Gewinnung von Basissaatgut für die produktionsintegrierte Förderung seltener und gefährdeter Ackerwildkräuter

Re-introduction and integrated conservation of rare arable plants is one approach to restore agro-biodiversity. Our study investigated occurrence and population size of rare arable plant species on 94 fields in Bavaria. 50 threatened species could be found with populations >100 individuals. This enabled an initial collection of seeds which will be propagated and sown in extensively managed fields

Wiederansiedlung seltener und gefährdeter Ackerwildpflanzen auf Ökobetrieben. Teilprojekt Freising: Einfluss von Feldfrucht und Aussaatzeitpunkt

Intensive land use has led to a drastic decline of arable weeds in Central Europe. The objective of the project “Restoration of local populations of rare and endangered arable field plants on organic farms in Germany” is to develop methods for a successful re-establishment of arable weeds on fields where absence of herbicides provides favourable development conditions. Two complementary approaches are tested by research teams at Freising and Witzenhausen. In Freising two exact trials were set up in order to find suitable crops and dates for the initial sowing of three rare and endangered species (Consolida regalis, Legousia speculum-veneris, Lithospermum arvense). The study area is located in the Munich Plain which is characterized by limestone gravel. First results show a better establishment of all three species on plots with a reduced sowing density of the crop. Furthermore, sowing in early autumn seems to be beneficial for the establishment of the study species

MoPeDT: A Modular Head-Mounted Display Toolkit to Conduct Peripheral Vision Research

Peripheral vision plays a significant role in human perception and orientation. However, its relevance for human-computer interaction, especially head-mounted displays, has not been fully explored yet. In the past, a few specialized appliances were developed to display visual cues in the periphery, each designed for a single specific use case only. A multi-purpose headset to exclusively augment peripheral vision did not exist yet. We introduce MoPeDT: Modular Peripheral Display Toolkit, a freely available, flexible, reconfigurable, and extendable headset to conduct peripheral vision research. MoPeDT can be built with a 3D printer and off-the-shelf components. It features multiple spatially configurable near-eye display modules and full 3D tracking inside and outside the lab. With our system, researchers and designers may easily develop and prototype novel peripheral vision interaction and visualization techniques. We demonstrate the versatility of our headset with several possible applications for spatial awareness, balance, interaction, feedback, and notifications. We conducted a small study to evaluate the usability of the system. We found that participants were largely not irritated by the peripheral cues, but the headset's comfort could be further improved. We also evaluated our system based on established heuristics for human-computer interaction toolkits to show how MoPeDT adapts to changing requirements, lowers the entry barrier for peripheral vision research, and facilitates expressive power in the combination of modular building blocks.Comment: Accepted IEEE VR 2023 conference pape

New approaches to the conservation of rare arable plants in Germany

Der rasante technische Fortschritt der Landwirtschaft während der letzten Jahrzehnte hat einen dramatischen Rückgang seltener Ackerwildpflanzen verursacht. Um diesem Rückgang Einhalt zu gebieten, wurden verschiedene Artenschutzkonzepte wie das Ackerrandstreifenprogramm oder das aktuelle Programm ‘100 Äcker für die Vielfalt’ entwickelt. Für Sand- und Kalkäcker sind geeignete Bewirtschaftungsmethoden zur Erhaltung seltener Arten inzwischen gut erforscht. Für saisonal vernässte Ackerflächen, die ebenfalls viele seltene Arten aufweisen können, ist dagegen wenig über naturschutzfachlich geeignet Standortfaktoren und Bewirtschaftungsmethoden bekannt. Untersuchungen an sieben zeitweise überstauten Ackersenken bei Parstein (Brandenburg) zeigten, dass das Überstauungsregime und insbesondere die Dauer der Überstauung die Artenzusammensetzung der Bestände stark beeinflussen. Die aktuelle Bewirtschaftung zeigte dagegen weniger deutliche Auswirkungen auf Populationen der Zielarten Myosurus minimus und Elatine alsinastrum. Ein weiteres aktuelles Problem des Ackerwildpflanzenschutzes ist, dass seltene Arten oft auf Flächen vorkommen, wo ihr Überleben durch die derzeitige Bewirtschaftung akut gefährdet ist. Da die Richtlinien der ökologischen Anbauverbände intensive Bewirtschaftungsverfahren weitgehend einschränken, bietet der Ökologische Landbau günstige Voraussetzungen für den Schutz gefährdeter Ackerwildpflanzen. Wie deren Populationen erfolgreich in ökologisch bewirtschafteten Feldern etabliert werden können, wird in einem Feldversuch bei Gräfelfing in der Münchner Schotterebene untersucht. Erste Ergebnisse zu den winterannuellen Arten Legousia speculum-veneris und Consolida regalis zeigen, dass sich diese Arten erfolgreich in ökologisch bewirtschafteten Äckern etablieren lassen. Frühe Herbstsaat und eine reduzierte Kulturpflanzenkonkurrenz im Ansaatjahr erbrachten dabei die besten Erfolge. Bei reduzierter Kulturpflanzendichte führte Dinkel zu deutlich höheren Etablierungsraten als Roggen. Die Ergebnisse dieser Studie können einen wesentlichen Beitrag zur Erhaltung gefährdeter Arten in der Agrarlandschaft leisten, wenn der Transfer gefährdeter Ackerwildpflanzen in ökologisch bewirtschaftete Ackerflächen umgesetzt wird.Stichwörter: Artentransfer, Bewirtschaftung, Ökologischer Landbau, ÜberstauNeue Ansätze zum Artenschutz gefährdeter Ackerwildpflanzen in DeutschlandAbstractOver the past decades, the rapid improvement of agricultural technology has caused a dramatic decrease of rare arable plants. This process has stimulated the development of various concepts to protect these species such as the field margin program or more recently the program ‘100 fields for biodiversity’. For fields with sandy or calcareous soils, management practices to conserve the specific arable flora are well explored. For occasionally wet sites, however, which may also harbour various threatened species, little is known about suitable site conditions and conservation management. Studying seven seasonally flooded field sites close to Parstein (Brandenburg) showed that the flooding regime and particularly the duration of flooding strongly affect the composition of the apparent plant communities. Effects of different arable farming practices on the populations of the two target species Myosurus minimus and Elatine alsinastrum were less pronounced. Another urgent problem of arable plant conservation is that rare species frequently grow at sites where they are threatened by current cultivation. As management is less intense under organic farming, this system could provide suitable conditions for the conservation of threatened species. However, locally extinct species need to be actively reintroduced to overcome dispersal limitations. How these plants can be successfully established in fields under organic farming was studied in a field trial at Gräfelfing (Bavaria). Preliminary results on the winter annuals Legousia speculum-veneris and Consolida regalis indicate that rare arable plants can be successfully introduced to organic fields. Early autumn sowing and a low crop competition provide the most favourable conditions for their establishment. At reduced sowing rates, winter spelt allowed a much better establishment than winter rye. If the idea of transferring rare arable plants to organic farmland establishes in practice, results of this study could substantially contribute to the conservation of rare species in arable landscapes.Keywords: Arable weed, flooding, management, organic farming, species transfer, threatened species, wet fiel

