Microcosm Assay Utilizing Indigenous Soil Invertebrate Community: Ecotoxicological Effects of the Nitramine Explosive CL-20 On Soil Invertebrate Community Structure in a Sandy Loam Soil.

Preservation of soil fertility and structure is essential to sustaining the ecological integrity of terrestrial ecosystems. Use of multi-species tests in assessing soil contamination offers holistic tools for risk assessment, and can provide a broader understanding of the mechanisms by which soil contamination can affect the structure and function of soil ecosystems.  Understanding potential impacts on soil ecosystems of an accidental release of explosives during manufacturing, storage, military training, or disposal operations is important to achieving these goals at military installations. To address the knowledge gap concerning ecotoxicological effects of nitramine explosive CL-20 on soil invertebrates at the community-level, we designed studies to: 1) determine CL-20 toxicity to the soil microinvertebrate community groups in Sassafras sandy loam soil using a 12-week soil Microcosm Assay utilizing the indigenous soil microinvertebrate community; and 2) assess the utility of the Microcosm Assay as a tool for developing ecotoxicological parameters for use in ecological risk assessment. The indigenous microarthropod and nematode communities showed contrasting patterns of sensitivities to CL-20 exposure in SSL soil.  Microcosm Assay, with corresponding community structure analysis, can provide the means for validating ecotoxicity data from standardized laboratory tests, both complimenting and expanding upon the ecotoxicological significance of single-species toxicity tests.