River Experiment Leipzig

Toxicant disturb ecological processes. We identify relevant mechanisms and develop models for the risk assessment in aquatic ecosystems.

From test tubes to communities
In ecosystems, pollutants often affect communities at much lower concentrations than in laboratory systems [4, 6]. We investigate the underlying processes from the individual organism [2] to the population [1] and community level [3, 7, 8, 9] using test systems and mathematical models [5]. Relevant factors for the prediction of low effect concentrations in the field are primarily based on the combined effect of multiple stressors [5, 7, 8].

Stream experiment Leipzig
Since 2005 we have been running a unique stream mesocosm facility for realistic toxicant assessment. Currently, the facility is based on 47 large-scale artificial streams, which harbor also rare and sensitive species. Here we quantify effects of plant protection products on nearly natural ecosystems and test our mechanistic models for risk assessment.


  • Research and further development of innovative risk assessment technologies as part of the official assessment strategy and their further development through projects and co-operation with e.g. industrial partners, universities and other research institutions.
  • Technology transfer (training of technical authorities and engineering offices, workshops, pilot studies)

Selected publications

  1. Schunk F, Liess M. 2023. Ultra-low esfenvalerate concentrations increase biomass and may reduce competitiveness of Daphnia magna Populations. Science of the Total Environment. Science of the Total Environment 886 (2023) 163916. DOI: 10.1016/j.scitotenv.2023.163916
  2. Schunck F. Liess M. 2022. Time between sequential exposures to multiple stress turns antagonism into synergism. Environmental Science & Technology. 
  3. Reiber L, Foit K, Liess M, Karaoglan B, Wogram J, Duquesne S. 2022. Close to reality? Micro-/mesocosm communities do not represent natural macroinvertebrate communities. Environmental Sciences Europe.
  4. Liess M, Liebmann L, Vormeier P, Weisner O, Altenburger R, Borchardt D, Brack, Werner, Chatzinotas A, Escher B, Foit K, Gunold R, Henz S, Hitzfeld K L, Schmitt-Jansen M, Kamjunke N, Kaske O, Knillmann S, Krauss M, Küster E, Link M, Lück M, Möder M, Müller A, Paschke A, Schäfer RB, Schneeweiss A, Schreiner VC, Schulze T, Schüürmann G, von Tümpling W, Weitere M, Wogram J, Reemtsma T. 2021. Pesticides are the dominant stressors for vulnerable insects in lowland streams. Water Research 117262
  5. Liess M, Foit K, Knillmann S, Schäfer RB, Liess H-D. 2016. Predicting the synergy of multiple stress effects. Scientific Reports 6: 32965.
  6. Beketov MA, Kefford BJ, Schäfer RB, Liess M 2013. Pesticides reduce regional biodiversity of stream invertebrates. Proceedings of the National Academy of Sciences of the United States of America, 110 (27), 11039 - 11043.
  7. Liess M, Foit K, Becker A, Hassold E, Dolciotti I, Kattwinkel M, Duquesne S 2013. Culmination of low-dose pesticide effects. Environmental Science & Technology, 47 (15), 8862 - 8868.
  8. Knillmann S, Stampfli NC, Noskov YA, Beketov MA, Liess M 2013. Elevated temperature prolongs long-term effects of a pesticide on Daphnia spp. due to altered competition in zooplankton communities. Global Change Biology 19 (5), 1598 - 1609.
  9. Liess M, Beketov M 2011. Traits and stress - keys to identify community effects of low levels of toxicants in test systems. Ecotoxicology 20 (6), 1328 - 1340.