine forest fragments that was significantly structured by bird functional groups. Especially, frugivorous birds, forest specialists and large-bodied species showed the highest dispersal abilities across the landscape. These results might be facilitated by overall high fragment quality, providing food and shelter, as well as the close proximity among the forest fragments within the landscape. Yet, a fourth-corner analysis revealed that even though modified forests were rather attractive to frugivores, forest specialists as well as large-bodied species, there was still a high affinity of the latter functional groups to natural forest fragments, close canopy cover and large fragment size. Only a small proportion of the overall bird community was recorded to steadily persist in the forest fragments. In particular, patches in the agricultural landscape were frequently used by resident insectivores and forest generalists. Ultimately, these findings suggest that remnant forest fragments may represent valuable stepping-stones as well as permanent habitat for many forest birds and thus, will help to maintain regional bird assemblages in human-modified landscapes. Overall, my results strongly suggest that modified forests contribute to the maintenance of species diversity and ecosystem functionality in a human-modified landscape. With respect to a vast increase of human-modified forests worldwide, evidence of a high conservation potential of these habitats is encouraging news for conservation managers. In particular, modified forests that are located in close proximity to protected areas have high conservation priority as they may expand buffer zones around natural forests in human-modified landscapes. Generalizations, however, should be considered with caution. My findings strongly emphasize that human-modified forests do not completely compensate for the overall loss of natural habitat. High sensitivity of forest specialist species and overall changes in local community composition demonstrate that natural forests are essential to maintain species diversity at a larger scale. Additionally, high flexibility towards habitat changes of many species in the study region might be based on the patchy historic distribution of scarp forest that has strongly been determined by terrain and orographic conditions of the environment. Thus, it is possible that an evolutionary adaptation has lessened the vulnerability of the region’s fauna and flora to the present anthropogenic forest fragmentation. Ultimately, most of the forest types in the study region are characterized by high habitat quality, including for example resource availability, structural heterogeneity and close proximity to further forest patches, so that altogether, they contribute to the high species diversity. Consequently, the maintenance of structurally rich forest habitat is essential to maintain species diversity and ecological functionality in human-modified landscapes

Nicht-invasive Evaluation der Lebermanifestation der Zystischen Fibrose (CFLD) bei Erwachsenen mit Acoustic Radiation Force Impulse (ARFI) - Imaging, Transienter Elastographie (TE) und verschiedenen Fibrosescores

In der vorliegenden medizinischen Promotionsschrift werden verschiedene nicht-invasive Untersuchungsverfahren bei erwachsenen Patienten mit Zystischer Fibrose (CF) zur Detektion einer Leberbeteiligung (CFLD) evaluiert. Das diagnostische Standard-verfahren bei vielen Hepatopathien, die Leberbiopsie, ist auf Grund der fokalen Manifestation der CFLD und der häufigen pulmonalen Begleiterkrankung bei CF nicht Bestandteil der Routinediagnostik. CF- Patienten werden daher im Rahmen der vorliegenden Studie mittels konventionellen Ultraschalls, Acoustic Radiation Force Impulse (ARFI) - Imagings, Transienter Elastographie (TE) und verschiedener Fibrosescores untersucht. Ferner wird die Eignung der elastographischen Methoden als Verlaufsparameter bei einem Teil der Studienkohorte evaluiert. Ziel ist die Bewertung des diagnostischen Nutzens der angewandten Untersuchungsmethoden bezüglich der Differenzierung zwischen CF-Patienten ohne Leberbeteiligung, CFLD und CFLD-induzierter Zirrhose. Lebergesunde Probanden und Patienten mit ethyltoxischer Leberzirrhose dienen als Kontrollgruppen. Die Ergebnisse dieser wissenschaftlichen Arbeit zeigen, dass die elastographische Untersuchung der Leber bei erwachsenen CF- Patienten, als nicht-invasives Verfahren im Rahmen der Routinediagnostik zur Detektion einer CFLD-induzierten Zirrhose, ergänzend genutzt werden kann. Für die Beurteilung des klinischen Nutzens als Verlaufsparameter sind weitere Studien notwendig.:A Abkürzungsverzeichnis B Promotionsschrift 1 Bibliographische Beschreibung 2 Einführung 2.1 Zystische Fibrose 2.2 Cystic Fibrosis related Liver Disease – CFLD 2.3 CFLD-Diagnostik 2.3.1 Leberhistologie 2.3.2 Konventioneller Ultraschall 2.3.3 Neue diagnostische Ansätze 2.3.3.1 Elastographieverfahren 2.3.3.1.1 Transiente Elastographie (TE) 2.3.3.1.2 Acoustic Radiation Force Impulse (ARFI) – Imaging 2.3.3.2 Serummarker und Fibrosescores 2.3.3.2.1 AST-to-platelet-ratio-index (APRI) -Score 2.3.3.2.2 Forns-Score 2.4 Rationale der vorliegenden Studie 3 Eigener Beitrag zu der Publikation 4 Publikationen 4.1 Publikation 1 4.1.1 Skizzierung der 1. Publikation 4.1.2 Originalpublikation 1 4.2 Publikation 2 4.2.1 Skizzierung der 2. Publikation 4.2.2 Originalpublikation 2 5 Zusammenfassung der Arbeit 5.1 Grundlagen und Durchführung 5.2 Ergebnisse und Auswertung C Literaturverzeichnis D Erklärung über die eigenständige Abfassung der Arbeit E Curriculum vitae F Publikationen G Danksagun

