Insektengemeinschaften im Wandel

Mit weltweit über einer Million beschriebener Arten stellen Insekten die höchste Artenvielfalt aller Organismen-Gruppen dar. Insekten erbringen wichtige Ökosystemleistungen wie Bestäubung oder natürliche Schädlingsbekämpfung und haben eine wichtige Rolle in den Nährstoffkreisläufen. Dazu sind sie eine wichtige Nahrungsquelle nicht nur für diverse Gliedertiere, sondern auch für Wirbeltiere wie Vögel, Säugetiere, Reptilien und Amphibien. Die Zerstörung der Lebensräume, die Intensivierung der Landwirtschaft oder der Klimawandel wirken sich stark auf die Insektenfauna aus. Das Forschungsprojekt "Insekten-Gemeinschaften im Wandel" untersucht, wie und ob sich die Artengemeinschaften von wichtigen Zeigerorganismen, Laufkäfer, Kurzflügelkäfer und Spinnen, auf landwirtschaftlichen Flächen der Nordwest-Schweiz, in den letzten 25 Jahren verändert haben. Mit Bodenfallen wird das Vorkommen dieser drei Nützlingsgruppen in Getreidefeldern und in natürlichen Hecken auf unterschiedlich intensiv bewirtschafteten landwirtschaftlichen Betrieben untersucht. Der Vergleich soll aufzeigen, welche anbautechnischen Massnahmen die Insektengemeinschaften beeinflussen. So können konkrete Massnahmen zum Schutz und Erhalt der Insekten hergeleitet werden. https://www.fibl.org/de/themen/projektdatenbank/projektitem/project/199

Long-term slope stability of abandoned mine lake - numerical modelling and risk assessment

International audienceAlmost all post exploitation open pit mines in the world are shaped as a final reservoir intended to be filled with water. In Europe, the creation of water lakes is the most common way of reclaiming post open pit mines. The safety and the security of mine lakes is one of the priorities of mine regions. One of the main hazards identified is the slope stability of lake banks. To develop a reliability methodology for assessing the long-term stability of flooded open pit mines, a large-scale numerical model of the lake was carried out and was applied on Lake Most, which is one of the largest mining lakes in Europe (Czech Republic). The large-scale numerical model was built, based on the site observations, large scale LiDAR data and geotechnical data. The results highlighted the reliability of the methodology to combine the geometric model with the geological model to create a large-scale numerical model, and to identify local and potentially instable zones

Nanostructural defects evidenced in failing silicon-based NMOS capacitors by advanced failure analysis techniques

International audienc

Funktionelle Biodiversität im Obstbau – Chancen und Risiken. Massgeschneiderte Blühelemente zur agrar-ökologischen Verbesserung

Inhalt: - Wirkungsvolle Nützlingsstreifen in Intensiv-Obstanlagen - Reiche Bandbreite an Massnahmen zur ökologischen Aufwertung - Blühstreifen in Fahrgassen, Baumstreifen oder als Reservoir (Randbereiche) in Obstanlagen - Nützlingsstreifen als ein Teil der Pflanzenschutz-Strategie - Wirkung der Blühstreifen sehr Kontext spezifisch - Anlage der Blüh-/Nützlingsstreifen in Obstanlagen - Pflege der Nützlingsstreifen – spezielle Blühstreifenmulcher - Mulchintensität beeinflusst die Pflanzenvielfalt der Nützlingsstreifen - Nützlingsstreifen-Mischung in Kirschen (Vers. 2019 mod.) - Hohe Anforderungen an Saat-Mischung –Weiterentwicklung nötig! - Deutlich höhere Pflanzenvielfalt in Anlagen mit Blühstreifen - Herausforderung der Etablierung von Nützlingsstreifen in Kirschen - Erhöhte Vielfalt und Blühdichte dank Streifen in Kirschenanlagen - Nützlingsgruppen mit unterschiedlichen Nahrungsspektren - Europa weiter Test der Blühstreifen – EU Projekt ‘EcoOrchard’ - Erhöhte Nützlingsdichten in Anlagen mit Blühstreifen - Nützlingsstreifen fördern Nützlinge auf den Apfelbäumen - Blattlausräuber im direkten Bezug zur mehligen Apfelblattlaus - Reduzierte Entwicklung der mehligen Apfelblattlaus über die Saison und geringere Fruchtschäden - Effekte unterschiedlicher Fahrgassenvegetation auf Nützlinge (Belgische Studie) - Spinnenförderung bereits im ersten Jahr/Herbst in den Kirschen - Blattlauskolonien und natürliche Gegenspieler in den drei Bereichen – mit, nahe, ohne Streifen - Anteile der erfassten Nützlingsgruppen – 3 Jahre mit visueller Kontrolle in den Bäumen - Interaktionen Jahr und Nützl./Schwebfliegen mit Blattläusen - Mögliche Faktoren für die geringe Wirkung der Streifen im gedeckten Kirschenanbau - Eingesetzte Biopestizide in den Kirschen – Bandbreite - Intensität - Positive Resultate in konv. Kirschenanlage in UK – 3-jähriges Monitoring - Wildbienen in Blühstreifen, Kontrollfläche und Saum – D-Studie - Wildbienen in Kontrollfläche, Blühstreifen, zwei Heckentypen - in D - Effekte verschiedener Anbauintensitäten auf die Fauna-Vielfalt - Fazi

