ORIBATID MITES AS INDICATOR SPECIES FOR ESTIMATING THE ENVIRONMENTAL-IMPACT OF CONVENTIONAL AND CONSERVATION TILLAGE PRACTICES

The effects of intensive agricultural practices on oribatid mite distr ibution, number, and diversity were examined. Soil cores were examined from nine fields in which three fields each represented a different t ype of cultivation: conventional (plow-based) till, reduced-till, and no-till. Oribatid heterogeneity, at the species level, was significant ly reduced in the total conventional plow-based fields and reduced-til l fields as compared to the no-till practices. Significant quantitativ e differences existed between conventional and reduced-till fields and between conventional and no-till fields. There was not a quantitative ly significant difference between reduced-till and no-till. The possib le use of oribatid mites as ''indicator'' species for estimating envir onmental impact was noted.