Evidence for electronically-driven ferroelectricity in the family of strongly correlated dimerized BEDT-TTF molecular conductors

By applying measurements of the dielectric constants and relative length changes to the dimerized molecular conductor $\kappa$-(BEDT-TTF)$_2$Hg(SCN)$_2$Cl, we provide evidence for order-disorder type electronic ferroelectricity which is driven by charge order within the (BEDT-TTF)$_2$ dimers and stabilized by a coupling to the anions. According to our density functional theory calculations, this material is characterized by a moderate strength of dimerization. This system thus bridges the gap between strongly dimerized materials, often approximated as dimer-Mott systems at 1/2 filling, and non- or weakly dimerized systems at 1/4 filling exhibiting charge order. Our results indicate that intra-dimer charge degrees of freedom are of particular importance in correlated $\kappa$-(BEDT-TTF)$_2$X salts and can create novel states, such as electronically-driven multiferroicity or charge-order-induced quasi-1D spin liquids.Comment: 6 pages, 4 figures + Supplementary Information (8 pages, 8 figures

Reconciling the control of the native invasive Jacobaea aquatica and ecosystem multifunctionality in wet grasslands

Grasslands are managed to provide multiple goods and services. During recent decades, abandonment of marginal grasslands and intensification of the most productive sites resulted in biodiversity losses and reduced ecosystem services (ESs). Moreover, invasion by unwanted plants impaired ESs, as seen in Jacobaea aquatica, a poisonous native invader in pre-alpine grasslands of Central Europe. Invasion by this plant compromises fodder quality and endangers animal health, resulting in abandonment of grassland use. We tested different management regimes to reduce J. aquatica in wet grasslands of Southern Germany and assessed how its regulation affects grassland multifunctionality. We monitored indicators associated with productivity and conservation, such as the abundance of J. aquatica, forage quality, yield, abundance of specialists, and pollinator-relevant plants. Intensive management favoured multifunctionality by promoting productivity and biodiversity, yet also increasing the abundance of J. aquatica. Reduced management regulates J. aquatica cover close to an acceptable threshold while also reducing ESs. Thus, we conclude that moderate management strikes a balance between the control of the poisonous plant and the supply of grassland multifunctionality.publishedVersio

Einfluss von Deckfrucht und Fruchtfolge auf die Wiederansiedlung gefährdeter Ackerwildpflanzen

Due to recent intensification of land use the arable flora is considered to belong to the most threatened groups of plants in Europe. Therefore, the objective of the project ‘re-introduction of rare arable plants on organic farms in Germany’ is to develop methods for a successful re-establishment of arable plants on fields with favourable management conditions. The present study describes the effects of different cover crops and crop rotations on the establishment of three endangered species (Consolida regalis, Legousia speculum-veneris, Lithospermum arvense) in a field experiment at Gräfelfing close to Munich. Results from the first 3 years indicate that successful establishment mainly depends on crop competition during the 1st year. As individual species respond differently to crop competition, successful conservation may necessitate a spatially differentiated concept where management of different sites is adapted to the individual requirements of different species