Terrestrial model ecosystems (TME)
Terrestrial model ecosystems (TME) and other semi-field methods have been proposed as potential higher-tier test systems for a refined risk assessment (OEPP/EPPO, 2003, Van der Linden et al., 2006, Schäffer et al., 2010, Scholz-Starke et al. 2011). Recently higher-tier studies with soil organisms focussing on the community structure have become more important in ecological risk assessment of pesticides.
In the context of pesticide registration these community test systems become more and more important, because in these systems effects on the structure of complex soil communities can be determined and direct and indirect changes in the biocoenosis can be assessed.
We offer a to a large extent standardised method to investigate and quantify duration and extent of potential effects of pesticides on the structure of natural soil communities unter GLP.
The studies are performed with intact soil cores sampled from untreated grasslands (off-crop) including non-degenerated natural soil communities (worst-case scenario). After coring, the TME are immediately transported to the test facility in Aachen and placed into the tubes of the outdoor TME facility where the intact soil cores were maintained under natural sunlight and weather conditions. The construction of the TME facility assures a good drainage and a homogeneous water supply for all TME. In case of long-lasting extreme conditions, such as drought, we have the possibility to control the moisture conditions by sprinkle irrigation.
The objective of this outdoor TME study design is to monitor duration and magnitude of adverse impacts on the natural non-degenerated soil-mesofauna of collembolans, oribatid mites, enchytraeids and nematodes over a period of at least one year after application. Several studies have shown a stability of the biological community over one year.
The taxonomic determination of the different groups of organisms is mainly in-house and also with professional experts with whom there is close cooperation for years. The organisms can also be analysed in different soil depth. The analysis of the test substance is done in the analytical laboratory of our cooperation partners.
In addition, we offer the possibility to collect and quantify the leachate in specially designed TMEs.
Scholz-Starke B., Nikolakis A, Leicher T., Lechelt-Kunze C., Heimbach F., Theißen B., Toschki A., Ratte H. T., Schäffer A., Roß-Nickoll M. (2011): Outdoor Terrestrial Model Ecosystems are suitable to detect pesticide effects on soil fauna: design and method development. Ecotoxicology 20:1932–1948.
Toschki A, Hammers-Wirtz M, Hoelscher C, Theißen B, Roß-Nickoll (2011): Requirements for Terrestrial Model Ecosystems (TME) in Environmental Risk Assessment – influence of coring sites and management on microarthropod communities. Poster presentation, 21th SETAC- Europe Annal Meeting 15-19 May 2011, Milan, Italy.
Theiβen B, Scholz-Starke B, Hammers-Wirtz M, Kölzer U, Leicher T, Schäffer A, Roß-Nickoll M (2010): Does 'sequentially sampling' influence population dynamics of soil mesofauna in TME? An experiment giving answers to questions posed on the PERAS workshop. SETAC Europe 20th Annual Meeting, 23-27 May 2010, Seville, Spain.
Scholz-Starke B., Theißen B., Toschki A., Ratte H.T., Schäffer A., Heimbach F., Nikolakis A., & Roß-Nickoll M.: (2007): Basic Prerequisites Of A Semi-Field Terrestrial Model Ecosystem (TME):Ecology, Variability, Technical Set-Up & Resulting Test Strategies. Poster SETAC Europe 17th Annual meeting 20-24 May 2007, Porto, Portugal.
Roß-Nickoll M., Keppler J., Lechelt-Kunze C., Heimbach F., Nikolakis A., Ratte H.-T., Schäffer A., Theissen B., Toschki A. & B. Scholz-Starke (Presenter). (2006): Outdoor Terrestrial Model Ecosystems: Study Design & Evaluation Approaches. Poster SETAC Europe 16th Annual Meeting 7-11 May 2006, The Hague, The Netherlands.
Scholz-Starke B, Heimbach F, Keppler J, Lechelt-Kunze C, Lennartz G, Ratte HT, Theißen B, Toschki A, Schäffer A, Roß-Nickoll M (2005): Terrestrial Modell Ecosystems (to assess changes od micro-arthropods community structure). Poster SETAC Europe 15th Annual meeting, Lille, 2005.