Soil seed banks of remnant and degraded Swartland Shale Renosterveld

Questions: What are the characteristics of soil seed banks in highly endangered renosterveld vegetation and adjacent degraded sites? What is the contribution of the soil seed bank to restoring renosterveld vegetation after degradation through agriculture or afforestation? Location: Tygerberg Nature Reserve – one of the largest remaining fragments of Swartland Shale Renosterveld, Cape Floristic Region, South Africa. Methods: Assessment of vegetation, soil parameters and soil seed banks in three renosterveld sites, two adjacent abandoned fields, one pine plantation and one pine plantation clear-cut site. Smoke primer (i.e. fire surrogate) was applied to soil seed bank samples to evaluate fire as a possible management and restoration tool. Results: Abandoned agricultural fields adjacent to renosterveld remnants are characterized by alien grass cover, nutrient enrichment of the soil and depletion of the indigenous soil seed bank. In contrast, pine plantations show less alien species infestation, soil nutrient alteration and have a viable soil seed bank as well as re-development of indigenous renosterveld vegetation after clearance. Seedling recruitment was not significantly influenced by application of a smoke primer compared to the magnitude of fire response in fynbos. Conclusion: Abandoned agricultural fields (previously renosterveld) at Tygerberg have a very low restoration potential. In contrast, pine plantation sites should be given priority in restoration, because soil chemistry is less significantly altered and a viable indigenous soil seed bank is still present, which can be successfully activated through clearance management

The role of an efficient characterization of plant extracts for breeding and the transition from wild collection to controlled cultivation

Die Inkulturnahme noch nicht fest etablierter Heil- und Gewürzpflanzen steht vor folgendem Dilemma: Einerseits ist eine steigende Nachfrage nach Ware aus kontrolliertem, dokumentiertem, überprüfbarem, heimischem Anbau zu verzeichnen und eine Erhöhung der Anbauflächen dieser Arten politisch gewünscht. Andererseits wird die Anbauware im Preis, je nach Versorgungslage, mit dem Preis der Ware aus Wildsammlungen verglichen. Bei vergleichbaren Qualitäten erhält dann in der Regel die preiswertere Wildsammelware den Vorzug im Einkauf. Dies führt dazu, dass eine kontinuierliche Versorgung der Verarbeitungsbetriebe mit Ware aus kontrolliertem Anbau immer wieder zusammenbricht, da die Anbauer sich nicht auf Preise und Abnahme verlassen können. Auswege aus diesem Dilemma bestehen darin, entweder mit dem Anbau zu warten, bis die Wildsammlungen versagen oder das anzubauende Material qualitativ deutlich von der Wildsammelware abzugrenzen. An den Beispielen Echte Arnika (Arnica montana L.) und Russischer Löwenzahn (Taraxacum kok-saghyz L.E.Rodin) wird gezeigt, dass - vom Wildmaterial ausgehend - in den ersten Selektionszyklen enorm große Zuchtfortschritte erzielt werden können; vorausgesetzt die Ziele sind klar definiert und es steht eine ausreichende Analytik-Kapazität zur Verfügung. Eine solche kann beispielweise mittels moderner Kernspinresonanzspektroskopie (NMR) mit entsprechender software-basierter Datenanalyse realisiert werden und wird im Folgenden, im oben genannten Kontext, diskutiert.The cultivation of not yet well-established medicinal and herbal plants faces the following dilemma: On the one hand there is an increasing demand for goods from controlled, documented, verifiable, domestic cultivation and an increase in the acreage of these species is politically desired. On the other hand, the cultivated product is compared in price, depending on the supply situation, with the price of the product from wild collections. Usually, this results in the use of the cheaper wild collected goods. As a result, the continuous supply of raw material from controlled cultivation to the processing plants collapses time and again as growers can not rely on prices and acceptance. The solution to this dilemma is either to wait with the cultivation until the wild collections fail or the quality of the material to be grown is clearly differentiated from the wild collection. Based on two examples, Arnica (Arnica montana L.) and Russian Dandelion (Taraxacum kok-saghyz L.E.Rodin), is demonstated that - starting from the wild material - high breeding progress can be achieved in the first selection cycles. A necessary precondition is, that the goals are clearly defined and that there is sufficient capacity available to analyze output traits and lead ingredients. Such can be realized for example by means of modern nuclear magnetic resonance (NMR) analysis techniques with appropriate software-based data analysis and will be discussed below

The role of an efficient characterization of plant extracts for breeding and the transition from wild collection to controlled cultivation

