We examined plant species richness and species overlap among 3 site preparation treatments (roll-chop and burn, imazapyr and burn, and imazapyr only) and a mature pine-hardwood forest during 2 years following site preparation in east-central Mississippi. Treatments were applied beginning June 1990. Inventory of plant species in 2 to 5 1.6-ha plots/treatment was completed in spring 1991 and 1992. Species richness did not differ among treatments or between treatments and pine-hardwood forest (P = 0.31). Similarity indices showed no apparent grouping among treatments. All values were approximately equal and were similar within years for all treatments and growth forms. All treatments were more similar to other treatments than to pine-hardwood forest. Intercommunity similarity increased from 1991 to 1992 (P = 0.001). Although the plant communities resulting from site preparation were different in species composition, none could be described as depauperate in number of species or vegetative growth forms