Petri net supported control of complex controlling processes in a management holding: an application-oriented consideration from the perspective of coordination

In Anbetracht der steigenden Komplexität und Dynamik von Unternehmensprozessen ist das Interesse an entscheidungsunterstützenden, prozessorientierten Beschreibungsmethoden sowohl in der betriebswirtschaftlichen Praxis als auch Forschung ungebrochen. Konzernierte Unternehmen in Gestalt der zeitgemäßen Management-Holding sehen sich aufgrund ihrer Größe, Heterogenität und Multinationalität in besonderem Maße mit intransparenten Steuerungsprozessen konfrontiert. Zur Handhabung dieser relativen Führungskomplexität wird die Konzeption des koordinationsorientierten Konzerncontrolling herangezogen. Mit Hilfe vertikaler, horizontaler und zeitlicher Koordinationsprozesse sollen die fraktalen Führungsteilsysteme auf die Wertsteigerung des Gesamtkonzerns ausgerichtet werden. In instrumenteller Hinsicht zeigt sich jedoch, dass das controllingtypische Instrumentarium nur bedingt in der Lage ist, komplex-dynamische Sachverhalte prozessorientiert nachzubilden. Insofern resultiert aus den spezifischen Anforderungen ans Konzerncontrolling eine instrumentelle Lücke, zu deren Schließung die prozessorientierten Beschreibungsmethoden System Dynamics, Ereignisgesteuerte Prozessketten sowie Petri-Netze diskutiert werden. Aus der synoptischen Betrachtung geht ein qualitatives Vorteilhaftigkeitsprofil hervor, welches die Petri-Netz-Methode als problemadäquat erscheinen lässt. Erstmalig wird die ingenieurwissenschaftliche Petri-Netz-Methode aus dem Blickwinkel des präventiven Meta-Controlling zur Modellierung informatorischer Controlling-Prozesse innerhalb einer Management-Holding angewandt und so das Instrumentarium des Konzerncontrolling erweitert. Im Zuge dieser Komplementierung wird das äußerst facettenreiche Leistungspotenzial von Petri-Netzen aufgezeigt. Die Praxistauglichkeit im Hinblick auf Schwachstellenanalyse und Gestaltungsempfehlungen wird anhand der fiktiven Fallstudie „Petrimobil AG“ unter Einsatz des EDV-gestützten CPN-Tools verifiziert.The interest in decision-supporting, process-oriented description methods is so well in the business management practice and research unbroken in consideration of the increasing complexity and dynamics of enterprise processes. Group enterprises in the form of the up-to-date management holding feel confronted with non-transparent control processes due to their size, differences and multi-nationality in special measure. For the handling of this relative leadership complexity the conception of the coordination oriented group controlling is consulted. With the help of vertical, horizontal and temporal coordination processes the fractal leadership partial systems shall on the increase in value of the entire group enterprise. In regard with instruments it turns out, however, that the controlling typical instruments only caused are able to model complex dynamic facts process-orientedly. In this respect a gap with regard to instruments results from the specific requirements on the group controlling to whose shutdown the process-oriented description methods system dynamics, event-driven process chains as well as Petri nets are discussed. A qualitative profitability profile which makes the Petri net method seem problem adequate results from the synoptic consideration. The engineer scientific Petri net method is for the first time used for the modeling of informational controlling processes of inner half one management holding from the viewpoint of the preventative meta controlling and enlarges so the instruments of the group controlling. In the course of this complementation the extremely multifaceted performance potential of Petri nets is shown. The practice suitability with regard to weak-points analysis and design recommendations is verified using the fictitious case study "Petrimobil AG" below use of the EDP supported CPN tool

In-ovo Straußeneimodell als präklinisches Bildgebungsverfahren: physiologischer Gasaustausch und Pharmakokinetik von Narkosegasen