Die Inkulturnahme noch nicht fest etablierter Heil- und Gewürzpflanzen steht vor folgendem Dilemma: Einerseits ist eine steigende Nachfrage nach Ware aus kontrolliertem, dokumentiertem, überprüfbarem, heimischem Anbau zu verzeichnen und eine Erhöhung der Anbauflächen dieser Arten politisch gewünscht. Andererseits wird die Anbauware im Preis, je nach Versorgungslage, mit dem Preis der Ware aus Wildsammlungen verglichen. Bei vergleichbaren Qualitäten erhält dann in der Regel die preiswertere Wildsammelware den Vorzug im Einkauf. Dies führt dazu, dass eine kontinuierliche Versorgung der Verarbeitungsbetriebe mit Ware aus kontrolliertem Anbau immer wieder zusammenbricht, da die Anbauer sich nicht auf Preise und Abnahme verlassen können. Auswege aus diesem Dilemma bestehen darin, entweder mit dem Anbau zu warten, bis die Wildsammlungen versagen oder das anzubauende Material qualitativ deutlich von der Wildsammelware abzugrenzen. An den Beispielen Echte Arnika (Arnica montana L.) und Russischer Löwenzahn (Taraxacum kok-saghyz L.E.Rodin) wird gezeigt, dass - vom Wildmaterial ausgehend - in den ersten Selektionszyklen enorm große Zuchtfortschritte erzielt werden können; vorausgesetzt die Ziele sind klar definiert und es steht eine ausreichende Analytik-Kapazität zur Verfügung. Eine solche kann beispielweise mittels moderner Kernspinresonanzspektroskopie (NMR) mit entsprechender software-basierter Datenanalyse realisiert werden und wird im Folgenden, im oben genannten Kontext, diskutiert.The cultivation of not yet well-established medicinal and herbal plants faces the following dilemma: On the one hand there is an increasing demand for goods from controlled, documented, verifiable, domestic cultivation and an increase in the acreage of these species is politically desired. On the other hand, the cultivated product is compared in price, depending on the supply situation, with the price of the product from wild collections. Usually, this results in the use of the cheaper wild collected goods. As a result, the continuous supply of raw material from controlled cultivation to the processing plants collapses time and again as growers can not rely on prices and acceptance. The solution to this dilemma is either to wait with the cultivation until the wild collections fail or the quality of the material to be grown is clearly differentiated from the wild collection. Based on two examples, Arnica (Arnica montana L.) and Russian Dandelion (Taraxacum kok-saghyz L.E.Rodin), is demonstated that - starting from the wild material - high breeding progress can be achieved in the first selection cycles. A necessary precondition is, that the goals are clearly defined and that there is sufficient capacity available to analyze output traits and lead ingredients. Such can be realized for example by means of modern nuclear magnetic resonance (NMR) analysis techniques with appropriate software-based data analysis and will be discussed below

The use of branch piles to assist in the restoration of degraded semiarid steppes

Desertification is a major environmental problem in arid and semiarid regions. Tree plantation has been commonly employed to foster the recovery of degraded areas. However, this technique is costly, and their outcomes are often uncertain. Therefore, we evaluated an alternative method for the restoration of degraded semiarid steppes that involved the construction of branch piles to attract frugivores as potential seed‐dispersing birds, promoting seed rain, and fostering the formation of woody patches. We measured the success of branch piles in terms of the number of bird visits and seed input compared to naturally occurring shrub patches. Generally, frugivorous birds visited branch piles less frequently than shrub patches. Yet, branch piles accumulated seeds of patch‐forming shrub species. Seed rain was higher under patches of the dominant shrub Rhamnus lycioides than under branch piles. In contrast, woody patches and branch piles did not differ in seed input of the less abundant Pistacia lentiscus shrub. Our study demonstrates that branch piles are used by frugivorous birds and accumulate seeds of patch‐forming shrubs. Branch piles may be a suitable method to promote the expansion of bird‐dispersed plant species and restore semiarid wooded steppes. However, their efficiency largely depends on pile persistence and economic cost.This project was financially supported by the Spanish Ministry of Education and Competitiveness (projects UNCROACH, CGL2011-30581-C02-01 and GRACCIE Programa Consolider-Ingenio 2010, CSD2007-00067). AC was supported by a Gerónimo Forteza contract (FPA/2014/080), Conselleria d’Educació, Cultura i Esport, Generalitat Valenciana)

An Equine Model for Vaccination against a Hepacivirus: Insights into Host Responses to E2 Recombinant Protein Vaccination and Subsequent Equine Hepacivirus Inoculation

Equine hepacivirus (EqHV) is the closest known genetic homologue of hepatitis C virus. An effective prophylactic vaccine is currently not available for either of these hepaciviruses. The equine as potential surrogate model for hepacivirus vaccine studies was investigated, while equine host responses following vaccination with EqHV E2 recombinant protein and subsequent EqHV inoculation were elucidated. Four ponies received prime and booster vaccinations (recombinant protein, adjuvant) four weeks apart (day −55 and −27). Two control ponies received adjuvant only. Ponies were inoculated with EqHV RNA-positive plasma on day 0. Blood samples and liver biopsies were collected over 26 weeks (day −70 to +112). Serum analyses included detection of EqHV RNA, isotypes of E2-specific immunoglobulin G (IgG), nonstructural protein 3-specific IgG, haematology, serum biochemistry, and metabolomics. Liver tissue analyses included EqHV RNA detection, RNA sequencing, histopathology, immunohistochemistry, and fluorescent in situ hybridization. Al-though vaccination did not result in complete protective immunity against experimental EqHV inoculation, the majority of vaccinated ponies cleared the serum EqHV RNA earlier than the control ponies. The majority of vaccinated ponies appeared to recover from the EqHV-associated liver insult earlier than the control ponies. The equine model shows promise as a surrogate model for future hepacivirus vaccine research

