Lecture, Research profile seminar
The current epoch is characterised by an unprecedented influence of human societies on ecosystems through multiple anthropogenic stressors. These stressors range from habitat degradation over invasive species to pollution including by toxicants. Professor Ralf B. Schäfer will first present recent studies on the co-occurrence of stressors and chemicals in the field and present two research avenues to deal with these phenomena: 1) Prioritisation of mixtures and stressors and 2) Advancement of predictive capabilities using theoretical models.
The current epoch is characterised by an unprecedented influence of human societies on ecosystems through multiple anthropogenic stressors. These stressors range from habitat degradation over invasive species to pollution including by toxicants. The co-occurrence of these stressors is rather the norm. Moreover, given that approximately 30,000-70,000 chemicals are in daily use and many such as pesticides are deliberately emitted, environmental chemical exposure alone is often characterised by the co-occurrence of multiple chemicals.
Many studies for all kinds of ecosystems have examined potential interactions between stressors and between toxic chemicals, though largely for two-stressor or two chemical interactions. Recent meta-analyses of two-stressor interactions across ecosystems (and their constituting organisms) displayed a high variability in the prevalence of additive, less than additive (antagonistic) and more than additive (synergistic) interactions with respect to the standard additive model for stressor interaction.
Similarly, studies showed that the effects of 70% of 2-10 compound mixtures showed a deviation of up to 300%, with up to a 12-fold exceedance of the predicted effects (Cedergreen et al., 2008; Nørgaard and Cedergreen, 2010) when using current models for mixture effects. However, empirically testing the effects of all possibly co-occurring stressors and chemical mixtures is rendered impossible by the huge number of possible combinations. Thus, theoretical advances of our predictive capacities are urgently needed.
Lecturer: Lecturer: Professor Dr. Ralf B. Schäfer (Phd 2008), working group leader in Quantitative Landscape Ecology, is professor at the University Koblenz-Landau since 2010 in the Institute for Environmental Sciences. With other 130 staff members and 12 professors, the Institute for Environmental Sciences is one of the largest german University Institutes devoted to research in the Environmental Sciences. Ralfs main expertise is the exposure and effects of different environmental stressors, with a particular emphasis on organic toxicants, on freshwater invertebrates, microbes and ecosystem functions using field investigations and different statistical and spatial modelling techniques. He has published over 80 articles in international peer-reviewed journals including leading multidisciplinary journals.
Date: 1/31/2018
Time: 9:00 AM - 12:00 PM
Categories: Sustainable development, Research, Environment
Organizer: The FRAM Centre
Location: Universitetsbyggnaden Vasaparken, Universitetsplatsen 1, Gula salongen
Event URL: Read more about Multiple stressors and chemical mixtures: A joint challenge?
Contact person: Daniel Slunge
