Current developments in soil ecotoxicology and the need for strengthening soil ecotoxicology in Europe: results of a stakeholder workshop

BACKGROUND: Soil is one of our most important resources and fulfills many ecological functions such as storage and filtration of water and nutrients, transformation of chemical compounds and nutrients, biomass production, and carbon storage. Such soil functions support ecosystem services provided by soils, which need to be protected to protect soil fertility. However, European soils often contain elevated concentrations of contaminants, putting biodiversity of soil organisms as well as the ecological functions and services at risk. To promote soil ecotoxicology in Switzerland, the Swiss Centre for Applied Ecotoxicology together with the Federal Office for Environment and the Federal Office for Agriculture organized a stakeholder workshop on 7 June 2018 with participants from research, governmental bodies, and associations. One goal of this workshop was to inform participants about currently available risk assessment approaches for soil, the soil risk assessment for plant protection products in Europe, available bioassays and bioindicators, and results of research projects on soil contaminants in Switzerland. Another goal was to discuss the needs for research in soil ecotoxicology in Switzerland and to identify next steps, potential projects, and future collaborations. RESULTS: The main needs identified during the workshop were the establishment of (bio)indicators to measure soil fertility, functional parameters to determine soil functions, and the preservation of soil biodiversity. Another priority listed was the formation of a working group, which addresses the issue of the development of environmental quality standards for soil. The need for experimental field sites for implementing and testing new approaches or tools for assessing soil quality was also discussed. CONCLUSION: The next steps planned are two workshops with national and international experts in soil ecotoxicology to develop a soil monitoring concept for Switzerland and to find suitable bioindicators to evaluate soil fertility. Additionally, a literature review will be performed summarizing the current ecotoxicological state of the art with regard to the development of bioindicators in relation to the monitoring of plant protection products in Swiss soil, to evaluate their effects on soil fertility. Furthermore, all attendees agreed on the need for annual meetings or workshops where experts can present scientific results, participants can exchange information, and future projects and collaborations can be developed.