An Equine Model for Vaccination against a Hepacivirus: Insights into Host Responses to E2 Recombinant Protein Vaccination and Subsequent Equine Hepacivirus Inoculation

Equine hepacivirus (EqHV) is the closest known genetic homologue of hepatitis C virus. An effective prophylactic vaccine is currently not available for either of these hepaciviruses. The equine as potential surrogate model for hepacivirus vaccine studies was investigated, while equine host responses following vaccination with EqHV E2 recombinant protein and subsequent EqHV inoculation were elucidated. Four ponies received prime and booster vaccinations (recombinant protein, adjuvant) four weeks apart (day −55 and −27). Two control ponies received adjuvant only. Ponies were inoculated with EqHV RNA-positive plasma on day 0. Blood samples and liver biopsies were collected over 26 weeks (day −70 to +112). Serum analyses included detection of EqHV RNA, isotypes of E2-specific immunoglobulin G (IgG), nonstructural protein 3-specific IgG, haematology, serum biochemistry, and metabolomics. Liver tissue analyses included EqHV RNA detection, RNA sequencing, histopathology, immunohistochemistry, and fluorescent in situ hybridization. Al-though vaccination did not result in complete protective immunity against experimental EqHV inoculation, the majority of vaccinated ponies cleared the serum EqHV RNA earlier than the control ponies. The majority of vaccinated ponies appeared to recover from the EqHV-associated liver insult earlier than the control ponies. The equine model shows promise as a surrogate model for future hepacivirus vaccine research

Renosterveld remnants – Current ecological situation and restoration perspectives

West Coast Centre renosterveld in the Western Cape of South Africa is highly fragmented and threatened due to conversion by agriculture, urbanization and the effects of invasive alien species. Currently, insufficient data on ecological processes and restoration priorities of this endangered vegetation type exist. Therefore, this thesis is an attempt to close knowledge gaps, starting with a review of renosterveld research in chapter one. Integrating available research results, the study explored renosterveld at different levels. In chapter two, the ecosystem status of pristine and adjacent degraded renosterveld (abandoned agricultural field, pine plantation) was assessed via vegetation, soil and seed bank surveys, allowing the evaluation of restoration potential. In chapter three, the effect of smoke primer as a fire-surrogate was tested on soil seed banks of pristine and degraded renosterveld. In chapter four, experiments with alien species Echium plantagineum from different habitats were conducted in order to examine fire-dependency on germination behavior. In chapter five, experiments were set up to test restoration methods that are novel to abandoned fields in renosterveld. These restoration experiments mimicked natural re-colonization processes by sowing pioneer species (Otholobium hirtum) and installing bird perches to enhance seed rain of frugivorous birds. Furthermore, a pine clearing experiment and recovery from the indigenous soil seed bank were observed. The last three chapters assessed population genetic consequences of habitat fragmentation in two annual Scrophulariaceae (Hemimeris racemosa and Nemesia barbata). Study results for pristine renosterveld seed bank showed a high level of alien species, whereas abandoned fields had a depleted indigenous soil seed bank and insufficient restoration potential. In contrast, the indigenous soil seed bank of pine plantation was still viable and high restoration potential could be assumed. This was mirrored by the only successful restoration experiment (pine clearing). Despite promising tests, seeds from the other two restoration experiments were not capable to establish in-vivo. Although fire-surrogate is regarded a useful management tool to sustain high species number, caution is needed when alien infestation exists. Genetic analysis revealed usual genetic variation within and between populations and fragmentation regions for both species. Therefore, minor impact of fragmentation on the study species can be assumed. Concluding, nature conservation resources should be invested in habitat protection and restoration of pine plantations and not in abandoned fields that are very difficult to manipulate. Although habitat fragmentation influence on genetic variation was low in this study, it cannot be assumed that this is also valid for other species. Further genetic investigations in this fragmentation context should follow and are promising

Genetic variation of two species with different life-history traits in the endangered renosterveld of South Africa – a comparative analysis of Eriocephalus africanus and Hemimeris racemosa

We tested the effects of life-history traits on genetic variation and conducted a comparative analysis of two plant species with differing life-history traits co-occurring in the highly endangered renosterveld of South Africa. We selected eighteen renosterveld remnants with varying degrees of size and isolation where populations of the herbaceous, annual and insect-pollinated Hemimeris racemosa and the shrubby perennial and both wind- and insect-pollinated Eriocephalus africanus occurred. We postulated a lower genetic variation within populations and increased genetic variation between populations in the annual than in the perennial species. Genetic variation was lower within populations of H. racemosa than within E. africanus, as is typical for annual compared to perennial species. Variation within populations was, however, not correlated with fragment size or distance in either of the two species and genetic variation between populations of the two species was comparable (ΦST = 0.10, 0.09)