Colonizing islands of water on dry land - on the passive dispersal of fish eggs by birds

The vast majority of global freshwater ecosystems are small lakes with less than 100 m 2 surface area. These lakes are often unconnected to other water bodies but frequently host fish populations. Existing explanations for how fish colonize such remote habitats often involve birds as vectors transporting fish eggs as propagules. In this study, we aim to quantify the prevalence of these explanations among relevant societal groups as well as their scientific knowledge basis. We analyzed entries in online blogs and forums and surveyed the opinions of local stakeholders and decision makers using a questionnaire. To collect published scientific knowledge, we conducted a structured literature review. Our results reveal a discrepancy between commonly found beliefs and the empirical knowledge supporting those beliefs: Dispersal of fish eggs by water birds was overall the most frequent explanation online and in the questionnaire. In the scientific literature, however, we found hardly any empirical research on passive fish egg dispersal. We propose research directions for how to close this gap of knowledge and suggest that future empirical studies on passive fish egg dispersal may be inspired by existing work on passive dispersal in aquatic invertebrates. Mitigating the belief‐evidence discrepancy on fish dispersal will be essential to better understand the patterns of fish biodiversity across landscapes, to counteract its losses, and inform management strategies for invasive fish species

An underground research laboratory at Château-Landon (France) to study the impact of climate change on the stability of abandoned mines

International audienceIn January 1910, a chalk mine at Château-Landon in the Paris basin brutally collapsed, causing 7 fatalities. This dramatic event was related to the centennial flood of the Seine River and one of its tributaries, the Loing River, which invaded the lower parts of the mine and eventually weakened the entire structure. To understand the conditions that triggered the disaster and anticipate other catastrophic event of this kind elsewhere, the Royer mine, located in the same area, was chosen to host an underground scientific observatory. Its goal is to study water–rock interactions and in particular water circulation and unusual ground saturation conditions on the behaviour of chalk. The Royer chalk mine is shallow, above the water-table, easily accessible and globally stable. It has been equipped with a high resolution multiparameter monitoring network in 2019; all the sensors are connected to The French National Monitoring Centre for Ground and Underground risks (Cenaris). Besides from in situ observations and monitoring, series of laboratory tests are carried out on samples to study the impact of hydraulic cycles on the short- and long-term behaviours of chalk. A hydromechanical model is also under development to analyse the results and better assess the overall stability of the mine in the context of climate of change. In this paper, we provide a brief summary on the challenges to assess geohazards from abandoned chalk mines, and then present in detail the observatory, its objectives and perspectives, as well as the first results after two years of activity

Flower reservoirs in stone fruit orchards: creating self- regulating systems with a low input strategy

Promotion of biodiversity has great potential to contribute to organic fruit growing by increasing and facilitating natural pest control. Flower strips are a known management strategy used in orchards and vegetable production and used to provide habitat for beneficial insects increasing biocontrol of pests and pollination of crop plants. However, in organic stone fruit production perennial flowers strips are not as widely implemented because of the logistical challenges (for example additional machinery) and high efforts needed for maintenance of flowers strips. Pest population build up in orchards is facilitated by enclosures and therefore there is a need to promote biocontrol agent’s diversity and abundance in orchards as well as pollination. In this project, we will exploit our large experience in Agroecology, to promote biodiversity and natural pest control in organic orchards with a low input strategy. The overall goal of this research project is to test whether flower reservoirs implemented in areas adjacent to the tree rows and in anchoring areas where tractors do not transit can provide similar benefits as those provided by flower strips in the orchard alley, while reducing the logistical challenges and maintenance efforts needed from farmers, and therefore, increasing its acceptance and implementation

Predation on native fish eggs by invasive round goby revealed by species‐specific gut content DNA analyses

Conservation of riverine fish often aims to improve access to spawning grounds and restore longitudinal connectivity by removing migration barriers, and involves substantial investments. However, these investments also enable non‐native predators to invade upstream into spawning areas and potentially adversely affect the recruitment of threatened freshwater fish through egg or fry predation. Detecting egg predation is often challenging. Visual inspections of fish gut contents may underestimate predation of soft materials such as eggs and fry, which limits the discovery of predators preying upon these life‐stages. DNA‐based detection assays may offer a more sensitive tool to assess predation of soft materials. A conservation issue was confirmed by developing and applying a species‐specific DNA‐based detection assay: invasive round goby (Neogobius melanostomus) prey on the eggs or fry of the threatened common nase (Chondrostoma nasus) in Switzerland. DNA‐based detection assays were also developed for five other valuable native fish species, including endangered salmonid and cyprinid river spawners. The applicability of the assays was confirmed in a series of laboratory and field feeding experiments involving eggs and fish tissue. In addition, this work provides a guiding framework for conservation managers regarding the use and applicability of different DNA‐based detection approaches for gut content analysis. The results of this study could inform local conservation measures – such as temporary reductions in the density of round goby at spawning sites prior to spawning – and demonstrate how targeted application of species‐specific molecular markers may advance freshwater fish management