# Selecting Bioassay Test Species at the Screening Level of Soil Ecological Risk Assessments
## 4 Conclusions  
In this study, we attempted to identify test species to represent ecological risk at the screening level of a site-specific SERA using nine bioassays of soil species. We found that soil algae, nematodes, and plants have the highest statistical correlation with the EtoxRI of soil. These results also indicate that previous studies conducted using earthworm or marine bacteria bioassays did not reflect site-specific ecological risk. Furthermore, \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Phylum or** & **Test Species (Endpoint)** & **Criteria of Selecting Test Species** & **Reference** \\ \hline Earthworm & _Eisenia andrei_ (Avoidance) & commonly recommended in soil & [24] \\ \hline Earthworm & _Lumbricus rubellus_ (Survival) & & \\ \hline Potworm & _Enchytraens albidus_ (Survival and reproduction) & used as indicator groups of soil species & [30] \\ \hline Plant & _Lactuca sativa_ (Seeds emergence and growth) & & \\ \hline Collembola & _Folsomia candida_ (Avoidance) & rapid and low cost, commonly recommended in soil & [25] \\ \hline Earthworm & _Eisenia andrei_ (Avoidance) & ecotoxicity assessment & \\ \hline Plant & Radish and red clova (Germination) & - & [26] \\ \hline Earthworm & _Eisenia fetida_ (Growth and reproduction) & & \\ \hline Potworm & _Enchytraens albidus_ (Growth and reproduction) & - & [31] \\ \hline Plant & _Trifolium patense, Lilium multiform, Lepidium sativum, Lactuca sativa_ (Growth) & & \\ \hline Plant & _Tritcium aestivum, Festuca rubra, Trifolium pratense, Lactuca sativa_ (Growth) & commonly recommended in soil & \\ \hline Microorganism & _Escherichia coli_ (Enzyme activity) & soil characteristics & [27] \\ \hline Plant & _Lepidium sativum, Sinapis alba, Sorghum saccharatum_ (Root growth) & - & [37]\({}^{*}\) \\ \hline Collembola & _Paroynchiurus kimi_ (Reproduction) & ecologically relevant, certified for soil & [38]\({}^{*}\) \\ \hline Earthworm & _Eisenia fetida_ (Bioconcentration) & commonly recommended in soil & [32] \\ \hline Collembola & _Proisotoma minuta_ (Avoidance, Reproduction) & worldwide distribution, commonly abundant and representative & [39]\({}^{*}\) \\ \hline Collembola & _Folsomia candida_ (Avoidance) & & \\ \hline Earthworm & _Eisenia andrei_ (Avoidance) & simple, standardized and low-cost & [28] \\ \hline Plant & _Lycopersion esculentum, Avena sativa_ L. & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Summary of previous studies on the criteria for selecting test species for the screening of site-specific soil ecological risk assessments (SERAs). The asterisk (\({}^{*}\)) indicates research that performed bioassays using only one test media. the previous studies using only one or two bioassays, likely had high uncertainty in terms of the ecological risk while screening. Therefore, future studies for site-specific SERAs should select test species that reflect site characteristics, including sensitivity and ecological relevance. Conceptualization, D.K. and Y.-J.A. ; methodology, D.K., T.-Y.L., L.K., R.C., J.I.K., W.H., and J.-I.K. ; investigation, D.K., T.-Y.L., L.K., R.C., J.I.K., H.K., S.-H.N., M.K., W.H., and S.H. ; writing--original draft preparation Y.-J.A. ; writing--review and editing, Y.-J.A. ; supervision, Y.-J.A. ; funding acquisition, Y.-J.A. All authors have read and agreed to the published version of the manuscript. This work was supported by the National Institute of Environment Research (NIER), funded by the Ministry of Environment (MOE) of the Republic of Korea (NIER-SP2020-223). This research was funded by Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Science, ICT and future planning (2020R1A2B5B02001734). This paper was also supported by the Konkuk University Research Fund in 2020, and the MOE through the graduate school of specialization for safe management of chemicals. Not applicable. We thank the Korea Basic Science Institute (KBSI) for the ICP-AES analysis. The authors declare no conflict of interest. References