Research for the Environment


Ecological effect mechanisms of toxicants

Toxicants affect biota not only directly but also through ecological changes in their environment. We identify relevant processes and develop models for the assessment of toxicant effects in aquatic ecosystems.

Biological Organization Levels

Abiotic stress, competition and predation influence the impact of toxicants at all levels of biological organization.

  • As additional stressors, they make organisms more vulnerable than expected from standard test systems [1].

  • Within a population, they can prolongate the recovery time after a contamination event [2].

  • The reduction of a species being sensitive to toxicants will affect the overall community structure [3]. Thus, also insensitive species can be affected via the foodweb [4].

We characterize relevant eclogical mechanisms in aquatic ecosystems, focusing on macroinvertebrate communities. The results from individual tests, higher tier experiments (incl. our self-developed test system "Nanocosm") and field studies are combined to provide mechanism based models and references for a realistic risk assessment.

 Key Papers

  1. Knillmann S, Stampfli NC, Beketov MA, Liess M, 2012. Intraspecific competition increases toxicant effects in outdoor microcosms. Ecotoxicology, 21, 1857–1866.
  2. Liess M, Foit K, 2010. Intraspecific competition delays recovery of population structure. Aquatic Toxicology, 97, 15-22.
  3. Beketov MA, Schäfer RB, Marwitz A, Paschke A, Liess M, 2008. Long-term stream invertebrate community alterations induced by insecticide thiacloprid: effect concentrations and recovery dynamic. Science of the Total Environment, 405(1-3), 96-108.
  4. Foit K, Chatzinotas A, Liess M, 2010. Short-term disturbance of a grazer has long-term effects on bacterial communities - Relevance of trophic interactions for recovery from pesticide effects. Aquatic Toxicology 99, 205-211.


Online applications

Recent publication

Becker JM, Liess M 2015. Biotic interactions govern gentic adaptation to toxicants. Proceedings of the Royal Society B. 282 (1806): published online.


Diversity prevents resistance.


Dept. of System Ecotoxicology
Building 6.0
Permoserstrasse 15
04318 Leipzig

Prof. Dr. Matthias Liess
Tel: +49 341 235-1578

Tel: +49 341 235-1263
Fax: +49 341 235-1785