Tierversuche waren und sind heute noch ein grundlegender Bestandteil der Wissenschaft. Doch der Wunsch nach alternativen Forschungsmethoden nimmt immer mehr zu. Das In ovo-Modell ist ein Ansatz, die Zahl der Tierversuche zu verringern und den Versuchstieren unnötige Leiden zu ersparen. Bislang bedeutete In ovo-Forschung im weitesten Sinne die Untersuchung forschungsrelevanter Fragen anhand von Hühnereiern und – embryonen. Um das In ovo-Modell besser in ein klinisches Umfeld zu integrieren und Theorie und Praxis am Ort zu vereinen, soll zukünftig das Straußenei in der Wissenschaft etabliert werden. Vor einem nuklearmedizinischen Hintergrund ergibt sich die Möglichkeit, neu entwickelte Radiopharmaka anhand der Straußenembryonen zu testen und die Untersuchung als PET/CT-Aufnahme zu dokumentieren. Jegliches bildgebende Verfahren erfordert jedoch die Immobilität des Embryos, um Bewegungsartefakte zu vermeiden. Zu diesem Zweck wurden die Straußeneier in einem eigens für dieses Vorhaben entwickelten Messsystem von den volatilen Anästhetika Isofluran und Desfluran umgeben. Während der Messung wurden die prozentualen Volumenanteile für Isofluran und Desfluran sowie für Sauerstoff (O2) und Kohlenstoffdioxid (CO2) in der Messkammer aufgezeichnet. Mithilfe dieses Messverfahrens konnte sowohl ein physiologischer Gasaustausch von O2 und CO2 über die Eischale eruiert werden als auch die Aufnahme der Narkosegase in das Ei quantifiziert werden. Die Aufnahmerate in das Ei zeigte sich abhängig vom jeweiligen Narkosegas und der Konzentration, in welcher es dargeboten wurde. Von Beginn bis Ende einer Messung nahm die Aufnahmerate kontinuierlich ab. Die zwei untersuchten Flurane als Narkosegase werden demnach diffusiv in das Ei aufgenommen und können hypothetisch beim Straußenembryo zu einer Immobilisierung führen. Bezüglich letzterem müssen weitere Untersuchungen erfolgen

Synthese von Sulfaten und Sulfatderivaten ausgewählter Metalle unter drastischen Bedingungen

Es wurden aus Oleum neue Sulfate von Vanadium(IV/V) synthetisiert und charakterisiert. Des Weiteren gelang es das erste Tantal(V)-sulfat aus Ta2O5 und SO3 bei 150 °C zu synthetisieren und strukturell aufzuklären. Durch Einsatz von Methansulfonsäure als Lösungsmittel und Reaktant konnten auf unterschiedlichen Synthesewegen die wasserfreien Methansulfonate Mn(CH3SO3)2 und Fe(CH3SO3)2, Ga(CH3SO3)3, In(CH3SO3)3 und Tl(CH3SO3)3, sowie VO(CH3SO3)2 und SnCl2(CH3SO3)2 erhalten werden. Für Thallium war es möglich, zwei gemischtanionische Verbindungen der Zusammensetzung TlX2(CH3SO3) (X = Cl oder Br) zu erhalten. In der Verbindung M[Mo2(CF3SO3)5]∙2CF3SO3H (M = Rb oder Cs) wurde eine Mo2-Hantel, in der Molybdän in der Oxidationsstufe +II vorliegt, realisiert, deren spezielle Bindungssituation quantenmechanisch analysiert wurde. Für Zinn und Blei konnten Verbindungen der Formel Sn(CF3SO3)2 und Pb(CF3SO3)2 erhalten werden, sowie die Addukte Pb(CF3SO3)2(CF3SO3H) und Pb(CF3SO3)2(CF3SO3

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Metatranscriptomics reveals contrasting effects of elevation on the activity of bacteria and bacterial viruses in soil

Soil microbial diversity affects ecosystem functioning and global biogeochemical cycles. Soil bacterial communities catalyse a diversity of biogeochemical reactions and have thus sparked considerable scientific interest. One driver of bacterial community dynamics in natural ecosystems has so far been largely neglected: the predator-prey interactions between bacterial viruses (bacteriophages) and bacteria. To generate ground level knowledge on environmental drivers of these particular predator-prey dynamics, we propose an activity-based ecological framework to simultaneous capture community dynamics of bacteria and bacteriophages in soils. An ecological framework and specifically the analyses of community dynamics across latitudinal and elevational gradients have been widely used in ecology to understand community-wide responses of innumerable taxa to environmental change, in particular to climate. Here, we tested the hypothesis that the activity of bacteria and bacteriophages codeclines across an elevational gradient. We used metatranscriptomics to investigate bacterial and bacteriophage activity patterns at five sites across 400 elevational metres in the Swiss Alps in 2015 and 2017. We found that metabolic activity (transcription levels) of bacteria declined significantly with increasing elevation, but activity of bacteriophages did not. We showed that bacteriophages are consistently active in soil along the entire gradient, making bacteriophage activity patterns divergent from that of their putative bacterial prey. Future efforts will be necessary to link the environment-activity relationship to predator-prey dynamics, and to understand the magnitude of viral contributions to carbon, nitrogen and phosphorus cycling when infection causes bacterial cell death, a process that may represent an overlooked component of soil biogeochemical cycles

