|
(36-07) Heavy metal risk assessment at the ecosystem level using Terrestrial Model Ecosystems . Kools, Stefan*,1, Boivin, Marie-Elene1,2, van der Wurff, Andre3, van Gestel, Cornelis1, Verhoef, Herman1, van Straalen, Nico1, 1 Vrije Universiteit Amsterdam, Institute of Ecological Science, Amsterdam, The Netherlands2 National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands3 Wageningen University, Laboratory of Nematology, Wageningen, The Netherlands ABSTRACT- Elevated metal levels in soil are suspected to induce shifts in communities and affect ecosystem functioning. However, risk assessment of heavy metal pollution often focuses on research at species level. In this investigation we use the terrestrial model ecosystem concept to assess effects of soil pollution on community and system functioning. Eighty intact soil cores were taken from a polluted area. This area has been subjected to heavy metal pollution due to household waste and manure during the last 300 years, but is now considered as a nature reserve. The cores were evaluated on their ecological functioning and structure of bacteria and nematode communities. Forty high and 40 low polluted (Pb, Cu, Zn) cores were incubated at standard laboratory conditions. Soil functioning is assessed as nitrification, humification, degradation, soil respiration and susceptibility to rainwater containing zinc as additional stress. Total concentration of zinc (Zn) after the treatment increased the background pollution with 100, 400 and 1600 mg/kg Zn. Results of system parameters are presented. It is expected that these dosages will highly affect structural aspects, but effects on functioning will show resilience during incubation. Responses of higher polluted cores will be more pronounced than cores with lower background pollution levels. Key words: heavy metals, ecological functioning, soil community, terrestrial model ecosystems |
