We quantified macrofauna and mesofauna (springtails and mites) in oil polluted soil in order to evaluate the effect of bioremediation such as aeration and compost application to the soil. We also conducted toxicity test with springtail (Folsomia Candida (Willem)) and bacterial community analysis using BiOLOG^[○!R] Eco Plate. The number and biomass of macrofauna were larger in the non-polluted soil and aerated soil (stimulation of indigenous microbial populations) than composted soil (addition of microbial inocula with sewage sludge to polluted soil) and polluted soil. The number of mesofauna was larger in the non-polluted soil than others, reflecting conspicuous difference in springtails. The toxicity test with F. Candida did not show any decrease in survival, growth, and reproduction under field pollution levels. The BiOLOG^[○!R] analysis showed some differences of the bacterial community structure among the soils, and the aerated soil had similar patterns to non-polluted soil in the substrate utilization ability. These studies have shown that the number of mesofauna is much more sensitive to oil pollution and remediation, and a battery of these studies showed that the recovery of soil ecosystem is more advanced in the aerated soil than the composted soil. Thus, although oil concentrations were equivalent between the aerated and composted soil, the aeration technique was superior to the compost application technique from ecological viewpoint.
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