The heterogeneity of wooded-agricultural landscape mosaics influences woodland bird community assemblages

Context Landscape heterogeneity (the composition and configuration of different landcover types) plays a key role in shaping woodland bird assemblages in wooded-agricultural mosaics. Understanding how species respond to landscape factors could contribute to preventing further decline of woodland bird populations. Objective To investigate how woodland birds with different species traits respond to landscape heterogeneity, and to identify whether specific landcover types are important for maintaining diverse populations in wooded-agricultural environments. Methods Birds were sampled from woodlands in 58 2 x 2 km tetrads across southern Britain. Landscape heterogeneity was quantified for each tetrad. Bird assemblage response was determined using redundancy analysis combined with variation partitioning and response trait analyses. Results For woodland bird assemblages, the independent explanatory importance of landscape composition and landscape configuration variables were closely interrelated. When considered simultaneously during variation partitioning, the community response was better represented by compositional variables. Different species responded to different landscape features and this could be explained by traits relating to woodland association, foraging strata and nest location. Ubiquitous, generalist species, many of which were hole-nesters or ground foragers, correlated positively with urban landcover while specialists of broadleaved woodland avoided landscapes containing urban areas. Species typical of coniferous woodland correlated with large conifer plantations. Conclusions At the 2 x 2 km scale, there was evidence that the availability of resources provided by proximate landcover types was highly important for shaping woodland bird assemblages. Further research to disentangle the effects of composition and configuration at different spatial scales is advocated

Scatter-hoarding birds disperse seeds to sites unfavorable for plant regeneration

Scatter-hoarding birds provide effective long-distance seed dispersal for plants. Transporting seeds far promotes population spread, colonization of new areas, and connectivity between populations. However, whether seeds transported over long distances are deposited in habitats favorable to plant regeneration has rarely been investigated, mainly due to methodological constraints. To investigate dispersal patterns and distances of Swiss stone pine (Pinus cembra) seeds we utilized advances in tracking technology to track the movements of their sole disperser, the spotted nutcracker (Nucifraga caryocatactes). We found routine individual movements between single seed harvesting and seed caching site. Harvesting sites of individual birds overlapped, whereas seed caching sites were separated and located on average 5.3 km away from the harvesting site. Interestingly, most distant caching sites were located at low elevations and in spruce forest, where Swiss stone pine does not naturally occur. This suggests that nutcrackers disperse seeds over long distances but that a large portion of these seeds are cached outside the known pine habitat. Therefore, we conclude that the implications of such long-distance seed dispersal movements for plant populations should be carefully considered in combination with the effects of habitat quality on plant recruitment

Downsizing of animal communities triggers stronger functional than structural decay in seed-dispersal networks

Downsizing of animal communities due to defaunation is prevalent in many ecosystems. Yet, we know little about its consequences for ecosystem functions such as seed dispersal. Here, we use eight seed-dispersal networks sampled across the Andes and simulate how downsizing of avian frugivores impacts structural network robustness and seed dispersal. We use a trait-based modeling framework to quantify the consequences of downsizing—relative to random extinctions—for the number of interactions and secondary plant extinctions (as measures of structural robustness) and for long-distance seed dispersal (as a measure of ecosystem function). We find that downsizing leads to stronger functional than structural losses. For instance, 10% size-structured loss of bird species results in almost 40% decline of long-distance seed dispersal, but in less than 10% of structural loss. Our simulations reveal that measures of the structural robustness of ecological networks underestimate the consequences of animal extinction and downsizing for ecosystem functioning.Fil: Donoso, Isabel. Senckenberg Biodiversity and Climate Research Centre; AlemaniaFil: Sorensen, Marjorie C.. Senckenberg Biodiversity and Climate Research Centre; Alemania. University of Guelph; Canadá. Goethe Universitat Frankfurt; AlemaniaFil: Blendinger, Pedro Gerardo. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Kissling, W. Daniel. University of Amsterdam; Países BajosFil: Neuschulz, Eike Lena. Senckenberg Biodiversity and Climate Research Centre; AlemaniaFil: Mueller, Thomas. Senckenberg Biodiversity and Climate Research Centre; AlemaniaFil: Schleuning, Matthias. Senckenberg Biodiversity and Climate Research Centre; Alemani