RWTH Aachen University , Germany
Andreas Schaeffer finished his PhD in chemistry in 1984 ...
... He worked as postdoc at Harvard University and the University of Zuerich until 1989, joined industry in Basel until 1997 and since then works as professor for Environmental Biology and Chemodynamics at RWTH Aachen University until now (www.bio5.rwth-aachen.de). His research interests relate to the metabolism of organic xenobiotics in soil, water and sediments and plants, remediation strategies and the effects of pollutants on terrestrial and aquatic organisms. From 2000-2007 he was scientific director of the Fraunhofer Institute of Environmental Chemistry and Ecotoxicology, Schmallenberg. Since 2003 he is also director of the Research Institute for Environmental Analysis and Assessment in Aachen (www.gaiac. rwth-aachen.de), a spin-off company of the university group. In 2012 and 2014 he became adjunct and honorary professor at Nanjing and Chongqing universities, respectively. He is member of various committees working on the environmental risk assessment of chemicals.
Considering multiple stress in the environmental risk assessment of chemicals in soil
Andreas Schaeffer1, Wulf Amelung2, Matthias Kaestner3, Ellen Kandeler4, Richard Ottermanns1, Holger Pagel4, Stephan Peth5, Gerhard Rambold6, Michael Schloter7, Thilo Streck4, Martina Roß-Nickoll1
1 RWTH Aachen University, Institute for Environmental Research (Biology 5), 52074 Aachen, Germany
2 Soil Science and Soil Ecology, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Nussallee 13, 53115 Bonn, Germany
3 Helmholtz-Centre for Environmental Research – UFZ, Department of Environmental Biotechnology, 04318 Leipzig, Germany
4 Soil Science and Land Evaluation, University of Hohenheim, Emil Wolff Str. 27, 70599 Stuttgart, Germany
5 Department of Soil Science, University of Kassel, Nordbahnhofstr. 1a, 37213 Witzenhausen; Germany
6 Systematic Botany and Mycology, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
7 Helmholtz Zentrum München, Research Unit for Environmental Genomics, Ingolstädter Landstr. 1, 85758 Oberschleissheim, Germany
Soils are faced with man-made chemicals, such as the input of organic or metal-containing pesticides, and non-chemical stressors like soil compaction due to agricultural traffic and natural disturbance like water logging or drought. Although multiple stress factors are typical in the environment, research on this aspect and especially in soil sciences is limited. Based on a short review of resilience theory [1-2], a concept for research will be presented on the ability of soil contaminated by chemicals as one stressor to resist further natural or anthropogenic stress and to retain its functions and structure. There is strong indication that pollution as a primary stressor will change the system reaction of soil, i.e., its resilience, stability and resistance. It can be expected that pollution affects the physiological adaption of organisms and the functional redundancy of the soil to further stress. We hypothesize that the recovery of organisms and chemical-physical properties of soil after impact of a chemical or natural stressor in polluted soil differs from that in non-polluted soil, i.e., polluted soil has a lower resilience compared to that of not or less contaminated soil. Thus, a polluted soil might more easily change into another system regime after occurrence of further stress, with no return to the original system state. We highlight this issue by presenting two examples: one on the combination of chemical stress and non-chemical stress (Cu contamination and soil compaction), the other on multiple chemical stress (application of several pesticides within typical agricultural spray series). We propose to intensify research on effects of combined stresses involving a multidisciplinary team of experts and provide suggestions for corresponding experiments. A mechanistic understanding of the reaction of soils to multiple stressors would pave the way to enhance ecological theory and to render the environmental risk assessment of chemicals more realistic.
 Holling CS, Johnston RF (1973): Resilience and stability of ecological systems. Annu. Rev. Ecol. Syst. 4, 1-23.
 Schaeffer A, Amelung W, Hollert H, Kaestner M, Kandeler E, Kruse J, Miltner A, Ottermanns R, Pagel H, Peth S, Poll C, Rambold G, Schloter M, Schulz S, Streck T, Roß-Nickoll M (2016): The impact of chemical pollution on the resilience of soils under multiple stresses: a conceptual framework for future research. Sci. Total Environ. 568,1076-1085.